Lipid Composition of Whole Roots and of Ca2+, Mg2+-activated Adenosine Triphosphatases from Wheat and Oat as Related to Mineral Nutrition

Lipid composition of whole roots of wheat (Triticum vulgare Vill. cv. Svenno Spring Wheat) and oat (Avena sativa L. cv. Brighton) and of cell wall fractions, mitochondrial fractions and microsomal fractions of these roots were studied. Lipid composition depended upon the level of mineral nutrition. In wheat total phospholipids, phosphatidyl choline and sulfolipid content was highest in the roots grown at the higher salt concentration, while the reverse was true for oat roots. In both species glycolipid and sterol content was lower in the high salt roots, at the same time as higher proportions of them were built into the microsomal fraction. Phosphatidyl choline content of the wheat root membrane fractions increased with the salt level, while the opposite occurred in the oat roots. The phosphatidyl choline content may be correlated with the (Ca²⁺, Mg²⁺)-stimulated ATPase activity.     

Mitotic activity and nuclear/cytoplasmatic ratio of the lachrymal and Harderian glands of the rat during postnatal life.

The authors performed a study of the mitotic activity and the nuclear/cytoplasmic (N/C) ratio during postnatal life of the lachrymal and Harderian glands of the rat. Based on the results, they concluded: (1) during the first days of postnatal life the development of lachrymal and Harderian glands was characterized by an intense mitotic activity and a low N/C ratio; (2) the period prior to eyelid disjunction was characterized by a diminished mitotic activity and a progressive and slow increase of the N/C ratio; (3) after eyelid disjunction, mitotic activity was reduced and an abrupt increase of the N/C ratio occurred, more evident in the Harderian gland; (4) during the final period of postnatal life studied mitotic activity was absent and the N/C ratio presented a higher, more constant level, which was always higher for the Harderian gland.     

Allometric study of the lachrymal and Harderian glands of the rat during postnatal life.

The authors performed an allometric study of the growth of the rat's lachrymal and Harderian glands, during postnatal life. From the analysis of the results, they could conclude: (1) the growth of these glands in relation to body weight, during postnatal life, could be considered similar, following the allometric law; (2) the differential growth of the glands occurred in two stages: from birth until the 15th day and from the 15th day until the final period of life studied; (3) the two stages of development were separated by a critical period, during which an abrupt modification of the allometric coefficient occurred; (4) during the first days of postnatal life, the development of the Harderian gland was characterized by a high rate of growth and, just after eyelid disjunction and during rest of postnatal life, by a rate of allometric of growth less than 1. It is interesting to observe that the lachrymal and Harderian glands' critical period of development on the 15th day of postnatal life coincides with the time at which the eyelids of the animal open.     

DHEA effects on myocardial Akt signaling modulation and oxidative stress changes in aged rats

The secretion of DHEA-synthesized mainly in the adrenal cortex-increases in the postnatal aging, peaks in the twenties and decreases with age afterwards. Exogenous DHEA can exert a dual effect depending on dose and on tissue. Akt is a serine/threonine kinase whose activity has been seen as an interventional approach for cardiomyopathic damage resulting from aging changes. In order to evaluate DHEA effects over myocardial Akt protein expression associated to oxidative stress markers during aging, male Wistar rats (3 and 18 months) were assigned into two groups: control or DHEA (10 mg/kg, subcutaneously, for 5 weeks). In the aged group, we found increased lipid peroxidation and glutathione-S-transferase activity. DHEA produced an increase in p-Akt protein expression and a decrease in SOD activity in both ages. Akt pathway activation might be related to changes in oxidative stress parameters according to age.     

Complementary retrieval of 16S rRNA gene sequences using broad-range primers with inosine at the 3'-terminus: implications for the study of microbial diversity

We evaluated the impact of the base analogue inosine substituted at the 3'-terminus of broad-range 16S rRNA gene primers on the recovery of microbial diversity using terminal restriction fragment length polymorphism and clonal analysis. Oral plaque biofilms from 10 individuals were tested with modified and unmodified primer pairs. Besides a core overlap of shared terminal restriction fragments (T-RFs), each primer system provided unique information on the occurrence of T-RFs, with a higher number generally displayed with inosine primers. All clones sequenced were at least 99% identical to publicly available full-length sequences. Analysis of the corresponding primer-binding sites showed that most sequence types were 100% complementary to the unmodified primers so that the characteristic of inosine to bind with all four nucleotides was not crucial for the observed increase in microbial richness. Instead, differences in community compositions were correlated with the identity of the nearest-neighbor 3' of the primer-targeting region. By influencing the thermal stability of primer hybridization, this position may play a previously unrecognized role in biased amplification of 16S rRNA gene sequences. In conclusion, the combined use of inosine and unmodified primers enables the complementary retrieval of 16S rRNA gene types, thereby expanding the observed diversity of complex microbial communities.     

Drosophila melanogaster lipins are tissue-regulated and developmentally regulated and present specific subcellular distributions

Lipins constitute a novel family of Mg(2+)-dependent phosphatidate phosphatases that catalyze the dephosphorylation of phosphatidic acid to yield diacylglycerol, an important intermediate in lipid metabolism and cell signaling. Whereas a single lipin is detected in less complex organisms, in mammals there are distinct lipin isoforms and paralogs that are differentially expressed among tissues. Compatible with organism tissue complexity, we show that the single Drosophila Lpin1 ortholog (CG8709, here named DmLpin) expresses at least three isoforms (DmLpinA, DmLpinK and DmLpinJ) in a temporal and spatially regulated manner. The highest levels of lipin in the fat body, where DmLpinA and DmLpinK are expressed, correlate with the highest levels of triacylglycerol (TAG) measured in this tissue. DmLpinK is the most abundant isoform in the central nervous system, where TAG levels are significantly lower than in the fat body. In the testis, where TAG levels are even lower, DmLpinJ is the predominant isoform. Together, these data suggest that DmLpinA might be the isoform that is mainly involved in TAG production, and that DmLpinK and DmLpinJ could perform other cellular functions. In addition, we demonstrate by immunofluorescence that lipins are most strongly labeled in the perinuclear region of the fat body and ventral ganglion cells. In visceral muscles of the larval midgut and adult testis, lipins present a sarcomeric distribution. In the ovary chamber, the lipin signal is concentrated in the internal rim of the ring canal. These specific subcellular localizations of the Drosophila lipins provide the basis for future investigations on putative novel cellular functions of this protein family.     

Biologic, morphologic, and molecular characterisation of Neospora caninum isolates from littermate dogs

Isolation and biologic and molecular attributes of Neospora caninum from three littermate dogs are described. Tissue cysts were confined to the brain and striated muscles. N. caninum was isolated (isolates NC-6, NC-7, and NC-8) in rodents and cell culture that had been inoculated with brain tissue from the dogs. Schizont-like stages reactive with N. caninum antibodies were seen in cell cultures seeded with bradyzoites released from Percoll-isolated N. caninum tissue cysts from the brain of one dog. Tissue cysts were infective orally to mice and gerbils, but not to cats and dogs. The isolates were also identified as N. caninum by PCR and sequence analysis.     

Isolation and genotyping of Toxoplasma gondii from free-ranging chickens from Argentina

The prevalence of Toxoplasma gondii in free-ranging chickens can be considered a good indicator of the prevalence of T. gondii oocysts in the environment because chickens feed from the ground. In the present study, prevalence of T. gondii in 29 free-range chickens (Gallus domesticus) from Argentina was investigated. Blood, heart, and brain from each chicken were examined for T. gondii infection. Antibodies to T. gondii, assayed with the modified agglutination test (MAT), were found in 19 of 29 (65.5%) chickens. Hearts and brains of seropositive (MAT > or = 1:5) chickens were bioassayed in mice. Toxoplasma gondii was isolated from 9 of 19 seropositive chickens. Genotyping of chicken isolates of T. gondii using the SAG2 locus indicated that 1 was type I, 1 was type II, and 7 were type III. This is the first report of isolation of T. gondii from chickens from Argentina.