310 research outputs found
Derivation of an Abelian effective model for instanton chains in 3D Yang-Mills theory
In this work, we derive a recently proposed Abelian model to describe the
interaction of correlated monopoles, center vortices, and dual fields in three
dimensional SU(2) Yang-Mills theory. Following recent polymer techniques,
special care is taken to obtain the end-to-end probability for a single
interacting center vortex, which constitutes a key ingredient to represent the
ensemble integration.Comment: 18 pages, LaTe
Pancreatic lesions and metabolic aggravation are prevented by low doses of sitagliptin in a rat model of type 2 diabetes
Introduction: The management of type 2 diabetes is designed to reduce disease-related complications and improve long-term outcomes. Inhibition of dipeptidyl peptidase-4 (DPP-4) activity by sitagliptin has been shown to improve glycaemic control in patients with type 2 diabetes Mellitus (T2DM) by prolonging the actions of incretin hormones, but the real impact of low-dose sitagliptin treatment on cardiometabolic risk factors and pancreatic lesions is almost unknown. This study aimed to evaluate the effects of low doses of sitagliptin on cardiovascular risk factors and histological pancreas parameters in Zucker Diabetic Fatty rats (ZDF (fa/fa)) an animal model of T2DM.
Materials and Methods: Twenty weeks old diabetic obese (fa/fa) ZDF male rats were treated with vehicle or sitagliptin (10 mg/kg BW/day) during 6 weeks (n=8 each). The following parameters were assessed: glycaemia, HbA1c, insulin, lipidic profile; blood pressure. Specimens for pancreatic histopathology were stained with haematoxylin-eosin and periodic-acid-Shiff, examined by light microscopy. Endocrine and exocrine pancreas was evaluated semiquantitatively concerning inflammatory infiltrate, fibrosis, vacuolization and congestion, and scored from 0 (absent) to 3 (severe and extensive damage).
Results: Sitagliptin in diabetic obese ZDF rats promoted a positive effect on dysglycaemia, dyslipidaemia and prevented the increase of blood pressure. Endocrine and exocrine pancreas presented a reduction/amelioration of fibrosis severity, inflammatory infiltrate, intra-islet vacuolation, and congestion vs the vehicle-treated diabetic rats.
Conclusion: Simultaneous improvement of a sustainable glycaemic profile and of pancreatic histopathological lesions supports the favorable cardiovascular risk profile and may prove beneficial in decreasing long-term complications of T2DM.The authors are very grateful to the support of Fundação Merck Sharp & Dohm
Anti-inflammatory, anti-proliferative and antioxidant profiles of selective cyclooxygenase-2 inhibition as chemoprevention for rat bladder carcinogenesis
PURPOSE: To evaluate the efficacy of a selective cyclooxygenase-2 (COX-2) inhibitor in rat bladder cancer chemoprevention, as well as to assess the relevance of inflammation, proliferation and oxidative stress in tumor growth and in its prevention.
RESULTS: The main findings were: (I) the incidence of carcinoma was: control: 0% (0/8); BBN: 65% (13/20); CEL: 0% (0/8) and BBN + CEL: 12.5% (1/8); (II) the mean tumor volume per rat with tumor and per tumor were significantly lower in the BBN + CEL group (21.2 and 5.3 +/- 0.4 mm(3)) vs. BBN (138.5 +/- 7.5 and 112.5 +/- 6.4 mm(3)); (III) the incidence of pre-neoplasic (hyperplasia and dysplasia) and neoplasic (papillary tumors and carcinoma in situ-CIS) lesions were notoriously reduced in the CEL + BBN treatment; (IV) CEL significantly reduced serum TGFbeta1 and CRP and increase TNFalpha and IL-1beta (p < 0.001); (V) CEL reduced MDA formation in serum (p < 0.001) and liver (p < 0.05) and also showed a trend to reduction in kidney.
METHODS: Drug treatments were performed during the first 8 w, followed by 12 w for tumor expression/prevention, in the following groups: control-vehicle; carcinogen-0.05% of N-butyl-N-(4-hydroxybutyl)nitrosamine (BBN); celecoxib (CEL)-10 mg/kg/day and preventive CEL + BBN. The bladders were analyzed for number and volume of tumor and nature of urothelium lesions. Serum was assessed for markers of inflammation, proliferation and redox status.
CONCLUSIONS: Celecoxib has demonstrated an outstanding inhibitory effect on bladder cancer chemoprevention, which might be due to its expected anti-inflammatory actions, as well as by anti-proliferatory and antioxidant actions. This data supports a pivotal role of cancer chemoprevention strategies based on COX-2 inhibition
The Coexistence of Dual Form of Malnutrition among Portuguese Institutionalized Elderly People
In the present study we evaluated the nutritional status of 214 institutionalized elderly residents of both genders, aged 65 years and older of 11 care homes located in the district of Viseu (center of Portugal). The evaluation was based on anthropometric measurements and the Mini Nutritional Assessment (MNA) score. The mean age of the subjects was 82.3 ± 6.1 years-old. Most of the elderly residents were female (72.0%). The majority had 4 years of formal education (51.9%) and was widowed (74.3%) or married (14.0%). Men presented a mean age of 81.2±8.5 years-old, weight 69.3±14.5 kg and BMI 25.33±6.5 kg/m2. In women, the mean age was 84.5±8.2 years-old, weight 61.2±14.7 kg and BMI 27.43±5.6 kg/m2. The evaluation of the nutritional status using the MNA score showed that 24.0% of the residents show a risk of undernutrition and 76.0% of them were well nourished. There was a high prevalence of obese (24.8%) and overweight residents (33.2%) according to the BMI. 7.5% were considered underweight. We also found that according to their waist circumference measurements 88.3% of the residents were at risk for cardiovascular disease (CVD) and 64.0% of them presented very high risk for CVD (WC≥88 cm for women and WC ≥102 cm for men). The present study revealed the coexistence of a dual form of malnutrition (undernourished and overweight) among the institutionalized Portuguese concomitantly with an excess of abdominal adiposity. The high prevalence of residents at high risk for CVD should not be overlooked. Given the vulnerability of the group of institutionalized elderly, our study highlights the importance of the classification of nutritional status based on both instruments: the BMI and the MNA
Estudo comparativo das castas tintas nobres do Dão: Touriga Nacional, Jaen, Tinta Roriz e Alfrocheiro
Dissertação de Mestrado em Qualidade e Tecnologia AlimentarOs vinhos DOC (Denominação de Origem Controlada)Dão, são reconhecidos pelos consumidores e pela crÃtica, como vinhos de excelência, fruto da sua tipicidade e qualidade invulgares. Sendo as castas nobres do Dão a Touriga Nacional, o Jaen, a Tinta Roriz e o Alfrocheiro considerámos pertinente o estudo das caracterÃsticas sensoriais e fÃsico-quÃmicas de vinhos monocasta produzidos a partir das referidas castas da Região Demarcada do Dão (RDD). Para prossecução desse objectivo dividiu-se o presente trabalho em duas partes distintas. Numa primeira parte foi realizado um levantamento dos dados documentados existentes referentes à região, nomeadamente sobre os vestÃgios históricos da produção de vinho na RDD; referindo-se ainda em detalhe a criação da Região Demarcada do Dão (origens, regulamentação, demarcação), é feita de igual modo uma caracterização do seu património vitÃcola, a evolução, regulamentação e caracterização das castas aptas à produção de 'Dão Nobre', bem como os principais estudos encontrados sobre a caracterização dos vinhos produzidos na Região Demarcada do Dão entre 1953 a 2012. A segunda parte da dissertação é constituÃda pelo trabalho experimental, nela se caracteriza o material em estudo (vinhos tintos mono-castas colheita de 2010 Touriga Nacional, Jaen, Tinta Roriz e Alfrocheiro Preto), referem-se as metodologias utilizadas na análise sensorial e fÃsico-quÃmica, os resultados obtidos e as principais conclusões. Para os parâmetros sensoriais e fÃsico-quÃmicos avaliados os resultados obtidos evidenciaram uma clara inferioridade dos vinhos produzidos a partir da casta Alfrocheiro. Relativamente aos vinhos de Jaen e Tinta Roriz apresentam caracterÃsticas muito semelhantes entre si e não mostraraam, para a maior parte dos parâmetros avaliados, diferenças estatÃsticamente significativas quando comparados com os Touriga Nacional. Foram os vinhos produzidos a partir da Touriga Nacional os que se destacaram em todas as análises efetuadas. Os resultados obtidos quer ao nÃvel da prova sensorial quer nas análises fÃsico-quÃmicas permitem-nos afirmar que a Touriga Nacional, o Jaen e a Tinta Roriz são castas bem adaptadas a condições edafo-climáticas da RDD, com capacidade de ao nÃvel mono-varietal originar vinhos de qualidade e levantam alguma discussão sobre a denominação nobre para a casta Alfrocheiro.ABSTRACT:The wines DOC (Denomination of Controlled Origin) Dão have been recognized by consumers and critics as excellent wines. This results of their unusual characteristics and quality. The species Touriga Nacional, Jaen, Tinta Roriz and Alfrocheiro are the noble varieties demarcated region of Dão (RDD). Thus we considered relevant the study of sensory characteristics and physicochemical properties of single variety wines produced from the grapes of those noble species. In order to achieve that purpose we divided the present work into two distinct parts. In the first part we review the historical traces of wine production in RDD. We detailed the creation of the demarcated region of Dão (origins, regulation, demarcation), as well as the description vineyard tradition, evolution, regulation. We also detailed the different vineard varieties suitable for the production of "Dão Nobre", as well as the major studies found on the characterization of wines produced in the RDD between the end of the XX century and the beginning of the XXI century. The second part of the present work describe the experimental work. A presentation of the material and methods used, the obtained results and the discussion of those results. Finally the conclusion and the major findings of the work. For the physical chemical and sensory parameters evaluated results showed a clear inferiority of the wines produced from the grape variety Alfrocheiro. The wines Jaen and Tinta Roriz have very similar characteristics and do not shown statiscally significant differences, when compared with Touriga Nacional. The wines produced from Touriga Nacional have excelled in every analysis. The obtained results in sensorial and in the physicochemical analyzes allow to affirm that the Touriga Nacional, Jaen and Tinta Roriz are vineyards well adapted to soil and climate conditions of the RDD and with ability to produce excellent 'noble' mono-varietal wine. The inclusion of the Alfrocheiro as noble variety deserves further discussion
Acta da reunião da Assembleia Geral da Sociedade Martins Sarmento realizada em sessão ordinária no dia 15 de Abril de 1988.
97-98 Jan.-Dez. 1987-1988, p. 416
Effect of recombinant human erythropoietin in a rat model of moderate chronic renal failure – focus on inflammation, oxidative Stress and function/renoprotection
Background/Aims: Chronic renal failure (CRF) patients develop anaemia, thus promoting cardiovascular complications, which seems to be favoured by the low kidney erythropoietin (EPO) production. The renal insufficiency
degree might determine the moment to start recombinant human EPO (rhEPO) therapy. It has been attributed important
non-hematopoietic effects to rhEPO, which might underlie cardio and renoprotection. This work aimed to evaluate the effect of rhEPO in a rat model of moderate CRF, focusing on inflammation, oxidative stress and function/renoprotection.
Methods: Four groups (n=7) of male Wistar rats were evaluated during a 15 week follow-up period: control (without
treatment); rhEPO (50 IU/Kg/wk Recormon®); CRF and CRF+rhEPO. Blood samples were collected at the beginning and
3, 9 and 12 weeks after 3/4 nephrectomy, in order to evaluate: renal function, haematological parameters, iron metabolism
and serum proliferative (TGF-B1), inflammatory (TNF-a, CRP, IL-2 and IL-1B) and redox status (MDA, TAS and 3-NT)
markers. Kidney gene expression of Il2, Vegf, Nos2 and Nos3 were assessed by real-time PCR. Blood pressure, heart rate
and tissues trophy indexes were also estimated.
Results: Our data are consistent with a sustained moderate degree of CRF with development of moderate and corrected
anaemia and hypertension. The remnant kidney showed a proliferative profile, with increased mass (hypertrophism),
upregulated tissue Vegf gene expression, accompanied by increased levels of serum TGF-B1. Serum 3-NT was augmented, suggesting oxidative stress, which was accompanied by a trend to higher kidney Nos gene expression of both isoforms. rhEPO treatment was able to partially attenuate renal function markers, totally correct anaemia, also
demonstrating a proliferative and antioxidant action, suggesting renoprotection.
Conclusion: This study suggests that rhEPO therapy might be recommended in moderate CRF stages in order to efficiently correct not only the anaemia but also the underlying deleterious mechanisms, due to a proliferative and antioxidant action on the remnant kidney.info:eu-repo/semantics/publishedVersio
Erythropoietin doping as cause of sudden death in athletes: an experimental study
Aims: To evaluate the cardiovascular (CV) effects of rhEPO treatment in rats under
chronic aerobic exercise and to assess the probable cause of sudden death in one rat.
Protocol: Male Wistar rats: control - sedentary; rhEPO - 50 IU/Kg/3xwk; swimming
(EX) -1 hr, 3x/wk; EX+EPO. Hematology, catecholamines and serotonin, redox status
and inflammation, were assessed. One rat of EX+EPO group suffered a sudden death
episode.
Results: rhEPO treatment in trained rats promoted several markers of increased CV risk.
The sudden death rat tissues presented: lungs without signs of drowning; brain with
vascular congestion; LV hypertrpphy and deregulations of cardiac fibers, together with
a "cardiac liver", suggesting the hypothesis of heart failure as cause of death.
Conclusion: The sudden death of a EX+EPO rat, due to a cardiac episode, together
with the increased CV risk profile, strongly suggest a high life risk associated to the
continuous rhEPO doping. The anatomo-pathological studies were determinant to
establish the cause of death
Hemorheological, biochemical and cardiovascular characterization of a rat model of moderate chronic kidney disease
Chronic kidney disease (CKD) is a major public health problem throughout the world. The major outcomes include a rapid progression, with development of anaemia and serious complications, namely thromboembol
ic and cardiovascular events. The pathophysiological alterations depend on the CKD degree, which will also determine the moment to initiate hemodialysis and recombinant erythropoietin (rhEPO) therapies Thus, the cardio-renal complication might be better prevented or delayed if CKD patients are earlier identified and treated for the associated anaemia, which will depend on a better characterization of moderate stages of CKD. This study aimed to characterization an animal of model of moderate CKD induced by partial (%) nephrectomy, by evaluating hemorheological, biochemical and cardiovascular profiles. Blood samples from control and CKD rats were collected at 0, 3, 9 and 15 weeks in order to evaluate: renal function, hemorheological parameters, iron metabolism, blood lipids, peripheral sympathetic and serotonergic systems, redox state and inflammatory markers. BP, tissues uophism indexes and kidney histomorphology were also assessed. Our data is consistent with a sustained moderate degree of CKD with a quickly compensated modest anaemia, though presenting iron metabolism disturbances. Despite the reasonable degree of functionality of the remnant kidney, as suggested by the anaemia correction and by the kidney hypertrophy, several important cardiovascular modifications were developed. Our model presented hypertension, dyslipidaemia, erythropoietic disturbances, sympathetic activation and oxidative stress. This model might be a good tool to study the cellular/molecularmechanisms underlying moderate stages of CKD and to evaluate the therapeutics efficacy for prevention, treatment/correction of cardiorenal anaemia syndromes and complications in early stages.info:eu-repo/semantics/publishedVersio
Efeitos hemorreológicos e cardiovasculares da eritropoietina num modelo de rato em exercÃcio fÃsico sob a acção de drogas
Recombinant human erythropoietin
(rhEPO) has been therapeutically
used for correction of anaemia. However,
due to the increase in circulating
red blood cells (RBCs) it promotes,
thus increasing oxygen delivery to
muscles and improving performance
in sport, it has been also illegally used
as sports doping. Besides the well
known increase of hematocrit and
blood viscosity; which might cause
serious complications for the athletes,
other disturbances could occur, whose
mechanisms remain to be fully elucidated.
This study aimed to evaluate
the hemorheological and cardiovascular
effects of administration of
rhEPO to rats under chronic aerobic
exercise. A ten week-protocol was
performed in four male Wistar rat
groups: control — sedentary; rhEPO
— 50 IV/kg, 3 times/wk; exercised
(EX) — swimming for 1 hr, 3 times/
wk; EX+rhEPO. rhEPO in trained
rats promoted erythrocyte count increase,
hypertension, heart hypertro-phy, sympathetic and serotonergic
overactivation, as well as a trend to
increased oxidative stress. In conclusion,
rhEPO doping in rats under
chronic exercise promotes not only
the expected increased hematocrit,
but also other serious deleterious cardiovascular
and thromboembolic
modifications, including live risk,
which might be known and assumed
by all sports authorities, including
athletes and their physicians.info:eu-repo/semantics/publishedVersio
- …