Relative DNA content in diploid, polyploid, and multiploid species of Paspalum (Poaceae) with relation to reproductive mode and taxonomy.

It is generally accepted that polyploids have downsized basic genomes rather than additive values with respect to their related diploids. Changes in genome size have been reported in correlation with several biological characteristics. About 75 % of around 350 species recognized for Paspalum (Poaceae) are polyploid and most polyploids are apomictic. Multiploid species are common with most of them bearing sexual diploid and apomictic tetraploid or other ploidy levels. DNA content in the embryo and the endosperm was measured by flow cytometry in a seed-by-seed analysis of 47 species including 77 different entities. The relative DNA content of the embryo informed the genome size of the accession while the embryo:endosperm ratio of DNA content revealed its reproductive mode. The genome sizes (2C-value) varied from 0.5 to 6.5 pg and for 29 species were measured for the first time. Flow cytometry provided new information on the reproductive mode for 12 species and one botanical variety and supplied new data for 10 species concerning cytotypes reported for the first time. There was no significant difference between the mean basic genome sizes (1Cx-values) of 32 sexual and 45 apomictic entities. Seventeen entities were diploid and 60 were polyploids with different degrees. There were no clear patterns of changes in 1Cx-values due to polyploidy or reproductive systems, and the existing variations are in concordance with subgeneric taxonomical grouping.

Alkaline ribonuclease activity in maternal serum and in serum of newborns from birth up to thirty days of age. A study made with full-term appropriate-, full-term small- and preterm appropriate-for-gestational-age infants.

We have studied the alkaline ribonuclease (RNase) activity in maternal serum and serum of full-term small- (T-SGA), full-term appropriate- (T-AGA) and preterm appropriate-for-gestational age (PT-AGA) newborns. A significantly lower level of RNase was observed in T-AGA and T-SGA newborns on the 30th day of age and in PT-AGA newborns on the 15th and 30th days of age, as compared to other T-AGA, T-SGA and PT-AGA groups of infants at birth. RNase activity was significantly higher in cord blood than in the maternal blood in all categories studied. Moreover, in preterm newborns, RNase activity in cord blood was significantly higher in those presenting a lower gestational age. We did not observe any significant difference in RNase levels in the cord blood of newborns from the 3 categories studied. The same results were observed concerning maternal blood. We, therefore, conclude that RNase activity in cord blood or in maternal blood is not a very satisfactory indicator of fetal malnutrition.

Effects of intrauterine malnutrition on brain free amino acids of young rats, after nutritional recovery during lactation period.

The effect of protein-calorie malnutrition during gestation on the brain amino acids of rat pups was studied following nutritional recovery during lactation. The brain amino acids of rat pups born to dam rats malnourished during gestation were studied after these rat pups received proper nutrition during lactation. Pregnant rats were fed a 1% protein diet with total caloric intake restricted to half that of controls. After birth, the offspring of rats fed on deficient diets were nurtured up to the 28th day postpartum by foster mothers receiving adequate diets. At this time, the offspring were killed. The control group consisted of offspring from pregnant rats fed a diet with adequate protein (21%) and calories during the entire gestation and lactation period. Quantitation of brain amino acids in the pups at 28 days postpartum showed lower concentrations of essential and nonessential amino acids in the rats malnourished during gestation. Concentrations of histidine, glycine, and alpha-aminobutyric acid were all reduced. These findings demonstrate that the brains of rat pups malnourished during gestation show persistent decreases in specific brain amino acids after adequate postpartum nutrition.

[Intrauterine malnutrition in rats. II. Study of weight and mortality of the offspring]. / Desnutrição intrauterina em ratos. II Estudo do peso e mortalidade do produto da concepção.

Rats were submitted to protein-calorie deprivation during different periods of gestation and the body weight and mortality of offspring were evaluated at 0, 28 and 90 days of age. The body weight was considered adequate (n) when the values were up to 2 SD below the mean values of control animals, or inadequate (d) when the values were below 2 SD. Rats of the control group (C) were fed ad libitum (protein 21%), and the rats of the experimental groups were fed during all gestational period (D), during the first half (D1) or second half of pregnancy (D2), with a diet containing 1% of protein, and the intake reduced to 50%. Significant differences were observed in the ponderal evolution for all experimental groups. Group D was the most damaged, with the greatest ponderal deficiency and the greatest mortality rates. Similar behavior was observed for D2. Group D1 was similar to C with the best results and the lowest mortality rate.

Desnutricao intrauterina em ratos.II. Estudo do peso e mortalidade do produto da concepcao. / Intrauterine malnutrition in rats. II. Study of the weight and mortality of the offspring

Ratas foram submetidas a desnutricao proteico-calorica durante varios periodos da gestacao e o peso corporal e mortalidade da ninhada foram estabelecidos aos 0,28 e 90 dias de vida. O peso corporal foi considerado adequado (n), quando se situava ate dois desvios-padrao abaixo da media de animais controles, ou inadequado (d) quando se situava abaixo de dois desviospadrao. As ratas do grupo controle (C) foram alimentadas ad libitum (proteina 21%) e os grupos experimentais foram alimentados durante toda a gestacao (D), na primeira metade (Dl) ou segunda metade (D2) com dieta contendo l% de proteina, sendo a quantidade oferecida reduzida a 50%. Foram observadas diferencas significativas na evolucao ponderal para todos os grupos experimentais. O grupo D foi o mais seriamente comprometido, com os maiores deficits ponderais e maiores indices de mortalidade; comportamento semelhante foi observado para o grupo D2. O grupo Dl apresentou comportamento proximo ao C, com os melhores resultados e menores indices de mortalidade

[Behavior of calcium, phosphorus and magnesium in rats subjected to malnutrition in different stages of the gestational period]. / Comportamento do cálcio, fósforo e magnésio em ratas submetidas á desnutrição durante varias etapas no período gestacional.

An attempt was made to point out the alterations in serum calcium, phosphorus and magnesium, during gestation in female rats fed ad libitum normal diets (protein content, 21%), a protein-calorie deficient diet (protein content, 1%) in a quantity equal to half of that given to normal rats. As the data revealed, in the control group of pregnant rats a significant increase in calcium on the 17th and 19th days was observed, as well as a decrease at the end of gestation. The values remained at higher levels in this group than those detected in the control non-pregnant rats. The above-mentioned increase was not observed in the undernourished pregnant rats, which showed an evident decrease. The behavior of phosphorus in the control pregnant rats was similar to calcium behavior, but this "ion" had not suffered the influence of malnutrition when isolatedly imposed. With regard to magnesium, we noticed that throughout the experiment serum concentration was not influenced either by malnutrition or by gestation. Malnutrition itself was the greatest responsible factor as judged by the differences observed among the groups.