Advances in knowledge of Manihot (Euphorbiaceae) from Brazil.

Herbarium-based studies and extensive field work revealed the existence of a new species in the genus Manihot which is restricted to the municipality of Itirapina, in the state of São Paulo, Brazil. Characteristics such as the size and morphology of the leaves and bracts were important to recognize M. irregularis as a new taxon. Description, illustration, as well as comments on its morphology, distribution, conservation status, and a key for the identification of Manihot species for the state of São Paulo are presented.

Does maternal exposure to nicotine affect the oocyte quality and reproductive capacity in adult offspring?

Gonadal development begins in the intrauterine phase and females from most species are born with an established oocyte reserve. Exposure to drugs during gestation can compromise the offspring health, also affecting the gametes quality. Nicotine, the main component of cigarettes, is an oxidant agent capable of altering the fertility in men and women. As female gametes are susceptible to oxidative stress, this drug can damage the oolemma and affect oocyte maturation, induce errors during chromosomal segregation and DNA fragmentation. Oocyte mitochondria are particularly susceptible to injuries, contributing to the oocyte quality loss and embryonic development disruption. Thus, considering the high number of women who smoke during pregnancy, while significant events are occurring in the embryo for future fertility of offspring, we seek to verify the quality of the oocytes from adult rats exposed to nicotine during intrauterine phase and breastfeeding. Pregnant Wistar rats received nicotine by osmotic mini-pumps and the female progenies were evaluated in adulthood for oocyte quality (viability, lipid peroxidation, generation of reactive oxygen species and mitochondrial integrity) and reproductive capacity. Embryos (3dpc) and fetuses (20dpc) generated by these rats were also evaluated. The results showed that the dose of 2 mg/kg/day of nicotine through placenta and breast milk does not affect the number of oocytes and the fertility capacity of adult rats. However, it causes some morphological alterations in oocytes, mitochondrial changes, embryonic fragmentation and disruption of fetal development. The malformations in fetuses generated from these gametes can also indicate the occurrence of epigenetic modifications.

Uncertainty calculation methodologies in microflow measurements: Comparison of GUM, GUM-S1 and Bayesian approach.

The importance of measurement quality cannot be over emphasized in medical applications, as one is dealing with life issues and the wellbeing of society, from oncology to new-borns, and more recently to patients of the COVID-19 pandemic. In all these dire situations, the accuracy of fluid delivered according to a prescribed dose can be critical. Microflow applications are growing in importance for a wide variety of scientific fields, namely drug development and administration, Organ-on-a-Chip, or bioanalysis, but accurate and reliable measurements are a tough challenge in micro-to-femto flow operating ranges, from 2.78 × 10-4 mL/s down to 2.78 × 10-7 mL/s (1000 µL/h down to 1 µL/h). Several sources of error have been established such as the mass measurement, the fluid evaporation dependent on the gravimetric methodology implemented, the tube adsorption and the repeatability, believed to be closely related to the operating mode of the stepper motor and drive screw pitch of a syringe pump. In addition, the difficulty in dealing with microflow applications extends to the evaluation of measurement uncertainty which will qualify the quality of measurement. This is due to the conditions entailed when measuring very small values, close to zero, of a quantity such as the flow rate which is inherently positive. Alternative methods able to handle these features were developed and implemented, and their suitability will be discussed.

Morfologia do pâncreas da paca (Cuniculus paca, Linnaeus, 1766) / Morphology of the pancreas of pacas (Cuniculus paca, Linnaeus, 1766)

Este trabalho se baseou na descrição morfológica da paca (Cuniculus paca), espécie selvagem pertencente à ordem dos roedores, típica de regiões tropicais, sendo o seu conhecimento anatômico detalhado muito importante para sua conservação, experimentação e comercialização, pois ainda são escassos na literatura os trabalhos sobre morfologia de espécies selvagens. Macroscopicamente, o pâncreas da paca é formado por lóbulos, organizados em ramificações difusas, e, microscopicamente, tal órgão possui uma camada de tecido conjuntivo frouxo, a partir da qual partem septos, que dividem a glândula em lóbulos, compostos de ácinos e ilhotas pancreáticas.(AU)

The present study aimed to describe the morphology of pacas (Cuniculus paca), a wild species belonging to the order Rodentia, found in tropical areas. The detailed anatomical knowledge of pacas is very important for conservation, experimental studies and commercialization because studies in literature about wild species are scarce. The pancreas of paca has lobes organized in diffuse branches at the macroscopic level and microscopically this organ has a loose connective tissue layer, originating septa that divide the gland into lobes composed of acini and pancreatic islets.(AU)

Effect of selenium on growth and antioxidant enzyme activities of wine related yeasts.

The use of supplements in the diet is a common practice to address nutritional deficiencies. Selenium is an essential micronutrient with an antioxidant and anti-carcinogenic role in human and animal health. There is increasing interest in developing nutritional supplements such as yeast cells enriched with selenium. The possibility of producing beverages, namely wine, with selenium-enriched yeasts, led us to investigate the selenium tolerance of six wine related yeasts. The production of such cells may hamper selenium toxicity problems. Above certain concentrations selenium can be toxic inducing oxidative stress and yeast species can show different tolerance. This work aimed at studying selenium tolerance of a diversity of wine related yeasts, thus antioxidant response mechanisms with different concentrations of sodium selenite were evaluated. Viability assays demonstrated that the yeast Torulaspora delbrueckii showed the highest tolerance for the tested levels of 100 µg mL(-1) of sodium selenite. The evaluation of antioxidative enzyme activities showed the best performance for concentrations of 250 and 100 µg mL(-1), respectively for the yeast species Saccharomyces cerevisiae and Hanseniaspora guilliermondii. These results encourage future studies on the possibility to use pre-enriched yeast cells as selenium supplement in wine production.

Influence of bioaccessibility of total mercury, methyl-mercury and selenium on the risk/benefit associated to the consumption of raw and cooked blue shark (Prionace glauca).

This study aimed to identify the benefit and risk associated with raw and cooked blue shark consumption taking into account the bioaccessibility of Se, Hg and MeHg, by using in vitro digestion method. Selenium, Hg and MeHg levels were higher in cooked samples, particularly in grilled blue shark. Whereas Se bioaccessibility was above 83% in grilled samples, Hg and MeHg bioaccessibility was lower in grilled samples with values near 50%. In addition, all Se-Health Beneficial Values were negative and the molar MeHg:Se ratios were higher than one. The risk-benefit assessment yielded a maximum consumption of one yearly meal for raw or cooked blue shark, thus emphasizing the need to recommend the consumption of a wider variety of seafood species in a balanced and healthy diet.

O uso do peritônio de paca conservado em solução supersaturada de açúcar a 300 por cento ou glicerina a 98 por cento implantados na parede abdominal de ratos / The use of paca peritoneum preserved in supersaturated sugar solution 300 percent or glycerine 98 percent implanted in the abdominal wall of rats

Na busca de material biológico alternativo para a realização de implantes, objetivou-se com o presente estudo avaliar comparativamente a implantação do peritônio de paca, uma nova opção de biomaterial, conservado em solução supersaturada de açúcar a 300 por cento e conservado em glicerina a 98 por cento na parede abdominal de ratos Wistar. Foram utilizados 60 ratos, machos, da linhagem Wistar, pesando entre 150 e 200 gramas, organizados nos seguintes grupos experimentais: grupo controle (GI), grupo peritônio conservado em solução supersaturada de açúcar a 300 por cento (GII) e grupo peritônio conservado em glicerina a 98 por cento (GIII), cada um com 20 animais. Os grupos GII e GIII receberam o enxerto de peritônio da paca conservado em solução de açúcar 300 por cento e glicerina 98 por cento, respectivamente, e o grupo GI não recebeu a membrana. Cinco ratos de cada grupo foram submetidos à eutanásia em quatro momentos distintos: sete, 15, 30 e 60 dias de pós-operatório para avaliações macroscópicas e microscópicas da interface implante-tecido nativo. Apesar de reações adversas observadas em 57,5 por cento dos animais do grupo GII e GIII, em 95 por cento dos animais desses grupos houve boa cicatrização da membrana. Na análise histológica, verificou-se a presença de grande infiltrado inflamatório nos períodos iniciais (sete e 15 dias) e grande presença de tecido conjuntivo nos momentos finais (30 e 60 dias). Concluiu-se que o peritônio da paca como membrana biológica conservado nos meios estudados pode ser utilizado com segurança na parede abdominal de ratos; ainda, que sua conservação em solução supersaturada de açúcar a 300 por cento permitiu melhor maleabilidade no ato cirúrgico...

In the search for alternative biological material to perform implants, this study aimed to compare the implantation of paca peritoneum, a new biomaterial option, preserved in supersaturated sugar solution 300 percent and preserved in glycerin 98 percent in the abdominal wall of Wistar rats. A total of 60 male rats from the Wistar strain weighing between 150 and 200 grams were housed into three different experimental groups: control group (GI), peritoneum preserved in supersaturated sugar solution 300 percent group (GII) and peritoneum preserved in glycerin 98 percent group (GIII), with 20 animals each. The GII and GIII received the paca peritoneum graft preserved in sugar solution 300 percent and glycerin 98 percent, respectively and group GI did not receive any membrane. Five rats from each group were euthanized at four different times: seven, 15, 30 and 60 days post-surgery for macroscopic and microscopic evaluations in graft-native tissue interface. Despite the adverse reactions observed in 57.5 percent of GII and GIII, there was good healing of the membrane in 95 percent of the animals in these groups. Upon histological examination there was a large presence of inflammatory infiltrates in the initial periods (seven and 15 days) and a large presence of connective tissue in the final stages (30 and 60). It was concluded that the paca peritoneum as biological membrane preserved as presented in this study can be used safely in the abdominal wall of rats, the preservation in supersaturated sugar solution 300 percent allowed better flexibility during surgery...

Avaliação macroscópica e microscópica de implante de Biomembrana em estômago de coelhos (Oryctolagus cuniculus) / Macroscopic and microscopic evaluation biomembrane implant in the stomach of rabbits (Oryctolagus cuniculus)

Neste estudo foi implantado um retalho de biomembrana de látex natural em substituição a um fragmento da parede de estômago de coelhos albinos, raça Nova Zelândia, adultos, machos não castrados (n=12), com o intuito de avaliar o processo de reparação tecidual no que se refere à biocompatibilidade, à capacidade de reparação tecidual e a possíveis complicações. Aos 15, 30 e 60 dias de pós-operatório, os animais foram sacrificados, mediante o emprego de tiopental sódico (200mg kg-1), para posterior avaliação macroscópica e análise histopatológica da interface do implante com o tecido nativo. Macroscopicamente, aos 15, 30 e 60 dias de pós-operatório observou-se presença de aderências na face serosa. Aos 60 dias de pós-operatório, em todos os animais avaliados, a biomembrana não foi encontrada. Sob microscopia de luz, aos 15 e 30 dias, verificaram-se descontinuidade das camadas muscular e mucosa, presença de infiltrado inflamatório polimorfonuclear. Foram visualizados vasos sanguíneos e fibras musculares. Aos 60 dias, as camadas mucosa, muscular estavam completamente reconstituídas. O implante foi biocompatível e forneceu arcabouço para orientação e desenvolvimento das camadas teciduais do estômago, mediante processos de reparação, restabelecendo a estrutura do órgão.

In this study, biomembrane of natural latex was utilized to replace a section of the stomach wall of New Zealand rabbits, adult and non-castrated males (n=12), in order to evaluate the tissue repair process in regards to its biocompatility, scar formation ability and possible complications. The animals were euthanized at fifteen, 30 and 60 days post operation, by use of sodium thiopental (200mg kg-1), followed by macroscopic and histopathological analysis of the implant interface with the native tissue. Macroscopically, at fifteen, 30, and 60 days post operation adherence was observed in the serosal wall. At 60 days post operation, the biomembrane is not in the stomach. Under light microscopy, at fifteen and 30 days, discontinuity of muscle layer and mucosa layer, and presence of polimorfonuclear population of inflammatory cells was observed. New vessels and muscle fibers were observed. At 60 days, the mucosa and muscle layers were complete reconstituted. The implants were biocompatible and had provided the mainframe for orientation and development of the tissue layers through repairing processes, thus reestablishing the organ structure.

Growth and physiological responses to cadmium stress of two populations of Dittrichia viscosa (L.) Greuter.

Two clones of Dittrichia viscosa (L.) Greuter from contrasting populations, DV-A (metallicolous) and DV-W (non-metallicolous), were studied to compare Cd accumulation and tolerance. After 10 days of hydroponic culture with 0, 5, 10, and 15 mg Cd L(-1), metal accumulation and plant growth were measured as well as other stress markers such as decrease in the content of photosynthetic pigments, lipid peroxidation, phenols, H(2)O(2), and free proline. We also analyzed the activity of the antioxidant enzymes guaiacol and ascorbate peroxidases, catalase, superoxide dismutase, and glutathione reductase as well as their isoform patterns. Our results confirmed a high Cd tolerance and accumulation in both clones of D. viscosa, which suggests that these traits are constitutive in this species. However, when the Cd concentration in solution exceeded 10 mg Cd L(-1), DV-A was more tolerant than DV-W. The physiological mechanisms involved in Cd tolerance also differed between them, although phenols and guaiacol peroxidase played an important role in both clones. The effective Cd detoxification of DV-A consisted mainly in a promoted ascorbate peroxidase activity and better efficiency of catalase and glutathione reductase enzymes.

Estrutura, ultraestrutura e morfometria da aorta de paca (Cuniculus paca, Linnaeus, 1766) criada em cativeiro / Structure, ultrastructure and morphometry of the aorta in the paca (Cuniculus paca, Linnaeus, 1766) raised in captivity

Descreveram-se a morfologia, morfometria e ultraestrutura de segmentos das porções torácica e abdominal da aorta de quatro pacas (Cuniculus paca) adultas. Os segmentos aórticos foram analisados à microscopia de luz e à microscopia eletrônica de varredura. Mensuraram-se as espessuras do complexo formado pelas túnicas íntima e média, além da túnica adventícia. Os valores referentes à espessura do complexo formado pelas túnicas íntima e média da aorta torácica cranial foram significativamente maiores (média: 702,19µm) que os valores de outros segmentos aórticos analisados (médias: 354,18µm; 243,55µm). As camadas das paredes do vaso apresentaram variações entre si quanto à estrutura e espessura, supostamente em razão de adaptação à exigência funcional.

The aim of this study was to describe the morphology, morphometry and ultrastructure of segments of thoracic and abdominal aorta portions in four male and female paca (Cuniculus paca). Parts of the segments were examined by light microscopy and part by scanning electron microscopy. Thickness measurements of the tunica intima and media complex and tunica adventitia of the aorta were taken. In all animals the thickness values for the tunica intima and media complex of the cranial thoracic aorta were significantly higher (mean: 702.19µm) when compared to the values of other aortic segments analyzed (means: 354.18µm; 243.55µm). The layers of the vessel walls show variations in structure and thickness, presumably due to an adaptation to functionaldemand.

Morfologia do útero de cutias nulíparas e não nulíparas / Morphology of the uterus of nulliparous and non nulliparous agoutis

Descreveu-se a morfologia do útero de cutias nulíparas e não nulíparas por meio de ovariossalpingoisterectomia. A análise macroscópica do útero foi realizada in loco e na peça retirada. Segmentos das porções proximal, média e distal do órgão foram colhidas, fixadas e preparadas histologicamente, sendo as amostras analisadas à microscopia de luz, e realizada a histomorfometria das camadas uterinas. Topograficamente, o útero localiza-se na região sublombar, caudalmente aos rins, em continuação aos ovários e às tubas uterinas, estendendo-se até à entrada da pelve, onde se posiciona dorsalmente à bexiga. Caracteriza-se como do tipo duplo, embora culmine em apenas um óstio cervical externo. Microscopicamente, a mucosa uterina é formada por variações do epitélio, de cilíndrico a pseudoestratificado, que se apoia em tecido conjuntivo frouxo, onde se observam glândulas endometriais revestidas por epitélio cilíndrico, além da presença de vasos sanguíneos. A camada muscular subdivide-se em interna ou submucosa, média ou vascular e externa ou subserosa. A camada serosa é composta por tecido conjuntivo e mesotélio. Na histomorfometria, verificou-se que a espessura uterina total e a espessura da camada mucosa, em média, foram maiores nas fêmeas não nulíparas.

The uterine morphology was studied through ovarysalpingohysterectomy in nulliparous and non nulliparous agoutis (Dasyprocta azare). The uterus macroscopic analysis was done "in loco" and in the removed specimens. Fragments of the proximal, media and distal portions of this viscerae were collected, fixed and histologically prepared, and the samples analyzed through light microscopy and through the histomorphometry of the uterine layers. Topographycally, the uterus of this rodent is located on the sub lumbar area, caudally to the kidneys, and following the ovaries and uterine horns, getting through the pelvic entrance, where it is located dorsally to the bladder. It is characterized as a double uterus, although there is only an external cervical os. Microscopically, the uterine mucous is formed by epithelial elevations, from cylindrical to pseudostratified epithelium, which is supported by a loose connective tissue where endometrial glands covered by cylindrical epithelium can be observed, besides blood vessels. The muscle layer is subdivided in inner or submuscous, median or vascular and outer or subserous. The serous layer is composed of a connective tissue and mesothelium. In the histomorphometry analysis, the total uterine thickness and the mucous layer thickness, in average, were bigger on non nulliparous females.

Improvement in soil and sorghum health following the application of polyacrylate polymers to a Cd-contaminated soil.

Contamination of soils with cadmium (Cd) is a serious global issue due to its high mobility and toxicity. We investigated the application of insoluble polyacrylate polymers to improve soil and plant health. Sorghum was grown in a Cd-contaminated sandy soil. Polyacrylate polymers at 0.2% (w/w) were added to half of the soil. Control soil without plants was also included in the experiment. Growth of sorghum was stimulated in the polymer-amended soil. The concentration of Cd in the shoots, and the activities of catalase and ascorbate peroxidase decreased in plants from polymer-amended soil compared with unamended control. The amount of CaCl(2)-extractable Cd in the polymer-amended soil was 55% of that in the unamended soil. The Cd extracted in sorghum shoots was 0.19 mg per plant grown on soil without polymer and 0.41 mg per plant grown on polymer-amended soil. The total amount of Cd removed from each pot corresponded to 1.5 and more than 6% of soil CaCl(2)-extractable Cd in unamended and polymer-amended soil, respectively. The activities of soil acid phosphatase, beta-glucosidase, urease, protease and cellulase were greatest in polymer-amended soil with sorghum. In conclusion, the application of polyacrylate polymers to reduce the bioavailable Cd pool seems a promising method to enhance productivity and health of plants grown on Cd-contaminated soils.

Effects of substrate structural analogues on the enzymatic activities of aspartate aminotransferase isoenzymes.

Aspartate aminotransferase (AAT, EC 2.6.1.1) catalyses the transamination of L-asparate to oxaloacetate. It has been reported that AAT from different plant sources can catalyse the transamination of other compounds structurally similar to the natural substrates. Specificity and kinetic studies were performed with two aspartate aminotransferase isoenzymes (AAT-1 and AAT-2) from leaves of Lupinus albus L. cv Estoril using different amino donors and acceptors. Both isoenzymes showed residual activity for some of the substrates tested. Competitive inhibition was found with most of the structural analogues which is typical of a ping-pong bi-bi kinetic mechanism. It was found that both isoenzymes can use 2-amino-4-methoxy-4-oxobutanoic acid as amino donor. AAT-2 uses 2-amino-4-methoxy-4-oxobutanoic acid at a similar rate as L-aspartate but AAT-1 uses this substrate at a slower rate. The use of this amino donor by AAT isoenzymes has not been reported previously, and our results indicate structural differences between both isoenzymes.