60 research outputs found
Fighting bisphenol a-induced male infertility: The power of antioxidants
Bisphenol A (BPA), a well-known endocrine disruptor present in epoxy resins and poly-carbonate plastics, negatively disturbs the male reproductive system affecting male fertility. In vivo studies showed that BPA exposure has deleterious effects on spermatogenesis by disturbing the hypothalamic–pituitary–gonadal axis and inducing oxidative stress in testis. This compound seems to disrupt hormone signalling even at low concentrations, modifying the levels of inhibin B, oestradiol, and testosterone. The adverse effects on seminal parameters are mainly supported by studies based on urinary BPA concentration, showing a negative association between BPA levels and sperm concentration, motility, and sperm DNA damage. Recent studies explored potential approaches to treat or prevent BPA-induced testicular toxicity and male infertility. Since the effect of BPA on testicular cells and spermatozoa is associated with an increased production of reactive oxygen species, most of the pharmacological approaches are based on the use of natural or synthetic antioxidants. In this review, we briefly describe the effects of BPA on male reproductive health and discuss the use of antioxidants to prevent or revert the BPA-induced toxicity and infertility in men.This research was funded by Institute for Biomedicine—iBiMED, grant number UID/BIM/04501/2020 and by individual grant from FCT of the Portuguese Ministry of Science and Higher Education to J.S. (SFRH/BD/136896/2018)
Tariff systems for fleets of vehicles: a study on the portfolio of Fidelidade
In Portugal, insurance policies for fleets of vehicles are, in general, similar to policies for individual vehicles. Such is the case of the insurance company at hand. The experience rating system is practically the same as in individual motor insurance and is applied independently to each vehicle, thus having no effect on the premium paid by other vehicles in the fleet. This experience rating system is inefficient since it ignores the potential fleet-specific risks in the a posteriori tariff. We considered two credibility-based experience rating schemes proposed by Desjardins, Dionne and Pinquet in 2001. One is based on the claims numbers at fleet level and the other is based on the claims numbers at vehicle level. We applied both models in order to calculate experience rating coefficients for the vehicles in the portfolio of fleets of the insurer. We propose different estimators for the structure parameters of the model, which in our opinion handle better the heterogeneity of the time exposures of our data set. Keywords.info:eu-repo/semantics/publishedVersio
Multi-method Active Learning Approach: improving the educational experience in Pharmaceutical Drug Development
Improve educational experience, teaching effectiveness and learning outcomes remains one of the major educational challenges nowadays. Accordingly, our aim is to determine the effect of organizing and teaching the Pharmaceutical Drug Development unit using a Multi-method Active Learning Approach, MALA, as a novel teaching/learning strategy. MALA involved several different activities about pharmaceutical legislation, medicines production and validation process, Common Technical Document, and others, and the evaluation of this active learning approach was made in two ways: students’ performance (grades), and students’ evaluation regarding the curricular unit and the teachers’ performance. Results revealed two main important aspects of the implementation of MALA: (i) the implementation of MALA showed high rates of students’ satisfaction regarding the curricular unit and teachers’ performance; (ii) student’s performance (grades) were very high, revealing excellent teaching/ learning results. In conclusion, the present study fostered the concept that the MALA- learning approach should contribute to knowledge- enhancing in the pharmaceutical practice and could encourage integration of the students´ learning skills in the future career, thus stimulating the flexibility in learning.publishe
Palliative splenic irradiation for symptomatic splenomegaly in non-Hodgkin lymphoma
INTRODUCTION AND AIMS:
Splenic marginal zone lymphoma, an uncommon subtype of non-Hodgkin lymphoma (NHL), is usually present with symptomatic splenomegaly. Although splenectomy has long been considered the first-line therapy in symptomatic or cytopenic patients, it can lead to significant morbidity and mortality. Splenic irradiation is an option for patients who have a poor response to systemic therapy and/or are not surgical candidates. In this paper, we present a case report of a patient who received splenic radiotherapy for symptomatic splenomegaly.
METHODS:
An 85-year-old Caucasian man with a 4 year history of low-grade NHL presented with progressive pancytopenia, significant weight loss and symptomatic splenomegaly (abdominal discomfort, sense of fullness and limitation of mobility due to spleen size). The patient refused splenectomy and, in December 2017, was referred to palliative splenic radiotherapy. He was initially treated with five fractions of one Grey (Gy) in order to evaluate clinical and haematology response. After that, 1.5 Gy daily, 5 days a week for 3 weeks. 3D conformal radiotherapy, multiple fields and mixed energy (6 and 15 Mv) were used.
RESULTS:
Radiotherapy allowed significant splenic reduction to almost half the size, resolving abdominal discomfort and improving quality of life. There was no decline of haemoglobin, leukocytes and platelet counts; in fact, there was a marginal increase.
CONCLUSION:
Palliative splenic irradiation was well tolerated confirming that it is a safe treatment option for palliation of symptomatic splenomegaly. Thereby, splenic irradiation should be strongly considered in the management of symptomatic splenomegaly, for selected patients who are refractory to or unsuitable for other options or when the patient refuses other treatments.info:eu-repo/semantics/publishedVersio
A ruthenium(II)-trithiacyclononane curcuminate complex: synthesis, characterization, DNA-interaction, and cytotoxic activity
The coordination of ruthenium(II) complexes to anionic oxygen-based donors are very rare. This study describes a simple, one-pot method for obtaining [ruthenium(II)(trithiacyclononane)(curcumin)(S-DMSO)]Cl (1) in 37% yield. The structural characterization of complex 1 by elemental analysis, FT-IR, 1-D and 2-D NMR, ESI+-MS as well as UV–vis and fluorescence spectroscopies are presented. The DNA-melting temperature (Tm) assay shows that salmon sperm DNA (smDNA) in the presence of complex 1 has a higher melting temperature, with ΔTm = 7.4 °C, while in the presence of curcumin the melting temperature remains unaltered. The in vitro cytotoxic activities of curcumin and complex 1 were investigated using the tumor human prostate cell line, PC-3, and the healthy cell line, PNT-2. Complex 1 is innocuous toward normal prostate epithelial cells and, whereas curcumin is toxic, with inhibition rates of ca. 35 and 65% at 50 and 80 μM, respectively. On the tumor cell line PC-3, complex 1 did not cause viability changes, whereas curcumin exhibited dose-dependent inhibition, with ca. 73% inhibition at the highest concentration tested, i.e. 80 μM. This study suggests that coordination with the trithiacyclononane ruthenium(II) scaffold stabilizes the photochemical properties of curcumin and strongly changes its biologic activity.publishe
An insight on the role of photosensitizer nanocarriers for Photodynamic Therapy
Photodynamic therapy (PDT) is a modality of cancer treatment in which tumor cells are destroyed by reactive oxygen species (ROS) produced by photosensitizers following its activation with visible or near infrared light. The PDT success is dependent on different factors namely on the efficiency of the photosensitizer deliver and targeting ability. In this review a special attention will be given to the role of some drug delivery systems to improve the efficiency of tetrapyrrolic photosensitizers to this type of treatment.publishe
Rat prostate: practical tips for ultrasonographic monitoring
Background: Prostate is the largest accessory gland of the male reproductive tract. The prostate of men over 40 years- old is frequently affected by several pathologies, like benign prostate hyperplasia and cancer. Rats have been used as model to study prostate cancer. This study intended to address the usefulness of ultrasonography for rat prostate monitoring. Materials and Methods: Eight male Wistar Unilever rats were acquired from Charles River Laboratories and main- tained under controlled conditions of temperature, humidity, air system filtration and light/dark cycle. The prostate was evaluated by ultrasonography in awake animals. The animals were restrained by a researcher and placed in supine position. The skin of the inguinal region was shaved using a machine clipper (AESCULAP® GT420 Isis, USA). A real-time scan- ner (Logic P6®, GE, USA) and a 12 MHz linear transducer were used. Acoustic gel (Parker Laboratories Inc., USA) was applied. A complete transverse scan using B mode was per- formed from the cranial to the caudal region of the prostate, and a sagittal scan was performed moving the probe from the right to the left side. Procedures were approved by the Portuguese Ethics Committee (no.021326).
Results: Prostate was easily evaluated by ultrasonography in all animals. In the transverse scan, the urinary bladder presents as a round to oval shape filled with urine (anechoic structure) and the prostate lobes were visible around it. The ventral prostate lobes appear as hypoechoic elongated struc- tures (one right and one left) with a hyperechoic capsule, placed ventrally to the urinary bladder. In this scan, the dorsal prostate was observed close to the urinary bladder neck, as a round hypoechoic structure with a hyperechoic capsule, dor- sally to the urinary bladder. In the sagittal scan, the urinary bladder was observed as an elongated structure filled with urine (anechoic content). The ventral prostate lobes were occasionally observed ventrally to the neck of the urinary bladder, as previously described. The dorsal prostate was ob- served dorsally to the neck of the urinary bladder, presenting as a round to elongated shape, with a hypoechoic appearance and a hyperechoic capsule.Conclusions: The ultrasonography is a non-invasive and ac- cessible tool for prostate monitoring in the rat model. Acknowledgments: This work was supported by European Investment Funds by FEDER/ COMPETE/POCI - Operational Competitiveness and Internationalization Program and National Funds by FCT - Portuguese Foundation for Science and Technology, under the projects Project RUNawayPCa (POCI-01-0145-FEDER-016728 and PTDC/DTP-DES/6077/2014), UIDB/04033/2020, UIDB/ CVT/00772/2020 and UIDB/50006/2020 (LAQV)
Anatomy and imaging of rat prostate: practical monitoring in experimental cancer-induced protocols
The rat has been frequently used as a model to study several human diseases, including cancer. In many research protocols using cancer models, researchers find it difficult to perform several of the most commonly used techniques and to compare their results. Although the protocols for the study of carcinogenesis are based on the macroscopic and microscopic anatomy of organs, few studies focus on the use of imaging. The use of imaging modalities to monitor the development of cancer avoids the need for intermediate sacrifice to assess the status of induced lesions, thus reducing the number of animals used in experiments. Our work intends to provide a complete and systematic overview of rat prostate anatomy and imaging, facilitating the monitoring of prostate cancer development through different imaging modalities, such as ultrasonography, computed tomography (CT) and magnetic resonance imaging (MRI).publishe
The nuclear envelope protein, LAP1B, is a novel protein phosphatase 1 substrate
Protein phosphatase 1 (PP1) binding proteins are quintessential regulators, determining substrate specificity and defining subcellular localization and activity of the latter. Here, we describe a novel PP1 binding protein, the nuclear membrane protein lamina associated polypeptide 1B (LAP1B), which interacts with the DYT1 dystonia protein torsinA. The PP1 binding domain in LAP1B was here identified as the REVRF motif at amino acids 55-59. The LAP1B:PP1 complex can be immunoprecipitated from cells in culture and rat cortex and the complex was further validated by yeast co-transformations and blot overlay assays. PP1, which is enriched in the nucleus, binds to the N-terminal nuclear domain of LAP1B, as shown by immunocolocalization and domain specific binding studies. PP1 dephosphorylates LAP1B, confirming the physiological relevance of this interaction. These findings place PP1 at a key position to participate in the pathogenesis of DYT1 dystonia and related nuclear envelope-based diseases.publishe
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