522 research outputs found
Cádmio e a atividade de peroxidase durante a germinação de sementes de feijoeiro
Seeds of common bean seeds cv. Carioca were germinated in the dark in different concentrations of cadmium (1, 2, 5 and 10 mumol L-1) and collected after 24, 48, 72 and 96 hours with the objective of verifying if theperoxidase activity could be used as a biochemical marker of stress induced by cadmium. Alterations in the peroxidase activity (EC 1.11.1.7) were oberved in the cotyledons as well as in roots, as a function of the exhibition time of seeds in different cadmium concentrations. This enzyme can be used as a stress marker caused by cadmium during bean seed germination as an indicative of possible injure of the seeds by this metal.Sementes de feijoeiro cv. Carioca, foram germinadas no escuro em diferentes concentrações de cádmio (1, 2, 5 e 10 mimol L-1) e coletadas após 24, 48 , 72 e 96 horas com o objetivo de verificar se a atividade da peroxidase, poderia ser utilizada como marcador bioquÃmico de estresse promovido pelo cádmio. Observaram-se alterações na atividade especÃfica da peroxidase (EC 1.11.1.7) tanto nos cotilédones como nas raÃzes, em função do tempo de exposição das sementes nas diferentes concentrações de cádmio. A enzima peroxidase (EC 1.11.1.7) pode ser usada como um indicador de estresse causado pelo cádmio durante a germinação de sementes de feijão, indicando possÃveis injúrias causadas nas sementes pelo metal
Estrogens in males: what have we learned in the last 10 years?
This review focuses on the role of estrogen in men, mainly in male reproduction. The continuing increase in data obtained, and recent discoveries in this area will enable a better understanding of male physiology; these, in turn, will have important clinical implications
Effects of dog-assisted therapies on cognitive mnemonic capabilities in people affected by Alzheimer's disease
Alzheimer’s disease (AD) is the most common cause of dementia in humans and, currently, a valid treatment is lacking. Our goal is to demonstrate the importance and benefits of the relationship with companion animals (considered as co-therapists), intended as a means of facilitating social relations and promoting evident wellbeing in AD patients. The study involved 30 randomly chosen patients with Alzheimer’s disease (group T) and three dogs. The group participated in a total of 24 animal-assisted interventions (AAIs) sessions over a span of 12 weeks, using the Mini-Mental State Examination (MMSE), Wellness and Cognitive Ability Questionnaire (Brief Assessment Cognition or BAC), and Alzheimer’s Disease Assessment Scale (ADAS) as assessment tests. A second group (group C), consisting of 10 people with AD, was enrolled as control group and underwent the same assessment tests but did not benefit from the presence of the dogs. Tests were carried out at time T0 (before starting sessions), T1 (end of sessions), and T2 (two months after last session). People belonging to group T achieved an overall improvement in their perceived state of wellbeing, even on a cognitive and mnemonic plane. However, two months after the end of the sessions, the test results in people suffering from AD decreased towards the baseline (T0). The study shows how such progress can be achieved through activities based on the relationship with an animal, as long as the animal is a steady presence in the life of the patient receiving the intervention. Dogs involved in other dog-assisted therapies have been found suitable also for assisting patients with AD
Endothelin-1[1–31], acting as an ETA-receptor selective agonist, stimulates proliferation of cultured rat zona glomerulosa cells
AbstractEndothelin-1 (ET-1)[1–31] is a novel hypertensive peptide that mimics many of the vascular effects of the classic 21 amino acid peptide ET-1[1–21]. However, at variance with ET-1[1–21] that enhances aldosterone secretion from cultured rat zona glomerulosa (ZG) cells by acting via ETB receptors, ET-1[1–31] did not elicit such effect. Both ET-1[1–21] and ET-1[1–31] raised the proliferation rate of cultured ZG cells, the maximal effective concentration being 10−8 M. This effect was blocked by the ETA-receptor antagonist BQ-123 and unaffected by the ETB-receptor antagonist BQ-788. Quantitative autoradiography showed that ET-1[1–21] displaced both [125I]PD-151242 binding to ETA receptors and [125I]BQ-3020 binding to ETB receptors in both rat ZG and adrenal medulla, while ET-1[1–31] displaced only [125I]BQ-3020 binding. The tyrosine kinase (TK) inhibitor tyrphostin-23 and the p42/p44 mitogen-activated protein kinase (MAPK) inhibitor PD-98059 abolished the proliferogenic effect of ET-1[1–31], while the protein kinase-C (PKC) inhibitor calphostin-C significantly reduced it. ET-1[1–31] (10−8 M) stimulated TK and MAPK activity of dispersed ZG cells, an effect that was blocked by BQ-123. The stimulatory action of ET-1[1–31] on TK activity was annulled by tyrphostin-23, while that on MAPK activity was reduced by calphostin-C and abolished by either tyrphostin-23 and PD-98059. These data suggest that ET-1[1–31] is a selective agonist of the ETA-receptor subtype, and enhances proliferation of cultured rat ZG cells through the PKC- and TK-dependent activation of p42/p44 MAPK cascade
A Substrate-induced Switch in the Reaction Mechanism of a Thermophilic Esterase KINETIC EVIDENCES AND STRUCTURAL BASIS
The reaction mechanism of the esterase 2 (EST2) from Alicyclobacillus acidocaldarius was studied at the kinetic and structural level to shed light on the mechanism of activity and substrate specificity increase previously observed in its double mutant M211S/R215L. In particular, the values of kinetic constants (k1, k(-1), k2, and k3) along with activation energies (E1, E(-1), E2, and E3) were measured for wild type and mutant enzyme. The previously suggested substrate-induced switch in the reaction mechanism from kcat=k3 with a short acyl chain substrate (p-nitrophenyl hexanoate) to kcat=k2 with a long acyl chain substrate (p-nitrophenyl dodecanoate) was validated. The inhibition afforded by an irreversible inhibitor (1-hexadecanesulfonyl chloride), structurally related to p-nitrophenyl dodecanoate, was studied by kinetic analysis. Moreover the three-dimensional structure of the double mutant bound to this inhibitor was determined, providing essential information on the enzyme mechanism. In fact, structural analysis explained the observed substrate-induced switch because of an inversion in the binding mode of the long acyl chain derivatives with respect to the acyl- and alcohol-binding sites
Microgravity Promotes Differentiation and Meiotic Entry of Postnatal Mouse Male Germ Cells
A critical step of spermatogenesis is the entry of mitotic spermatogonia into meiosis. Progresses on these topics are hampered by the lack of an in vitro culture system allowing mouse spermatogonia differentiation and entry into meiosis. Previous studies have shown that mouse pachytene spermatocytes cultured in simulated microgravity (SM) undergo a spontaneous meiotic progression. Here we report that mouse mitotic spermatogonia cultured under SM with a rotary cell culture system (RCCS) enter into meiosis in the absence of any added exogenous factor or contact with somatic cells. We found that isolated Kit-positive spermatogonia under the RCCS condition enter into the prophase of the first meiotic division (leptotene stage), as monitored by chromosomal organization of the synaptonemal complex 3 protein (Scp3) and up-regulation of several pro-meiotic genes. SM was found to activate the phosphatidyl inositol 3 kinase (PI3K) pathway and to induce in Kit-positive spermatogonia the last round of DNA replication, typical of the preleptotene stage. A PI3K inhibitor abolished Scp3 induction and meiotic entry stimulated by RCCS conditions. A positive effect of SM on germ cell differentiation was also observed in undifferentiated (Kit-negative) spermatogonia, in which RCCS conditions stimulate the expression of Kit and Stra8. In conclusion, SM is an artificial environmental condition which promotes postnatal male germ cell differentiation and might provide a tool to study the molecular mechanisms underlying the switch from mitosis to meiosis in mammals
Attenuated polyposis of the large bowel: a morphologic and molecular approach
Attenuated polyposis could be defined as a variant of familial adenomatous polyposis (FAP) in which synchronous polyps of the large bowel range between 10 and 99. We analysed all cases of attenuated polyposis observed over the last 30 years with the objectives: (A) to classify the disease according to different type and proportion of polyps; (B) To ascertain the contribution of APC and MutYH genes; (C) to discover features which could arise the suspicion of mutations; (D) To obtain indications for management and follow-up. 84 individuals in 82 families were studied. Polyps were classified into four groups as adenoma, hyperplastic, other serrated lesions or others; APC and MutYH mutations were assessed. Mean age at diagnosis was 54 ± 14 years in men and 48 ± 13 in women (P = 0.005). Polyps were more numerous in women (37 ± 26 vs 29 ± 22). Sixty % of patients underwent bowel resection, mainly for cancer; the remaining were managed through endoscopy. A total of 2586 polyps were detected at diagnostic endoscopy: 2026 (80 %) were removed and analysed. Adenomas were diagnosed in 1445 (70 %), hyperplastic polyps in 541 (26 %), other serrated lesions in 61 (2.9 %). Adenomas and hyperplastic lesions were detected in the majority of patients. In 68 patients (81 %) in whom studies were executed, APC mutations were found in 8 and MutYH mutations in 10. Genetic variants were more frequent in women (12 vs 6, P = 0.039). Taking into consideration the prevalent (>50 %) histology and presence of mutations, patients could be subdivided into four groups: (1) APC mutated polyposis (AFAP), when adenomas were >50 % and APC mutations detected (no. 8, 10 %); (2) MutYH mutated polyposis (MAP), adenomas >50 % and biallelic MutYH mutations (no. 10, 12 %); (1) attenuated polyposis without detectable mutations, prevalence of adenomas, 48 cases (57 %); (1) hyperplastic-serrated polyposis, with prevalence (>50 %) of hyperplastic/other serrated lesions and no constitutional mutation (no. 18, 21 %). Aggregation of tumors, cancer in probands, distribution of polyps and other clinical characteristics showed no difference among the four groups. In conclusions, AFAP and MAP, the polyposis labeled by constitutional mutations, represented about 25 % of all attenuated polyposis. Mutation-associated cases showed an earlier age of onset of polyps and were more frequent in the female sex
Wound Healing Activity of Nanoclay/Spring Water Hydrogels
Background: hydrogels prepared with natural inorganic excipients and spring waters are commonly used in medical hydrology. Design of these clay-based formulations continues to be a field scarcely addressed. Safety and wound healing properties of different fibrous nanoclay/spring water hydrogels were addressed. Methods: in vitro biocompatibility, by means of MTT assay, and wound healing properties were studied. Confocal Laser Scanning Microscopy was used to study the morphology of fibroblasts during the wound healing process. Results: all the ingredients demonstrated to be biocompatible towards fibroblasts. Particularly, the formulation of nanoclays as hydrogels improved biocompatibility with respect to powder samples at the same concentration. Spring waters and hydrogels were even able to promote in vitro fibroblasts motility and, therefore, accelerate wound healing with respect to the control. Conclusion: fibrous nanoclay/spring water hydrogels proved to be skin-biocompatible and to possess a high potential as wound healing formulations. Moreover, these results open new prospects for these ingredients to be used in new therapeutic or cosmetic formulations.This research was funded by Ministerio de Ciencia e Innovación, CGL2016–80833-R; ConsejerÃa de EconomÃa, Innovación, Ciencia y Empleo, Junta de AndalucÃa, P18-RT-3786 and Ministerio de Educación, Cultura y Deporte, FPU15/01577.Peer reviewe
Effects of boiling and oil or vinegar on pickled jurubeba (Solanum paniculatum L.) fruit
Jurubeba fruit, raw and thermally processed for different periods of time, were preserved in soybean oil or vinegar and evaluated for physical characteristics, phytochemicals, antioxidant capacity and polyamines. The loss of green color in many vegetables after cooking is a frequent problem that affects the quality of pickled foods, and chlorophyll content is a relevant parameter to assess the quality. Data showed that a 20 min cooking treatment maintained the best fruit quality and no change in the chlorophyll content occurred. The thermal processing caused no increase in the carotenoid and flavonoid content as compared to the raw fruits, but caused an increase in the phenol content. At a cooking time of about 10 min, the antioxidant capacity increased. Cooking time did not cause significant differences in the content of isoorientin, rutin and caffeic acid. Spermine and spermidine contents were lower after 20 min of boiling. Jurubeba that was preserved in vinegar showed a lower pH and putrescine level, regardless of the cooking time used, whereas the use of oil caused an increase in carotenoids and antioxidant capacity.Key words: Thermal processing, antioxidants, polyamines, phytochemicals, Solanaceae
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