N6-methyltubercidin gives sterile cure in a cutaneous Leishmania amazonensis mouse model

Leishmania is a trypanosomatid parasite that causes skin lesions in its cutaneous form. Current therapies rely on old and expensive drugs, against which the parasites have acquired considerable resistance. Trypanosomatids are unable to synthesize purines relying on salvaging from the host, and nucleoside analogues have emerged as attractive antiparasitic drug candidates. 4-Methyl-7-β-D-ribofuranosyl-7H-pyrrolo[2,3-d]pyrimidine (CL5564), an analogue of tubercidin in which the amine has been replaced by a methyl group, demonstrates activity against Trypanosoma cruzi and Leishmania infantum. Herein, we investigated its in vitro and in vivo activity against L. amazonensis. CL5564 was 6.5-fold (P = 0.0002) more potent than milteforan™ (ML) against intracellular forms in peritoneal mouse macrophages, and highly selective, while combination with ML gave an additive effect. These results stimulated us to study the activity of CL5564 in mouse model of cutaneous Leishmania infection. BALB/c female and male mice infected by L. amazonensis treated with CL5564 (10 mg kg−1, intralesional route for five days) presented a >93% reduction of paw lesion size likely ML given orally at 40 mg kg−1, while the combination (10 + 40 mg kg−1 of CL5564 and ML, respectively) caused >96% reduction. The qPCR confirmed the suppression of parasite load, but only the combination approach reached 66% of parasitological cure. These results support additional studies with nucleoside derivatives.

Block Copolymer Micelles Encapsulating Au(III) Bis(Dithiolene) Complexes as Promising Nanostructures with Antiplasmodial Activity

Block copolymer micelles (BCMs) can be used to improve the solubility of lipophilic drugs and increase their circulation half-life. Hence, BCMs assembled from MePEG-b-PCL were evaluated as drug delivery systems of gold(III) bis(dithiolene) complexes (herein AuS and AuSe) to be employed as antiplasmodial drugs. These complexes exhibited remarkable antiplasmodial activity against liver stages of the Plasmodiumberghei parasite, and low toxicity in a model of zebrafish embryos. To improve the complexes' solubility, BCMs were loaded with AuS, AuSe, and the reference drug primaquine (PQ). PQ-BCMs (D_h = 50.9 ± 2.8 nm), AuSe-BCMs (D_h = 87.1 ± 9.7 nm), and AuS-BCMs (D_h = 72.8 ± 3.1 nm) were obtained with a loading efficiency of 82.5%, 55.5%, and 77.4%, respectively. HPLC analysis and UV-Vis spectrophotometry showed that the compounds did not suffer degradation after encapsulation in BCMs. In vitro release studies suggest that AuS/AuSe-BCMs present a more controlled release compared with PQ-loaded BCMs. The antiplasmodial hepatic activity of the drugs was assessed in vitro and results indicate that both complexes present higher inhibitory activity than PQ, although encapsulated AuS and AuSe presented lower activity than their non-encapsulated counterparts. Nevertheless, these results suggest that the use of BCMs as delivery vehicles for lipophilic metallodrugs, particularly AuS and AuSe, could enable the controlled release of complexes and improve their biocompatibility, constituting a promising alternative to conventional antimalarial treatments.

The Portuguese observatory on occupational psychosocial factors: contribution for public health

 

To achieve the goal of sustainable employment, considering the profile of the Portuguese working population (PWP), is needed a range of strategies to ensure long, productive, and sustainable careers allied with a better quality of working life, health, and wellbeing, but also with public health policies grounded on scientifically validated and reliable data. This is possible through a comprehensive working system approach that ensures workers will be mentally and physically able to remain at work by the balance between work demands and individual resources allied with public health policies transfer into the workplaces by organizations’ leadership and policy makers. The Portuguese Observatory on Occupational Factors (Popsy@Work) aims at addressing this global challenge by: i) digitally collecting psychosocial data on the PWP; ii) implementing and strengthening of a psychosocial occupational health surveillance digital system; iii) providing reference values for the PWP concerning Psychosocial Health; iv) Transferring to society knowledge and best practices; v) Raising awareness on the importance of psychosocial management in occupational settings based on science. Popsy@work is a digital platform that collects and aggregates psychosocial data analytically and creates a visualization hub adding value to data on the PWP and giving science back to society in a usable way, empowering workers, strengthening organizations and grounding public policies. Pospy@Work considers the development of strategic intelligence on levels and inequalities of psychosocial health and well-being in occupational settings by robust metrics and reference data. Creating opportunities for national policy dialogue on inequalities, including the psychosocial health of the PWP through collaboration with diverse sectors identifying and mapping subgroups of populations whose unmet needs require specific outreach measures.

Key messages

“It’s not only the bad side” - Experiences reported by health professionals working with women victims of sexual violence in a Brazilian university specialized outpatient service: A qualitative study

Introduction

Health Psychology is a scientific branch that studies interpersonal relationships in the field of emotions and behavior in clinical settings. Violence against women is a gender-based action that alarmingly affects the population, with sexual violence (SV) being one of its main phenomena. The complexity of the care offered to SV patients by clinical professionals impacts themselves, affecting their personal lives and the quality of their work.

Objectives

To explore symbolic emotional meanings attributed by health professionals to care and follow-up of women victims of SV in state service of reference of the Unified Health System.

Methods

Clinical-Qualitative design was used to guide semi-directed interviews with open-ended questions in-depth. Clinical-Qualitative Content Analysis was employed to treat data. Five participants make up the multi-professional team at the Hospital of the Woman of the State University of Campinas. Theoretical framework chosen to interpret categories was Balintian Medical Psychology.

Results

Three categories were selected for this presentation: The human anguishes as the main challenge and handling of working with sexual violence; “To see things progressing”: to the patient and together with the team, a facilitator of the work; and “I try to leave it on the three’s leaves”: the difficult attempt to separate work from personal life.

Conclusions

Taking care of SV is a very emotionally demanding task. Working with the team and see expected outcomes help clinical professionals deal with negative feelings, avoiding, for example, compensatory traumas. New research about social-cultural impacts of working with SV is important to develop institutional approaches of coping for health teams.

Disclosure

No significant relationships.

Impact of a cardio-oncology rehabilitation program in patients with breast cancer undergoing cardiotoxic treatment

Background

Cancer treatment–related cardiotoxicity (CTrCD) is commonly associated with anthracyclines and anti-HER2 agents which are widely used for the treatment of breast cancer. In order to mitgate CTrCD, exercise-based cardio-oncology rehabilitation (COR) involving a structured exercise program has been proposed.

Objectives

To evaluate the impact of a cardiac-rehabilitation program in breast cancer patients submitted to chemotherapy with known cardiotoxicity.

Methods

A systematic review was performed. Two databases were searched, PubMed and SCOPUS. All randomized or controlled trials and other prospective studies published between 2000 and March 2020 which evaluate the impact of an aerobic exercise program on cardiorespiratory fitness (CRF), health-related quality of life (QOL), vascular/endothelial function as well as cardiac assessment namely through the evaluation of left ventricular function and cardiac biomarkers in patients undergoing anthracycline and/or anti-HER2 treatments were included.

Main results

Fourteen studies were included enrolling 578 breast cancer patients with a mean age of 48.80 years. Regarding the impact of exercise in CRF, 5 studies (n=176) reported a significant improvement of VO2 max. and 4 studies of VO2max./kg (n=137). The peak power output was also improved in 4 studies (n=95) in the exercise-group. Considering the assessment of QOL, 3 studies (n=180) revealed significant differences favoring the exercise-group. The results regarding the evaluation of the LVEF were not clear: 2 studies (n=48) reported a significant decrease on LVEF when compared to baseline at the end of the intervention in both groups, despite the exercise program. However, 2 studies (n=97) showed a significant increase on LVEF in the exercise-group. Three studies (n=82) did not found significant differences in global longitudinal strain between groups. Limited evidence was found in vascular and endothelial functon. In 2 studies (n=50), endothelial function measured by brachial artery flow-mediated dilatation significantly improved in the exercise-group. Two studies (n=98) reported no significant impact of exercise on atenuating the increase of cTnI and BNP levels in the course of chemotherapy. On the other hand, when considering NT-proBNP, an increase in its levels was attenuated in the exercise-group.

Conclusions

This study confirms that exercise-based COR seems to be an effective approach to improve several cardiovascular outcomes and quality of life in breast cancer patients.

Funding Acknowledgement

Type of funding sources: None.

The Impact of Antiretroviral Therapy on Malaria Parasite Transmission

Coendemicity between the human immunodeficiency virus (HIV) and Plasmodium parasites, the causative agents of acquired immunodeficiency syndrome (AIDS) and malaria, respectively, occurs in several regions around the world. Although the impact of the interaction between these two organisms is not well understood, it is thought that the outcome of either disease may be negatively influenced by coinfection. Therefore, it is important to understand how current first-line antiretroviral therapies (ART) might impact Plasmodium infection in these regions. Here, we describe the effect of 18 antiretroviral compounds and of first-line ART on the blood and sporogonic stages of Plasmodium berghei in vitro and in vivo. We show that the combination zidovudine + lamivudine + lopinavir/ritonavir (LPV/r), employed as first-line HIV treatment in the field, has a strong inhibitory activity on the sporogonic stages of P. berghei and that several non-nucleoside reverse transcriptase inhibitors (NNRTI) have a moderate effect on this stage of the parasite’s life cycle. Our results expose the effect of current first-line ART on Plasmodium infection and identify potential alternative therapies for HIV/AIDS that might impact malaria transmission.

From the Hospital Bed to the Laptop at Home: Effects of a Blended Self-Regulated Learning Intervention

Hospitalization poses diverse challenges to school-aged youth well-being and their educational path. Some inpatients, due to the hospitalization duration, frequency or the needed recovery period at home, may struggle when returning to school. To help youth cope with this challenge, several hospitals have been implementing educational interventions tailored to the school-aged children and adolescents needs. Nevertheless, pediatric inpatients with short stays and/or with a recovery period at home usually do not benefit from these interventions. Therefore, the present study implemented a blended intervention (i.e., face-to-face and online) with the aim of training self-regulated learning competences with hospitalized school-aged adolescents with short hospital stays. The intervention was delivered on a weekly basis for eight individual sessions using a story-tool. Results showed the efficacy of the intervention in promoting adolescent's use of, perceived instrumentality of, and self-efficacy for self-regulated learning strategies. Overall, there was a differentiated impact according to the participants' age, grade level, grade retention, and engagement in the intervention. These findings support previous research indicating that hospitals can play an important role as educational contexts even for inpatients with short stays. The blended format used to deliver the self-regulation learning (SRL) training also may be an opportunity to extend these interventions from the hospital to the home context.

Inhibition of Plasmodium sporogonic stages by ivermectin and other avermectins

Background

The transmissible forms of Plasmodium parasites result from a process of sporogony that takes place inside their obligatory mosquito vector and culminates in the formation of mammalian-infective parasite forms. Ivermectin is a member of the avermectin family of endectocides, which has been proposed to inhibit malaria transmission due its insecticidal effect. However, it remains unclear whether ivermectin also exerts a direct action on the parasite’s blood and transmission stages.

Methods

We employed a rodent model of infection to assess the impact of ivermectin treatment on P. berghei asexual and sexual blood forms in vivo. We then made use of a newly established luminescence-based methodology to evaluate the activity of ivermectin and other avermectins against the sporogonic stages of P. berghei parasites in vitro independent of their role on mosquito physiology.

Results

Our results show that whereas ivermectin does not affect the parasite’s parasitemia, gametocytemia or exflagellation in the mammalian host, several members of the avermectin family of compounds exert a strong inhibitory effect on the generation and development of P. berghei oocysts.

Conclusions

Our results shed light on the action of avermectins against Plasmodium transmission stages and highlight the potential of these compounds to help prevent the spread of malaria.

Genotoxic endpoints in a Pb-accumulating pea cultivar: insights into Pb2+ contamination limits

Lead (Pb) persists among the most hazardous contaminant metals. Pb-induced genotoxic effects remain a matter of debate as they are a major cause of plant growth impairment, but assessing Pb genotoxicity requires the selection of Pb-sensitive genotoxic biomarkers. Seedlings of the ecotoxicological model species Pisum sativum L. were exposed to Pb2+ (≤ 2000 mg L-1). Flow cytometry (FCM) revealed that 28 days after, Pb2+ arrested root cell cycle at G2 but no eu/aneuploidies were found. Comet assay and FCM-clastogenicity assays showed that Pb2+ increased DNA breaks in roots at concentrations as low as 20 mg L-1. Leaves showed no variation in DNA-ploidy or cell cycle progression but had increased DNA breaks at the highest Pb2+ dose. We conclude that both Comet assay and the full-peak coefficient of variation (FPCV) were the most relevant endpoints of Pb-phytogenotoxicity. Also, the Pb-induced DNA breaks may be related with the arrest at the G2-checkpoint. Data will be relevant to better define Pb2+ ecogenotoxicological effects and their measuring tools and may contribute to a regulatory debate of this pollutant limits.

Effects of di(2-etilhexil) phthalate on human umbilical artery

Di(2-etilhexil) phthalate (DEHP) is a compound used in plastic materials, which has endocrine disrupting properties. The human DEHP exposure depend on the use of plastics in toys, medical devices and food and beverage containers. The DEHP effects were studied in some physiological systems; nevertheless, the actions in human arteries were never described. We analysed the DEHP effect on endothelium denuded human umbilical artery (HUA), an important artery to ensure gases and nutrients exchange with fetus. We assessed DEHP short-term effects on contractility, occurring few minutes after DEHP is in contact with HUA in the organ bath receptacles. The long-term effects on HUA, observed after 24 h in presence of DEHP, were assessed in the organ bath system, and also through the analysis of receptors expression (5-HT_2A and H₁) and of cellular viability, by using HUA smooth muscle cells. DEHP (1 nM-100 μM) induced a short-term relaxing effect on HUA contracted by 5-HT, histamine or KCl. DEHP long-term exposure of arteries (1 nM, 10 μM and 100 μM) reduced its own relaxant effect on HUA contracted by 5-HT and histamine and, precisely, 24 h exposure to DEHP 1 nM reverted the relaxant effect on 5-HT contractility. Long-term exposure at more than 10 nM of DEHP decreased 5HT_2A receptors expression. In conclusion, DEHP short-term exposition elicit vasodilation of HUA contracted by different agents. DEHP long-term exposition reduced the expression of 5HT_2A receptors. The DEHP long-term exposition decrease the short-term relaxant effect and, at low concentrations can increase the contractile effect of 5-HT.

Mechanical Properties of Topical Anti-Psoriatic Medicines: Implications for Patient Satisfaction with Treatment

Different types of topical preparations are available as anti-psoriatic medicines, semisolid formulations being the preferred dosage forms for the treatment of body lesions. The mechanical characterization of these semisolid formulations is seldom reported, although mechanical features have been recognized to play an important role in treatment acceptability and adherence. The aim of this study was to characterize the mechanical properties of semisolid topical formulations commercially available for psoriasis treatment. One complementary aim was to evaluate patient satisfaction with topical treatment and discuss the results according to the mechanical features of the dosage form. Eight ointments (O 1-8), five creams (C 1-5), one oleogel (G1), and one excipient (E1-petrolatum) were characterized for textural properties (spreadability and penetration tests) and flow behavior. Power law model was fitted to the results. A questionnaire for the assessment of satisfaction with topical medicines used for psoriasis treatment over 6 months was developed and applied to 79 psoriasis patients. All the tested formulations presented a shear-thinning behavior with power law indexes (n) lower than 1. Ointments were distinct from the other dosage forms, since they presented higher consistency coefficients (K), firmness, and adhesiveness and this was evidenced by hierarchical cluster analysis, which identified two clusters based on the mechanical properties. Cluster 1 included the ointments and petrolatum and the cluster 2 enclosed the creams and the gel. The clusters were associated with several attributes classified by patients as analyzed with Fisher's exact test. In all cases, higher satisfaction was observed for cluster 2. The knowledge obtained regarding the influence of the dosage form on the degree of satisfaction with the treatment could be helpful in supporting the selection of the dosage form in clinical practice and thus improve treatment adherence and clinical outcomes. The differences observed between the mechanical properties of the formulations studied may be also relevant to the industry, as guidance to the development of new medicines.

Building knowledge of healthy eating in hospitalized youth: a self-regulated campaign

BACKGROUND

Data from the World Health Organization shows obesity has more than doubled worldwide since 1980. Childhood obesity is mainly associated with external and modifiable factors, as eating habits, existing room for promoting healthy lifestyles. Additionally, learning can take place in contexts other than schools, as the hospital, potentiating the time of hospitalization. Self-regulated learning framework is suited to train the skills necessary for self-management processes and behavioral changes. The aim was to describe and evaluate a campaign designed to increase knowledge about healthy eating by hospitalized school-aged youth.

METHOD

A quasi-experimental design was used. Participants were randomly distributed between the experimental and control groups, each one with 15 participants aged between six and 16 years-old. Information about healthy eating was not provided directly; participants had to reflect and work to build knowledge through activities inspired in the self-regulated learning framework.

RESULTS

Results showed that the experimental group when compared with their counterparts significantly improved their knowledge on healthy eating after taking part in the campaign.

CONCLUSIONS

Campaigns that increase knowledge on healthy eating based on the promotion of self-regulated learning strategies could be incorporated in health promotion programs not only in pediatric units but also in other educational contexts.

A functional glycoproteomics approach identifies CD13 as a novel E-selectin ligand in breast cancer

BACKGROUND

The glycan moieties sialyl-Lewis-X and/or -A (sLe^X/A) are the primary ligands for E-selectin, regulating subsequent tumor cell extravasation into distant organs. However, the nature of the glycoprotein scaffolds displaying these glycans in breast cancer remains unclear and constitutes the focus of the present investigation.

METHODS

We isolated glycoproteins that bind E-selectin from the CF1_T breast cancer cell line, derived from a patient with ductal carcinoma. Proteins were identified using bottom-up proteomics approach by nanoLC-orbitrap LTQ-MS/MS. Data were curated using bioinformatics tools to highlight clinically relevant glycoproteins, which were validated by flow cytometry, Western blot, immunohistochemistry and in-situ proximity ligation assays in clinical samples.

RESULTS

We observed that the CF1_T cell line expressed sLe^X, but not sLe^A and the E-selectin reactivity was mainly on N-glycans. MS and bioinformatics analysis of the targeted glycoproteins, when narrowed down to the most clinically relevant species in breast cancer, identified CD44 glycoprotein (HCELL) and CD13 as key E-selectin ligands. Additionally, the co-expression of sLe^X-CD44 and sLe^X-CD13 was confirmed in clinical breast cancer tissue samples.

CONCLUSIONS

Both CD44 and CD13 glycoforms display sLe^X in breast cancer and bind E-selectin, suggesting a key role in metastasis development. Such observations provide a novel molecular rationale for developing targeted therapeutics.

GENERAL SIGNIFICANCE

While HCELL expression in breast cancer has been previously reported, this is the first study indicating that CD13 functions as an E-selectin ligand in breast cancer. This observation supports previous associations of CD13 with metastasis and draws attention to this glycoprotein as an anti-cancer target.

Inorganic Hg toxicity in plants: A comparison of different genotoxic parameters

Inorganic Mercury (Hg) contamination persists an environmental problem, but its cyto- and genotoxicity in plants remains yet unquantified. To determine the extent of Hg-induced cyto- and genotoxicity, and assess most sensitive endpoints in plants, Pisum sativum L. seedlings were exposed for 14 days to different HgCl2 concentrations up to 100 μM. Shoots and roots from hydroponic exposure presented growth impairment and/or morphological disorders for doses >1 μM, being the roots more sensitive. Plant growth, ploidy changes, clastogenicity (HPCV), cell cycle dynamics (G1-S-G2), Comet-tail moment (TM), Comet-TD, Mitotic-index (MI) and cell proliferation index (CPI) were used to evaluate Hg-induced cyto/genotoxicity. Both leaf and root DNA-ploidy levels, assessed by flow cytometry (FCM), remained unaltered after exposure. Root cell cycle impairment occurred at lower doses (≥1 μM) than structural DNA damages (≥10 μM). Cytostatic effects depended on the Hg concentration, with delays during S-phase at lower doses, and arrests at G1 at higher ones. This arrest was paralleled with decreases of both mitotic index (MI) and cell proliferation index (CPI). DNA fragmentation, assessed by the Comet assay parameters of TD and TM, could be visualized for conditions ≥10 μM, while FCM-clastogenic parameter (FPCV) and micronuclei (MNC) were only altered in roots exposed to 100 μM. We demonstrate that inorganic-Hg induced cytostaticity is detectable even at 1 μM (a value found in contaminated sites), while structural DNA breaks/damage are only visualized in plants at concentrations ≥10 μM. We also demonstrate that among the different techniques tested for cyto- and genotoxicity, TD and TM Comet endpoints were more sensitive than FPCV or MNC. Regarding cytostatic effects, cell cycle analysis by FCM, including the difference in % cell cycle phases and CPI were more sensitive than MI or MNC frequency. Our data contribute to better understand Hg cyto- and genotoxicity in plants and to understand the information and sensitivity provided by each of the genotoxic techniques used.

Experiences During a Psychoeducational Intervention Program Run in a Pediatric Ward: A Qualitative Study

Hospitalization, despite its duration, is likely to result in emotional, social, and academic costs to school-age children and adolescents. Developing adequate psychoeducational activities and assuring inpatients' own class teachers' collaboration, allows for the enhancement of their personal and emotional competences and the maintenance of a connection with school and academic life. These educational programs have been mainly designed for patients with long stays and/or chronic conditions, in the format of Hospital Schools, and typically in pediatric Hospitals. However, the negative effects of hospitalization can be felt in internments of any duration, and children hospitalized in smaller regional hospitals should have access to actions to maintain the connection with their daily life. Thus, this investigation aims to present a psychoeducational intervention program theoretically grounded within the self-regulated learning (SRL) framework, implemented along 1 year in a pediatric ward of a regional hospital to all its school-aged inpatients, regardless of the duration of their stay. The program counts with two facets: the psychoeducational accompaniment and the linkage to school. All the 798 school-aged inpatients (M_age = 11.7; SD_age = 3.71; M_{hospital stay} = 4 days) participated in pedagogical, leisure nature, and SRL activities designed to train transversal skills (e.g., goal-setting). Moreover, inpatients completed assigned study tasks resulting from the linkage between the students' own class teachers and the hospital teacher. The experiences reported by parents/caregivers and class teachers of the inpatients enrolling in the intervention allowed the researchers to reflect on the potential advantages of implementing a psychoeducational intervention to hospitalized children and adolescents that is: individually tailored, focused on leisure playful theoretically grounded activities that allow learning to naturally occur, and designed to facilitate school re-entry after hospital discharge. Parents/caregivers highlighted that the program helped in the preparation for surgery and facilitated the hospitalization process, aided in the distraction from the health condition, promoted SRL competences, and facilitated the communication and linkage with school life. Class teachers emphasized the relevance of the program, particularly in the liaison between hospital and school, in the academic and psycho-emotional and leisure-educational support provided, and in smoothing the school re-entry.

An Innate Immunity Pathway in the Moss Physcomitrella patens

MAP kinase (MPK) cascades in Arabidopsis thaliana and other vascular plants are activated by developmental cues, abiotic stress, and pathogen infection. Much less is known of MPK functions in nonvascular land plants such as the moss Physcomitrella patens Here, we provide evidence for a signaling pathway in P. patens required for immunity triggered by pathogen associated molecular patterns (PAMPs). This pathway induces rapid growth inhibition, a novel fluorescence burst, cell wall depositions, and accumulation of defense-related transcripts. Two P. patens MPKs (MPK4a and MPK4b) are phosphorylated and activated in response to PAMPs. This activation in response to the fungal PAMP chitin requires a chitin receptor and one or more MAP kinase kinase kinases and MAP kinase kinases. Knockout lines of MPK4a appear wild type but have increased susceptibility to the pathogenic fungi Botrytis cinerea and Alternaria brassisicola Both PAMPs and osmotic stress activate some of the same MPKs in Arabidopsis. In contrast, abscisic acid treatment or osmotic stress of P. patens does not activate MPK4a or any other MPK, but activates at least one SnRK2 kinase. Signaling via MPK4a may therefore be specific to immunity, and the moss relies on other pathways to respond to osmotic stress.

Photosynthesis light-independent reactions are sensitive biomarkers to monitor lead phytotoxicity in a Pb-tolerant Pisum sativum cultivar

Lead (Pb) environmental contamination remains prevalent. Pisum sativum L. plants have been used in ecotoxicological studies, but some cultivars showed to tolerate and accumulate some levels of Pb, opening new perspectives to their use in phytoremediation approaches. However, the putative use of pea plants in phytoremediation requires reliable toxicity endpoints. Here, we evaluated the sensitivity of a large number of photosynthesis-related biomarkers in Pb-exposed pea plants. Plants (cv. "Corne de Bélier") were exposed to Pb concentrations up to 1,000 mg kg(-1) soil during 28 days. The photosynthetic potential biomarkers that were analyzed included pigments, chlorophyll (Chl) a fluorescence, gas exchange, ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) activity, and carbohydrates. Flow cytometry (FCM) was also used to assess the morpho-functional status of chloroplasts. Finally, Pb-induced nutrient disorders were also evaluated. Net CO2 assimilation rate (A) and RuBisCO activity decreased strongly in Pb-exposed plants. Plant dry mass (DM) accumulation, however, was only reduced in the higher Pb concentrations tested (500 and 1,000 mg kg(-1) soil). Pigment contents increased solely in plants exposed to the largest Pb concentration, and in addition, the parameters related to the light-dependent reactions of photosynthesis, Fv/Fm and ΦPSII, were not affected by Pb exposure. In contrast to this, carbohydrates showed an overall tendency to increase in Pb-exposed plants. The morphological status of chloroplasts was affected by Pb exposure, with a general trend of volume decrease and granularity increase. These results point the endpoints related to the light-independent reactions of photosynthesis as more sensitive predictors of Pb-toxicity than the light-dependent reactions ones. Among the endpoints related to the light-independent photosynthesis reactions, RuBisCO activity and A were found to be the most sensitive. We discuss here the advantages of using these parameters as biomarkers for Pb toxicity in plants. Finally, we report that, despite showing physiological disorders, these cultivar plants survived and accumulated high doses of Pb, and their use in environmental/decontamination studies is open to debate.

Exposure to Cr(VI) induces organ dependent MSI in two loci related with photophosphorylation and with glutamine metabolism

Chromium (Cr), as a mutagenic agent in plants, has received less attention than other metal pollutants. To understand if Cr induces microsatellite instability (MSI), Pisum sativum seedlings were exposed for 28 days to different concentrations of Cr(VI) up to 2000mgL(-1), and the genetic instability of ten microsatellites (SSRs) was analyzed. In plants exposed to Cr(VI) up to 1000mg L(-1), MSI was never observed. However, roots exposed to 2000mgL(-1) displayed MSI in two of the loci analyzed, corresponding to a mutation rate of 8.3%. SSR2 (inserted in the locus for plastid photosystem I 24kDa light harvesting protein) and SSR6 (inserted in the locus for P. sativum glutamine synthetase) from Cr(VI)-treated roots presented alleles with, respectively, less 6bp and more 3bp than the corresponding controls. This report demonstrates that: (a) SSRs technique is sensitive to detect Cr-induced mutagenicity in plants, being Cr-induced-MSI dose and organ dependent (roots are more sensitive); (b) two Cr-sensitive loci are related with thylakoid photophosphorylation and with glutamine synthetase, respectively; (c) despite MSI is induced by Cr(VI), it only occurs in plants exposed to concentrations higher than 1000mgL(-1) (values rarely found in real scenarios). Considering these data, we also discuss the known functional changes induced by Cr(VI) in photosynthesis and in glutamine synthetase activity.

Understanding gypsy children’s conceptions of learning: A phenomenographic study

In Portugal, as in other European countries, gypsy children remain largely at the margins of the educational system. Their underachievement and the associated dropout rates from school are serious educational issues and factors contributing to their marginalization in society. However, there is limited research qualitatively examining the different ways in which gypsy children think about learning. The current study examined data provided by 26 Portuguese gypsy elementary school children ranging from 9- to 13- years-old. Data analysis presented an outcome space representing the gypsy children’s qualitatively different conceptions of learning. Accordingly with their gypsy culture, these Portuguese students perceived their learning of basic numeracy and literacy skills as important for helping their families selling at fairs. These children indicated that they do not intend to continue studying beyond elementary school as they believe that learning of these basic skills is enough for living as a gypsy. The implications for educational processes and school practices are discussed.

Pb2+ exposure induced microsatellite instability in Pisum sativum in a locus related with glutamine metabolism

Lead (Pb) is a toxic element, but its putative mutagenic effects in plant cells, using molecular markers, remain to unveil. To evaluate if Pb induces mutagenicity, Pisum sativum L. seedlings were exposed to Pb(2+) (up to 2000 mg L(-1)) for 28 days and the instability of microsatellites (or Simple Sequence Repeats, SSR) was analyzed in leaves and roots. The analysis of eight selected microsatellites (SSR1-SSR8) demonstrated that only at the highest dosage microsatellite instability (MSI) occurred, at a frequency of 4.2%. Changes were detected in one microsatellite (SSR6) that is inserted in the locus for glutamine synthetase. SSR6 products of roots exposed to the highest concentration of Pb were 3 bp larger than those of the control. Our data demonstrate that: (a) SSR technique is sensitive to detect Pb-induced mutagenicity in plants. MSI instability is Pb dose dependent and organ dependent (roots are more sensitive); (b) the Pb-sensitive SSR6 is inserted in the glutamine synthetase locus, with still unknown relation with functional changes of this enzyme; (c) Pb levels inducing MSI are much above the maximum admitted levels in some European Union countries for agricultural purpose waters. In conclusion, we propose here the potential use of SSR to evaluate Pb(2+)-induced mutagenicity, in combination with other genetic markers.

Aortic clamping in pancreas transplantation: is there any harm to the transplanted kidney graft?

INTRODUCTION

Some special situations may require aortic clamping during pancreas transplantation (PT). The most important problem is ischemic injury to a previous transplanted kidney. We sought to demonstrate experience with aortic clamping in PT without special kidney allograft protection measures and its impact on kidney function.

METHODS

Retrospective study that analyzed 6 patients who underwent PT (5 pancreas after kidney and 1 simultaneous pancreas-kidney) with aortic clamping. In all cases, the pancreas graft was placed on the right with retrocolic portal-enteric drainage. Serum creatinine was evaluated pre- and posttransplantation.

RESULTS

The average clamping time was 19 minutes. The mean serum creatinine was 1.1, 1.15, 0.95, and 1.0, respectively, at pre and postoperative days 1 and 7 and at hospital discharge. Patient, kidney, and pancreatic graft survivals were 100%, 100%, and 83%, respectively.

CONCLUSION

The need for aortic clamping in selected cases of PT did not seem to affect the transplanted kidney, even without protective measures, provided that the ischemic time was short.

Chromium (VI) induces toxicity at different photosynthetic levels in pea

In order to comprehensively characterize the effects of Cr (VI) on the photosynthetic performance of Pisum sativum, plants irrigated with Cr solutions (ranging from 20 to 2000 mg l(-1)) were evaluated using the following classical endpoints: gas exchange parameters, chlorophyll a (Chl a) fluorescence, leaf pigments, Rubisco activity, soluble sugars and starch content. Flow cytometry (FCM) was applied in an innovative approach to evaluate the morphological and fluorescence emission status of chloroplasts from plants exposed to Cr (VI). The parameters related to gas exchange, net CO(2) assimilation rate (A) and Rubisco activity were severally affected by Cr exposure, in some cases even at the lowest dosage used. While all biomarkers used to measure Chl a fluorescence indicated a decrease in fluorescence at the maximum dosage, pigment contents significantly increased in response to Cr (VI). The morphology of chloroplasts also was altered by Cr (VI) exposure, as a volume decrease was observed. Soluble sugars and starch showed an overall tendency to increase in Cr (VI) exposed plants, but sucrose and glucose decreased highly when exposed to 2000 mg l(-1). In conclusion, our results indicate that Cr (VI) affects photosynthesis at several levels, but the most Cr (VI)-sensitive endpoints were chloroplast morphology and biochemical processes; only at higher dosages the photochemical efficiency is compromised.

Cr(VI) induces DNA damage, cell cycle arrest and polyploidization: a flow cytometric and comet assay study in Pisum sativum

Chromium(VI) is recognized as the most toxic valency of Cr, but its genotoxicity and cytostaticity in plants is still poorly studied. In order to analyze Cr(VI) cyto- and gentotoxicity, Pisum sativum L. plants were grown in soil and watered with solutions with different concentrations of Cr up to 2000 mg/L. After 28 days of exposure, leaves showed no significant variations in either cell cycle dynamics or ploidy level. As for DNA damage, flow cytometric (FCM) histograms showed significant differences in full peak coefficient of variation (FPCV) values, suggesting clastogenicity. This is paralleled by the Comet assay results, showing an increase in DNA damage for 1000 and 2000 mg/L. In roots, exposure to 2000 mg/L resulted in cell cycle arrest at the G(2)/M checkpoint. It was also verified that under the same conditions 40% of the individuals analyzed suffered polyploidization having both 2C and 4C levels. DNA damage analysis by the Comet assay and FCM revealed dose-dependent increases in DNA damage and FPCV. Through this, we have unequivocally demonstrated for the first time in plants that Cr exposure can result in DNA damage, cell cycle arrest, and polyploidization. Moreover, we critically compare the validity of the Comet assay and FCM in evaluating cytogenetic toxicity tests in plants and demonstrate that the data provided by both techniques complement each other and present high correlation levels. In conclusion, the data presented provides new insight on Cr effects in plants in general and supports the use of the parameters tested in this study as reliable endpoints for this metal toxicity in plants.

The invasion route for an insect pest species: the tobacco aphid in the New World

Biological invasions are rapid evolutionary events in which populations are usually subject to a founder event during introduction followed by rapid adaptation to the new environment. Molecular tools and Bayesian approaches have shown their utility in exploring different evolutionary scenarios regarding the invasion routes of introduced species. We examined the situation for the tobacco aphid, Myzus persicae nicotianae, a recently introduced aphid species in Chile. Using seven microsatellite loci and approximate Bayesian computation, we studied populations of the tobacco aphid sampled from several American and European countries, identifying the most likely source populations and tracking the route of introduction to Chile. Our population genetic data are consistent with available historical information, pointing to an introduction route of the tobacco aphid from Europe and/or from other putative populations (e.g. Asia) with subsequent introduction through North America to South America. Evidence of multiple introductions to North America from different genetic pools, with successive loss of genetic diversity from Europe towards North America and a strong bottleneck during the southward introduction to South America, was also found. Additionally, we examined the special case of a widespread multilocus genotype that was found in all American countries examined. This case provides further evidence for the existence of highly successful genotypes or 'superclones' in asexually reproducing organisms.

Low power laser in the prevention of induced oral mucositis in bone marrow transplantation patients

6541

Background: High-dose chemotherapy followed by bone marrow transplant produces undesirable effects in the oral cavity leading to oral mucositis (OM) that may be a painful and debilitating side-effect. Laser therapy has been used to improve the symptoms and duration of already established OM in this group of patients (pts). Recent data suggest the upfront use of laser therapy may decrease the incidence of OM. Methods: Through the use of upfront LPL as protecting and modulating therapy of the oral mucosa membrane, we evaluated the potential for a reduction in the incidence and/or severity of OM in pts submitted to autologous (AT) or allogeneic (AL) bone marrow transplant (BMT). Sample size was based on estimative of P0 control = 0.6 and a P1 LPL = 0.1, β = 0.1; α= 0.05. From Jan 2004 to May 2005, 38 pts treated at the National Bone Marrow Transplant Center in Rio de Janeiro were randomized into a group of 19 pts that received and a group of 19 that did not receive the application of the preventive LPL from the beginning of the conditioning. The irradiation was used an diode InGaAlP, emiting light at 660 nm wavelenght with output power of 50 mW, giving an energy density of 4 J/cm2. The tip of the laser device touched the oral mucosa. The evaluation of OM was done by different investigators both by WHO and OMAS scale. Results: The male to female ratio was 60.5/39.5%. The median age 37 (19–56). The frequency of AT and AL was 73.7 (15.8% non related) vs 26.3%. In the LPL group 94.8% of pts had OM WHO grade < 2 (including 63.2% with grade 0), whereas in the control group 68.4% of pts had OM grade III and IV (p<0,001). Remarkably the HR for grade II, III and IV OM was 0.41 (CI 95% 0.22–0.75, p = 0,002) and for grade III and IV was 0.07 (CI 95%0.11–0.53, p<0,000). Using OMAS scale by the calculation of ulcerous area, 73.6% of LPL pts presented lesions of 0 to 3 cm2, whereas 73.6% of the control group presented ulcers from 9.1 to 18 cm2 (p=0.003). An agreement was observed among investigators (index of 81.7%) and between WHO and OMAS scale (p<0,001). Conclusion: Our results indicate that the use of upfront LPL in bone marrow transplantation patients is a powerful instrument in reducing the incidence of OM and is now standard in our center.

No significant financial relationships to disclose.

Tirofiban (Aggrastat®) Protects Platelets and Decreases Platelet-Granulocyte Binding in an Extracorporeal Circulation Model

OBJECTIVES

Extracorporeal circulation (ECC) induces platelet activation and inflammation with potentially life-threatening organ dysfunction. Short-acting GP IIb/IIIa inhibitors like tirofiban and eptifibatide protect platelets during ECC without increasing bleeding complications and may reduce inflammation. This study investigates anti-thrombotic and anti-inflammatory effects of different platelet inhibitors.

METHODS

Control (untreated) and treated (using either 150 ng/mL tirofiban, 2.5 microg/mL eptifibatide, 0.7 microg/mL milrinone, 15 microg/mL dipyridamol, or 300 KIU/mL aprotinin) heparinized blood of healthy volunteers (n = 6) was recirculated in a well-established ECC model (Chandler loop). Percentage of platelet aggregates, P-selectin-expressing (activated) platelets, CD15-positive aggregates (indicating proinflammatory platelet-granulocyte binding), and platelet counts were determined before (baseline) and after 30 minutes recirculation in unstimulated and ADP-stimulated samples using flow cytometry. Statistical analysis was performed using multifactor ANOVA after transforming the data (logarithms for counts and log odds for percentages). Least square means were backtransformed to obtain appropriate means and their 95 % confidence intervals. Multiple post-hoc comparisons were performed by Tukey's HSD test with a global alpha of 5 %.

RESULTS

Significant inhibition was observed for: 1) ECC-induced platelet aggregation by tirofiban (unstimulated: 2.2-fold/stimulated: 2.46-fold), eptifibatide (unstimulated: 1.96-fold/stimulated: 2.65-fold), and milrinone (unstimulated: 1.87-fold/stimulated: 1.37-fold); 2) ECC-induced P-selectin expression by tirofiban (unstimulated: 3.95-fold/stimulated: 2.54-fold), and eptifibatide (unstimulated: 5.87-fold/stimulated: 3.28-fold); 3) ECC-induced platelet loss by tirofiban (1.27-fold), and eptifibatide (1.25-fold); 4) ECC-induced platelet-granulocyte binding by tirofiban (unstimulated: 2.25-fold/stimulated: 1.59-fold), but not by eptifibatide.

CONCLUSIONS

Amongst the investigated drugs only GP IIb/IIIa inhibitors decreased activation, aggregation, and loss of platelets during ECC but acted differently on platelet-granulocyte interaction. A short-acting GP IIb/IIIa inhibitor with the potential to inhibit platelet activation and platelet-leukocyte interaction should be considered both for platelet protection and inhibition of platelet-mediated inflammation during ECC.

Hypothermia-Induced Platelet Aggregation: No Effect of Aprotinin (Trasylol®) but Inhibition by Eptifibatide (Integrilin®)

OBJECTIVES

The serine-protease inhibitor aprotinin protects platelet function during cardiopulmonary bypass. However, its safety and efficacy during deep hypothermic circulatory arrest (DHCA) is controversial, and aprotinin is suspected to cause thrombosis especially during hypothermia. The platelet GP IIb/IIIa inhibitor eptifibatide has been assumed to preserve platelet function during cardiopulmonary bypass without increasing bleeding complications. The aim of this study was to compare the effect of aprotinin and eptifibatide on platelet function under conditions of DHCA.

METHODS

Heparinized blood from healthy volunteers (n = 10) was incubated in stasis for 30 minutes at 18 degrees C to simulate DHCA and compared to samples incubated at 37 degrees C. The effect of eptifibatide (2.5 microg/ml) and aprotinin (300 KIU/ml) on platelets under these conditions was analyzed by flow cytometry. Platelet aggregates were identified using CD41-antibody binding and size. GPIIb/IIIa function was evaluated with the activation-specific antibody PAC-1 after stimulation with 10 microM ADP. Aggregate numbers and antibody mean-fluorescence are reported as mean +/- standard deviation.

RESULTS

Hypothermia induced a 2.5-fold increase of aggregates ( p < 0.001) and a 2.6-fold increase of GPIIb/IIIa activation ( p < 0.001). This effect was not influenced by aprotinin but almost completely inhibited by eptifibatide ( p < 0.001).

CONCLUSIONS

Aprotinin has no procoagulatory effect on platelet function during hypothermia but is not protective either. Eptifibatide inhibits hypothermia-induced platelet aggregation in vitro and may prevent aggregate sequestration in the microvasculature and consecutive ischemic organ damage in vivo.

Squamous cell carcinoma of the breast

Squamous carcinoma of the breast (SCB) is a rare entity. For its diagnosis, the exclusion of squamous cell carcinoma of local cutaneous structures and metastasis of distant squamous carcinoma are mandatory. The aim was to retrospectively evaluate the prevalence, epidemiological and clinical characteristics of the cases of SCB, studied in our institution, between January 1985 and December 1996. The diagnosis was histopathological. We studied the patients' demographic data and tumour characteristics. In the 11-year study period, 5791 patients with breast carcinoma were admitted to our Institution, seven (0.1%) of which were SCB. All seven patients were female and Caucasian. Their average age was 63 years (range 24-82). The presentation was always a breast lump. Five patients were in Stage II-A and two in Stage II-B. All tumours were hormone-receptor negative. The initial treatment was surgery and four patients received adjuvant radiotherapy. The median follow-up was 64 months. No relapses were diagnosed. SCB is a rare entity. The initial therapeutic approach should be surgical. There is still no consensus regarding adjuvant therapy. The prognosis of this type of breast cancer is still the subject of controversy with some series, including the present study, suggesting an indolent clinical course and a relatively good prognosis.

CD8+ lymphocytes in the blister fluid of severe acute cutaneous graft-versus-host disease: further similarities with toxic epidermal necrolysis

BACKGROUND

Graft-versus-host disease (GvHD) remains the major toxicity of allogeneic bone marrow transplantation (BMT). In the acute form of the disease, the differential diagnosis includes viral rash and drug eruptions.

METHODS

We report two patients with chronic myeloid leukemia submitted to allogeneic BMT who developed a severe form of acute cutaneous GvHD, with clinical and histological pictures mimicking toxic epidermal necrolysis (TEN).

RESULTS

We found a predominance of peripheral CD8+ T lymphocytes and, at the same time, studying the cellular profile of the blister fluid, just in the beginning of blister eruption, we also found a high proportion of CD8+ T lymphocytes, mainly CD8+CD57-.

CONCLUSION

These data are in agreement with previous reports of the presence of CD8+ T cells in the blister fluid of patients with TEN, further emphasizing similar immunoinflammatory pathways in both diseases.

Biphasic effects of selegiline on striatal dopamine: lack of effect on methamphetamine-induced dopamine depletion

We tested the hypothesis that selegiline can attenuate dopamine depletion if administered following high doses of methamphetamine that cause neurotoxicity in the striatum. Methamphetamine produced decreases of 50% or greater in both striatal concentrations of dopamine and combined concentrations of homovanillic acid and DOPAC in mice. For animals not exposed to methamphetamine, chronic treatment with selegiline over 18 days caused biphasic effects on striatal dopamine content, with decreases, no effect, or increases observed for mice receiving treatment with 0.02, 0.2, and 2.0 mg/kg, respectively. Selegiline failed to modify methamphetamine-induced reductions in striatal dopamine content or combined concentrations of homovanillic acid and DOPAC. Significant increases in mortality following the onset of selegiline treatment (24 hours after the initial dose of methamphetamine) occurred in methamphetamine-treated mice that received saline or 2.0 mg/kg of selegiline, but not for mice treated with 0.02 or 0.2 mg/kg of selegiline. These results indicate that selegiline fails to attenuate dopamine depletion when administered chronically following exposure to methamphetamine, but may attenuate methamphetamine-induced mortality. In control animals that did not receive methamphetamine, low doses of selegiline produced decreases the concentration of striatal dopamine, while high dose treatment caused increases in striatal dopamine content.

Prognostic value of Ki-67 expression in localized cutaneous malignant melanoma

BACKGROUND

The proliferative activity of some tumors is related to the development of metastatic disease and survival. Thus it could be used as a potential prognostic variable.

OBJECTIVE

The purpose of this study was to determine the prognostic value of the Ki-67 index and of a "proliferation-based prognostic index" (PBPI, derived as tumor thickness x Ki-67 index/100) in localized cutaneous malignant melanoma (CMM).

METHODS

The Ki-67 index (percent of total tumor nuclei) was determined in a series of 84 localized CMMs, with the use of the alkaline phosphatase-antialkaline phosphatase labeling method in formalin-fixed, paraffin-embedded material, and was correlated with other prognostic variables. Survival analysis was performed to determine whether the Ki-67 index and the PBPI could be predictive of metastatic spread or recurrent disease. A stratified analysis of these two parameters according to the tumor thickness was done.

RESULTS

An association among the Ki-67 index and location, Clark level, tumor thickness and stage, and prognostic index was detected. Increased Ki-67 index and PBPI were associated with poorer overall survival (P =.03 and P <.0001, respectively) and disease-free survival (P =.01 and P <.0001, respectively). However, after stratification for thickness, only the PBPI showed independent prognostic significance, restricted to tumors thicker than 4 mm (P =. 03).

CONCLUSION

The determination of the PBPI in CMM conveys prognostic information for localized thick (>4 mm) CMM, identifying two groups of patients with distinct outcome.

Correlation between HIV and HCV in Brazilian prisoners: evidence for parenteral transmission inside prison

OBJECTIVE

It is an accepted fact that confinement conditions increase the risk of some infections related to sexual and/or injecting drugs practices. Mathematical techniques were applied to estimate time-dependent incidence densities of HIV infection among inmates.

METHODS

A total of 631 prisoners from a Brazilian prison with 4,900 inmates at that time were interviewed and their blood drawn. Risky behavior for HIV infection was analyzed, and serological tests for HIV, hepatitis C and syphilis were performed, intended as surrogates for parenteral and sexual HIV transmission, respectively. Mathematical techniques were used to estimate the incidence density ratio, as related to the time of imprisonment.

RESULTS

Prevalence were: HIV - 16%; HCV - 34%; and syphilis - 18%. The main risk behaviors related to HIV infection were HCV prevalence (OR=10.49) and the acknowledged use of injecting drugs (OR=3.36). Incidence density ratio derivation showed that the risk of acquiring HIV infection increases with the time of imprisonment, peaking around three years after incarceration.

CONCLUSIONS

The correlation between HIV and HCV seroprevalence and the results of the mathematical analysis suggest that HIV transmission in this population is predominantly due to parenteral exposure by injecting drug, and that it increases with time of imprisonment.