Comparação das propriedades de textura de peras submetidas a descasque manual e químico

O objetivo deste trabalho consistiu no estudo de uma forma alternativa de descasque da pêra, o descasque químico, a uma temperatura de 65 ºC, através de dois solventes a diferentes concentrações (hidróxido de sódio (10 % e 18 %) e hidróxido de potássio (8 % e 14%)). Posteriormente estudou-se o seu impacto nas propriedades de textura da pêra, neste caso a variedade Rocha, quando comparado com os frutos descascados manualmente. No caso do descasque químico com hidróxido de potássio este solvente conduziu a uma ligeira diminuição da dureza da pêra mas manteve praticamente inalterado a sua elasticidade e coesividade. O aumento da concentração do solvente de 8 % para 14 % não conduziu a alterações significativas das propriedades de textura da pêra descascada quimicamente. No que se refere ao hidróxido de sódio e para uma concentração de 10 % verificou-se um aumento da dureza, da elasticidade e da coesividade da pêra descascada com o solvente quando comparada com o descasque manual. No entanto, para a concentração de 18 % de hidróxido de sódio as propriedades de textura foram semelhantes às observadas com o descasque manual

Randomized pilot study on the effects of sarcocornia as a salt substitute in arterial blood pressure and vascular function in healthy young adults

Previous studies have shown that excessive salt intake is strongly associated with high blood pressure (HT), vascular dysfunction, and the overall risk of cardiovascular diseases. The aim of this study was to evaluate Sarcocornia effectiveness as a salt substitute, addressing its effect on cardiovascular function in healthy young individuals. Thirty healthy participants, aged 18 to 26 years, were randomized into two groups: the control group (CG) and the intervention group (IG). The IG used Sarcocornia powder as a salt substitute for cooking, and the CG used regular salt, during a period of 1 month. A baseline evaluation was performed before the participants started the intervention phase, and was repeated after a 30-day intervention period. Each evaluation included blood pressure (BP) measurement, carotid-femoral pulse wave velocity (PWV), and carotid pulse wave analysis (PWA), and blood samples were also collected for analysis. Sodium excretion was measured at baseline and after intervention through spot urine collection and analysis, a method suitable for this population but with known limitations. Baseline parameters were similar between groups and were within the normal range. Sodium excretion remained unchanged in the two evaluations in the CG, but significantly decreased after intervention in the IG. The reduction in sodium excretion in the IG was followed by a significant reduction in brachial and aortic systolic (SBP) and diastolic blood pressure (DBP), and also in PWV. No significant changes were observed in the CG in terms of cardiovascular parameters. This preliminary study conveys positive results in favor of Sarcocornia as a dietary substitute for regular salt, providing added evidence of the negative cardiovascular effects of high salt intake in young and healthy adults.info:eu-repo/semantics/publishedVersio

Pregnancy in the mature adult mouse does not alter the proportion of mammary epithelial stem/progenitor cells

Introduction In humans, an early full-term pregnancy reduces lifetime breast cancer risk by up to 50% whereas a later pregnancy (>35 years old) can increase lifetime risk. Several mechanisms have been suggested, including changes in levels of circulating hormones, changes in the way the breast responds to these hormones, changes in gene expression programmes which may alter susceptibility to transformation and changes to mammary stem cell numbers or behaviour. Previous studies have shown that the mammary tissue isolated from both virgin and parous mice has the ability to repopulate a cleared mammary fat pad in transplant experiments. Limited dilution transplant assays have demonstrated that early pregnancy (at 5 weeks of age) reduces stem/progenitor cell numbers in the mouse mammary epithelium by twofold. However, the effects on stem/progenitor cell numbers in the mammary epithelium of a pregnancy in older animals have not yet been tested. Methods Mice were put through a full-term pregnancy at 9 weeks of age, when the mammary epithelium is mature. The total mammary epithelium was purified from parous 7-week post-lactation and age-matched virgin mice and analysed by flow cytometry and limiting dilution cleared fat pad transplants. Results There were no significant differences in the proportions of different mammary epithelial cell populations or numbers of CD24+/Low Sca-1- CD49fHigh cells (stem cell enriched basal mammary epithelial compartment). There was no significant difference in stem/progenitor cell frequency based on limiting dilution transplants between the parous and age-matched virgin epithelium. Conclusions Although differences between parous and virgin mammary epithelium at later time points post lactation or following multiple pregnancies cannot be ruled out, there are no differences in stem/progenitor cell numbers between mammary epithelium isolated from parous animals which were mated at 9 weeks old and virgin animals. However, a recent report has suggested that animals that were mated at 5 weeks old have a twofold reduction in stem/progenitor cell numbers. This is of interest given the association between early, but not late, pregnancy and breast cancer risk reduction in humans. However, a mechanistic connection between stem cell numbers and breast cancer risk remains to be established

Rad54 is required for the normal development of male and female germ cells and contributes to the maintainance of their genome integrity after genotoxic stress

Rad54 is an important factor in the homologous recombination pathway of DNA double-strand break repair. However, Rad54 knockout (KO) mice do not exhibit overt phenotypes at adulthood, even when exposed to radiation. In this study, we show that in Rad54 KO mouse the germline is actually altered. Compared with the wild-type (WT) animals, these mice have less premeiotic germ cells. This germ cell loss is found as early as in E11.5 embryos, suggesting an early failure during mutant primordial germ cells development. Both testicular and ovarian KO germ cells exhibited high radiation sensitivity leading to a long-term gametogenesis defect at adulthood. The KO female germline was particularly affected displaying decreased litter size or sterility. Spermatogenesis recovery after irradiation was slower and incomplete in Rad54 KO mice compared with that of WT mice, suggesting that loss of germ stem cell precursors is not fully compensated along the successive rounds of spermatogenesis. Finally, spermatogenesis recovery after postnatal irradiation is in part regulated by glial-cell-line-derived neurotrophic factor (GDNF) in KO but not in irradiated WT mice, suggesting that Sertoli cell GDNF production is stimulated upon substantial germ cell loss only. Our findings suggest that Rad54 has a key function in maintaining genomic integrity of the developing germ cells

Fancb deficiency impairs hematopoietic stem cell function

Fanconi anemia (FA) is a genetic disorder characterized by bone marrow failure, variable congenital malformations and a predisposition to malignancies. FANCB (also known as FAAP95), is the only X-linked FA gene discovered thus far. In the present study, we investigated hematopoiesis in adult Fancb deficient (Fancb(−/y)) mice and found that Fancb(−/y) mice have decreased hematopoietic stem cell (HSC) quiescence accompanied by reduced progenitor activity in vitro and reduced repopulating capacity in vivo. Like other FA mouse models previously reported, the hematopoietic system of Fancb(−/y) mice is hypersensitive to DNA cross-linking agent mitomycin C (MMC), which induces bone marrow failure in Fancb(−/y) mice. Furthermore, Fancb(−/y) BM exhibits slower recovery kinetics and less tolerance to myelotoxic stress induced by 5-fluorouracil than wild-type littermates. RNA-seq analysis reveals altered expression of genes involved in HSC function and cell cycle regulation in Fancb(−/y) HSC and progenitor cells. Thus, this Fancb(−/y) mouse model provides a novel approach for studying the critical role of the FA pathway not only in germ cell development but also in the maintenance of HSC function