Alterações da sinalização purinérgica gastrointestinal na Diabetes

A dismotilidade entérica é uma complicação a longo prazo da Diabetes mellitus (DM) que causa desconforto significativo em 76% dos pacientes diabéticos. Sabendo que as purinas estão envolvidas na neuromodulação colinérgica e que no SNC de animais diabéticos foram encontradas alterações na expressão de recetores purinérgicos, decidimos investigar se na dismotilidade diabética a neuromodulação purinérgica se encontra preservada. O modelo animal escolhido de diabetes tipo I resultou da administração de estreptozotocina (STZ, 55 mg/kg, IP) a ratazanas (Rattus norvegicus, Wistar). Este modelo STZ provou ser adequado para o estudo, apresentando 2 semanas após a indução polidipsia, poliúria, polifagia, hiperglicemia e um atraso da motilidade gastrointestinal. A caraterização morfológica macroscópica dos animais STZ revelou um aumento significativo do cego e do intestino. Funcionalmente, estudos preliminares indicam que as contrações espontâneas do íleo dos animais STZ perdem ritmicidade e apresentam maior amplitude que as dos animais controlo de uma forma insensível à TTX, sugerindo o comprometimento das ICC. Paralelamente, estudos imagiológicos revelaram uma perda neuronal mioentérica, principalmente de neurónios nitrérgicos, sendo os colinérgicos preservados. Contudo, a resposta muscular do íleo de animais diabéticos à acetilcolina (ACh) foi inferior à dos controlos, estando a libertação de ACh modulada pela adenosina modificada. Verificou-se que a inibição promovida pelos recetores A1 se mantinha, mas que se perdia a facilitação mediada pela ativação de recetores A2A, cuja imunorreatividade também se encontrava diminuída. Curiosamente, apesar do catabolismo do ATP e dos seus metabolitos estar aumentado nos animais STZ, não se verificou um aumento dos níveis extracelulares de adenosina. Nos animais diabéticos a adenosina é rapidamente desaminada e recaptada por transportadores de nucleósidos, com principal relevância para os concentrativos, sendo os equilibrativos responsáveis pelo transporte da adenosina em animais controlo. Os resultados apresentados nesta tese sugerem que a dismotilidade diabética pode dever-se à perda da atividade nitrérgica, das ICC e da neuromodulação purinérgica mediada por recetores A2A, comprometendo assim a libertação de ACh e consequentemente a motilidade GI

Caracterização química e microbiológica de pêras secadas em estufa solar.

A secagem solar é umas das técnicas mais antigas de conservação de frutos, particularmente os de pequena dimensão. Durante este processo ocorrem também modificações das características químicas e sensoriais dos frutos, que os podem tornar mais apelativos para o consumidor. Neste contexto, a pêra secada da variedade de S. Bartolomeu – pêra passa de Viseu surge como um produto que perde a sua acentuada adstringência com a secagem, reunindo características ímpares como a forma, a cor, o paladar, o cheiro e a capacidade de conservação (Ferreira et al., 2002). No entanto, o decréscimo da sua produção tem conduzido ao aparecimento e secagem de outras variedades regionais, também de pequenas dimensões para a produção da pêra passa. O objectivo deste trabalho consistiu na avaliação das propriedades nutricionais em fresco e após a secagem, efectuada em estufa solar, de quatro variedades regionais de pêras: S. Bartolomeu, Carapinheira Branca, Amêndoa e Amorim provenientes de Coimbra. Nas pêras secadas foram também efectuadas análises microbiológicas com vista à determinação dos mesófilos, dos bolores, das leveduras e dos coliformes totais presentes. Dos resultados obtidos concluiu-se que a polpa em fresco de todas as variedades de pêras estudadas é pobre em proteína e rica em açúcares totais, tal como acontece para a generalidade dos frutos. No entanto, os valores de fibra dietética total para as quatro variedades estão compreendidos entre cerca de 12% a 15% em massa seca, sendo superiores aos obtidos para a generalidade dos frutos e alguns cereais que, no geral, são considerados a melhor fonte de fibra dietética. Os resultados indicam que a secagem em estufa solar não afectou as características nutricionais avaliadas das quatro variedades secadas com excepção dos açúcares totais. A gama de valores de actividade da água e dos níveis populacionais de microorganismos encontrados nas diferentes variedades de pêras permite inferir que este tipo de alimentos será potencialmente seguro do ponto de vista microbiológico. Este comportamento permite-nos sugerir que as variedades Carapinheira Branca, Amêndoa e Amorim são uma potencial alternativa à variedade de S. Bartolomeu para a produção de pêra passa

Diabetic rats lose A2A receptor-mediated facilitation of ileal myenteric cholinergic neurotransmission

Enteric dysmotility is a long-term complication of Diabetes mellitus that causes significant discomfort in 76% of diabetic outpatients. Knowing that purines may be involved in synaptic transmission modifications in the CNS of diabetic rats, we decided to investigate if purinergic dysfunction could also play a role in diabetic enteric neuropathy in rats.info:eu-repo/semantics/publishedVersio

Multi-organ NMR metabolomics to assess in vivo overall metabolic impact of cisplatin in mice

This work describes, to our knowledge, the first NMR metabolomics analysis of mice kidney, liver, and breast tissue in response to cisplatin exposure, in search of early metabolic signatures of cisplatin biotoxicity. Balb/c mice were exposed to a single 3.5 mg/kg dose of cisplatin and then euthanized; organs (kidney, liver, breast tissue) were collected at 1, 12, and 48 h. Polar tissue extracts were analyzed by NMR spectroscopy, and the resulting spectra were studied by multivariate and univariate analyses. The results enabled the identification of the most significant deviant metabolite levels at each time point, and for each tissue type, and showed that the largest metabolic impact occurs for kidney, as early as 1 h post-injection. Kidney tissue showed a marked depletion in several amino acids, comprised in an overall 13-metabolites signature. The highest number of changes in all tissues was noted at 12 h, although many of those recovered to control levels at 48 h, with the exception of some persistently deviant tissue-specific metabolites, thus enabling the identification of relatively longer-term effects of cDDP. This work reports, for the first time, early (1-48 h) concomitant effects of cDDP in kidney, liver, and breast tissue metabolism, thus contributing to the understanding of multi-organ cDDP biotoxicity.publishe

Novel insights into mice multi-organ metabolism upon exposure to a potential anticancer Pd(II)-agent

Pd(II)-compounds are presently regarded as promising anticancer drugs, as an alternative to Pt(II)-based drugs (e.g., cisplatin), which typically trigger severe side-effects and acquired resistance. Dinuclear Pd(II) complexes with biogenic polyamines such as spermine (Pd2Spm) have exhibited particularly beneficial cytotoxic properties, hence unveiling the importance of understanding their impact on organism metabolism. The present study reports the first nuclear magnetic resonance (NMR)-based metabolomics study to assess the in vivo impact of Pd2Spm on the metabolism of healthy mice, to identify metabolic markers with possible relation to biotoxicity/side-effects and their dynamics. The changes in the metabolic profiles of both aqueous and lipophilic extracts of mice kidney, liver, and breast tissues were evaluated, as a function of drug-exposure time, using cisplatin as a reference drug. A putative interpretation was advanced for the metabolic deviations specifically triggered by Pd2Spm, this compound generally inducing faster metabolic response and recovery to control levels for all organs tested, compared to cisplatin (except for kidney lipid metabolism). These results constitute encouraging preliminary metabolic data suggestive of potential lower negative effects of Pd2Spm administration.This research was developed within the scope of the CICECO—Aveiro Institute of Materials, with references UIDB/50011/2020 and UIDP/50011/2020, financed by national funds through the Portuguese Foundation for Science and Technology (FCT/MEC) and when appropriate co-financed by European Regional Development Fund (FEDER) under the PT2020 Partnership Agreement. This work was also funded by the FCT through UIDB/00070/2020 (ALMBC and MPMM), PO-CI-01-0145-FEDER-0016786, and Centro-01-0145-FEDER-029956 (co-financed by COMPETE 2020, Portugal 2020 and European Community through FEDER). It also received financial support from PT national funds (FCT/MCTES, Fundação para a Ciência e Tecnologia and Ministério da Ciência, Tecnologia e Ensino Superior) through the project UIDB/50006/2020. We also acknowledge the Portuguese National NMR Network (PTNMR), supported by FCT funds as the NMR spectrometer used is part of PTNMR and partially supported by Infrastructure Project Nº 022161 (co-financed by FEDER through COMPETE 2020, POCI and PORL, and the FCT through PIDDAC). M.V. thanks the FCT and the PhD Program in the department of Medicines and Pharmaceutical Innovation (i3DU) for their PhD grant PD/BD/135460/2017 and T.J.C. thanks FCT for their PhD grant SFRH/BD/145920/2019, both grants were funded by the European Social Fund of the European Union and national funds FCT/MCTES.publishe

P-glycoprotein activation by 1-(propan-2-ylamino)-4-propoxy-9H-thioxanthen-9-one (TX5) in rat distal ileum: ex vivo and in vivo studies

In vitro studies showed that 1-(propan-2-ylamino)-4-propoxy-9H-thioxanthen-9-one (TX5) increases P-glycoprotein (P-gp) expression and activity in Caco-2 cells, preventing xenobiotic toxicity. The present study aimed at investigating TX5 effects on P-gp expression/activity using Wistar Han rats: a) in vivo, evaluating intestinal P-gp activity; b) ex vivo, evaluating P-gp expression in ileum brush border membranes (BBM) and P-gp activity in everted intestinal sacs; c) ex vivo, evaluating P-gp activity in everted intestinal sacs of the distal and proximal ileum. TX5 (30 mg/kg, b.w.), gavage, activated P-gp in vivo, given the significant decrease in the AUC of digoxin (0.25 mg/kg, b.w.). The efflux of rhodamine 123 (300 μM), a P-gp fluorescent substrate, significantly increased in TX5-treated everted sacs from the distal portion of the rat ileum, when P-gp activity was evaluated in the presence of TX5 (20 μM), an effect abolished by the P-gp inhibitor verapamil (100 μM). No increases on P-gp expression or activity were found in TX5-treated BBM of the distal ileum and everted distal sacs, respectively, 24 h after TX5 (10 mg/kg, b.w.) administration. In vivo, no differences were found on digoxin portal concentration between control (digoxin 0.025 mg/kg, b.w., intraduodenal) and TX5-treated (digoxin+TX5 20 μM, intraduodenal) rats. The observed discrepancies in digoxin results can be related to differences in TX5 dose administered and used methodologies. Thus, the results show that TX5 activates P-gp at the distal portion of the rat ileum, and, at the higher dose tested (30 mg/kg, b.w.), seems to modulate in vivo the AUC of P-gp substrates.Fil: Rocha-Pereira, Carolina. Universidad de Porto; PortugalFil: Ghanem, Carolina Inés. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Farmacológicas. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Investigaciones Farmacológicas; ArgentinaFil: Silva, Renata. Universidad de Porto; PortugalFil: Casanova, Alfredo G.. Universidad de Salamanca; EspañaFil: Duarte Araújo, Margarida. Universidad de Porto; PortugalFil: Gonçalves Monteiro, Salomé. Universidad de Porto; PortugalFil: Sousa, Emília. Universidad de Porto; PortugalFil: Bastos, Maria de Lourdes. Universidad de Porto; PortugalFil: Remião, Fernando. Universidad de Porto; Portuga

Patient-reported outcomes and experiences assessment in women with breast cancer: Portuguese case study

In 2020, female breast cancer was the most commonly diagnosed cancer worldwide, representing the type of cancer with the highest incidence among women and the second most common cause of cancer death among women in all OECD countries. The conventional measures addressing the burden of breast cancer by measuring mortality, incidence, and survival do not entirely reflect the quality of life and patients' experience when receiving breast cancer care. The main objective of this study is to capture patient-reported outcomes and experiences in women with breast cancer in Portugal using methods developed for international benchmarking purposes, such as the OECD Patient-reported Indicators Surveys. The study included 378 women with breast cancer, with the age distribution being 19.8% aged 15 to 49 years and 80.2% aged 50 years and over. The data collection procedure and analysis followed the "OECD Breast Cancer Patient Reported Outcomes Working Group" protocol, allowing subsequent comparability with data from other OECD member countries. Most women were satisfied with the treatment outcome regarding the shape of their lumpectomy breasts when wearing a bra (96.1%) and with the equal size of both breasts (78.3%). Findings on the WHO QOL-BREF showed that women manifest a lower score in well-being when compared with the general population or populations living with chronic diseases. This study shows the feasibility of implementing and using patient-reported metrics (PROM and PREM) in breast cancer services in Portugal. Measuring PROMs and PREMs from Portuguese women receiving breast cancer care provides insightful evidence of the quality and value of cancer care.info:eu-repo/semantics/publishedVersio

Preclinical pharmacokinetics and biodistribution of anticancer dinuclear Palladium(II)-Spermine Complex (Pd2Spm) in mice

Palladium-based compounds are regarded as potential analogs to platinum anticancer drugs with improved properties. The present study assessed the pharmacokinetics and biodistribution of a dinuclear palladium(II)-spermine chelate (Pd2Spm), which has previously been shown to possess promising in vitro activity against several therapy-resistant cancers. Using inductively coupled plasma-mass spectrometry, the kinetic profiles of palladium/platinum in serum, serum ultrafiltrate and tissues (kidney, liver, brain, heart, lungs, ovaries, adipose tissue and mammary glands) were studied in healthy female Balb/c mice after a single intraperitoneal bolus injection of Pd2Spm (3 mg/kg bw) or cisplatin (3.5 mg/kg bw) between 0.5 and 48 h post-injection. Palladium in serum exhibited biphasic kinetics with a terminal half-life of 20.7 h, while the free palladium in serum ultrafiltrate showed a higher terminal half-life than platinum (35.5 versus 31.5 h). Palladium was distributed throughout most of the tissues except for the brain, with the highest values in the kidney, followed by the liver, lungs, ovaries, adipose tissue and mammary glands. The in vitro cellular accumulation was also evaluated in breast cancer cells, evidencing a passive diffusion as a mechanism of Pd2Spm’s cellular entry. This study reports, for the first time, the favorable pharmacokinetics and biodistribution of Pd2Spm, which may become a promising pharmacological agent for cancer treatmentinfo:eu-repo/semantics/publishedVersio

Pd2Spermine Complex Shows Cancer Selectivity and Efficacy to Inhibit Growth of Triple-Negative Breast Tumors in Mice

Pd2Spm is a dinuclear palladium(II)-spermine chelate with promising anticancer properties against triple-negative breast cancer (TNBC), a breast carcinoma subset with poor prognosis and limited treatment options. The present study evaluated the in vitro and in vivo anticancer effects of Pd2Spm compared to the reference metal-based drug cisplatin. Triple-negative breast cancer MDA-MB-231 cells, non-cancerous MCF-12A breast cells and chorioallantoic membrane (CAM) assay were used for antiproliferative, antimigratory and antiangiogenic studies. For an in vivo efficacy study, female CBA nude mice with subcutaneously implanted MDA-MB-231 breast tumors were treated with Pd2Spm (5 mg/kg/day) or cisplatin (2 mg/kg/day) administered intraperitoneally during 5 consecutive days. Promising selective antiproliferative activity of Pd2Spm was observed in MDA-MB-231 cells (IC50 values of 7.3-8.3 µM), with at least 10-fold lower activity in MCF-12A cells (IC50 values of 89.5-228.9 µM). Pd2Spm inhibited the migration of MDA-MB-231 cells, suppressed angiogenesis in CAM and decreased VEGF secretion from MDA-MB-231 cells with similar potency as cisplatin. Pd2Spm-treated mice showed a significant reduction in tumor growth progression, and tumors evidenced a reduction in the Ki-67 proliferation index and number of mitotic figures, as well as increased DNA damage, similar to cisplatin-treated animals. Encouragingly, systemic toxicity (hematotoxicity and weight loss) observed in cisplatin-treated animals was not observed in Pd2Spm-treated mice. The present study reports, for the first time, promising cancer selectivity, in vivo antitumor activity towards TNBC and a low systemic toxicity of Pd2Spm. Thus, this agent may be viewed as a promising Pd(II) drug candidate for the treatment of this type of low-prognosis neoplasia

Improvements on the traditional method used to produce dried pears in portugal.

In Portugal dried pears are produced from pears of the variety identified as S. Bartolomeu by a traditional open-air solar drying process, that includes the following steps: 1 – skin removing; 2 – a first drying stage in which the pears are exposed to the sun for 5 to 8 days; 3 – a barrelling process in which the pears are covered and left at shadow to increase elasticity; 4 – a pressing operation where the pears change their characteristics from round shape to a flattened one; 5 – a second drying stage, also at the sun, but for only 2 to 3 more days. Although it is a much appreciated food product its production is very small due to the complexity and slowness of the processing method, to the intensive handwork and space requirements and to the shortcomings associated to the natural open-air sun drying. In fact, this process greatly depends on atmospheric conditions, with the variations in temperature influencing quite significantly the drying rates and the rain or night moist delaying or stopping the process, or even rotten the fruits. Moreover, the process is not very hygienic, and during the drying the pears are exposed to dust and can be attacked by ants, rats, bacteria and fungi, and therefore reliable quality standards are difficult to meet. It is important to adapt the traditional drying process, making it a profitable and competitive production method, offering the consumer products of unquestionable quality. To achieve these goals a solar stove was used for the drying, and 4 varieties of pears were tested in order to find alternatives to the traditional variety. The pears of the varieties Amêndoa, Amorim, Carapinheira Branca and S. Bartolomeu (this one is the traditional) were peeled and dried in a solar stove, following the steps of the traditional method, and their water content was evaluated throughout the drying process. The temperature and relative humidity inside the stove were measured hourly. The nutritional value of the pears was evaluated before and after drying for the 4 varieties, as well as their microbial charge. It was possible to conclude from the present work that the use of the solar stove allowed the obtaining of conditions very favourable to drying, with periods of very high temperatures and very low relative humidities, and also enabling to proceed with drying even when the outside conditions would not allow it. It was also concluded that the four varieties have a very similar kinetic behaviour and that the use of the stove did not influence the nutritional value of the pears