Annual protidic cycle and electrophoregrams of the savanna varan]

The circannual chronobiology of Varanus exanthematicus exanthematicus Bose, lacertilian reptile of Senegal, is characterized by a period of rest from January to June during the dry season and a period of activity from July to December during the wet season. The study of proteidemia and of the ratio of weight and height shows that the hydratation of corporal compartments is average from November to April and undergoes through changes from May to October. The electrophoresis of proteins shows the total disappearance of one of the fraction during the complete metabolic rest of the Varanus (from January to April). Finally the study of the electrophoresis of lipoproteins leads to the hypothesis that the Varanus can only make an insufficient biosynthesis of lipoproteins during the animal over feeding; besides this biosynthesis seems to be pratically stopped from January to May.     

Functional variation among frugivorous birds: implications for rainforest seed dispersal in a fragmented subtropical landscape

Seed dispersal plays a critical role in rainforest regeneration patterns, hence loss of avian seed dispersers in fragmented landscapes may disrupt forest regeneration dynamics. To predict whether or not a plant will be dispersed in fragmented forests, it is necessary to have information about frugivorous bird distribution and dietary composition. However, specific dietary information for frugivorous birds is often limited. In such cases, information on the seed-crushing behaviour, gape width and relative dietary dominance by fruit may be used to describe functional groups of bird species with respect to their potential to disperse similar seeds. We used this information to assess differences in the seed dispersal potential of frugivorous bird assemblages in a fragmented rainforest landscape of southeast Queensland, Australia. The relative abundance of frugivorous birds was surveyed in extensive, remnant and regrowth rainforest sites (16 replicates of each). Large-gaped birds with mixed diets and medium-gaped birds with fruit-dominated diets were usually less abundant in remnants and regrowth than in continuous forest. Small-gaped birds with mixed diets and birds with fruit as a minor dietary component were most abundant in regrowth. We recorded a similar number of seed-crushing birds and large-gaped birds with fruit-dominated diets across site types. Bird species that may have the greatest potential to disperse a large volume and wide variety of plants, including large-seeded plants, tended to be less abundant outside of extensive forests, although one species, the figbird Sphecotheres viridis, was much more abundant in these areas. The results suggest that the dispersal of certain plant taxa would be limited in this fragmented landscape, although the potential for the dispersal of large-seeded plants may remain, despite the loss of several large-gaped disperser species.     

A recent insertion of an alu element on the Y chromosome is a useful marker for human population studies

A member of the Alu family of repeated DNA elements has been identified on the long arm of the human Y chromosome, Yq11. This element, referred to as the Y Alu polymorphic (YAP) element, is present at a specific site on the Y chromosome in some humans and is absent in others. Phylogenetic comparisons with other Alu sequences reveal that the YAP element is a member of the polymorphic subfamily-3 (PSF-3), a previously undefined subfamily of Alu elements. The evolutionary relationships of PSF-3 to other Alu subfamilies support the hypothesis that recently inserted elements result from multiple source genes. The frequency of the YAP element is described in 340 individuals from 14 populations, and the data are combined with those from other populations. There is both significant heterogeneity among populations and a clear pattern in the frequencies of the insertion: sub-Saharan Africans have the highest frequencies, followed by northern Africans, Europeans, Oceanians, and Asians. An interesting exception is the relatively high frequency of the YAP element in Japanese. The greatest genetic distance is observed between the African and non-African populations. The YAP is especially useful for studying human population history from the perspective of male lineages.      

The effect of genistein supplementation on performance and antioxidant status of Japanese Quail under heat stress

Genistein, a phytoestrogen found in soybeans, is a powerful antioxidant. We evaluated the effects of genistein supplementation on performance, carcass characteristics, levels of malondialdehyde (MDA), homocysteine, vitamins C, E, A in Japanese quail (Coturnix coturnix japonica) exposed to high ambient temperature of 34°C. Two hundred and forty Japanese quails (10 d old) were randomly assigned to eight treatment groups consisting of 10 replicates of three birds. The birds were kept in an environmental controlled room either for 24 h/d at 22°C with (thermoneutral, TN groups) or for 16 h/d at 22°C and for 8 h/d (09.00 am to 05.00 pm) at 34°C (heat stress, HS groups). Birds were fed either a basal (control) diet (TN and HS) or the basal diet supplemented with 200, 400 or 800 mg of genistein per kg of diet. Heat exposure decreased birds' performance when basal diet was fed. Increase in feed intake and body weight, and improvement of feed efficiency and carcass traits were found in genistein-supplemented quails reared under heat stress conditions. Growth rate and feed efficiency improved in quails reared under thermo-neutral conditions as well. Concentration of serum vitamins C, E, and A increased in supplemented birds reared at high temperature, while non-significant changes occurred in TN groups. With genistein supplementation homocysteine levels in serum and MDA levels in serum and liver decreased in all birds of both TN and HS groups. Effects of genistein were relatively greater in heat-stressed quails than in quails kept under thermo-neutral conditions. Results of the present study suggest that supplementation with genistein can be considered to be protective by reducing the negative effects of oxidative stress induced by heat stress in quail.     

Lutz's spontaneous sedimentation technique and the paleoparasitological analysis of sambaqui (shell mound) sediments

Parasite findings in sambaquis (shell mounds) are scarce. Although the 121 shell mound samples were previously analysed in our laboratory, we only recently obtained the first positive results. In the sambaqui of Guapi, Rio de Janeiro, Brazil, paleoparasitological analysis was performed on sediment samples collected from various archaeological layers, including the superficial layer as a control. Eggs of Acanthocephala, Ascaridoidea and Heterakoidea were found in the archaeological layers. We applied various techniques and concluded that Lutz''s spontaneous sedimentation technique is effective for concentrating parasite eggs in sambaqui soil for microscopic analysis.     

Spermatogonial stem cell sensitivity to capsaicin: An in vitro study

Background

The placenta is an important site for iron metabolism in humans. It transfers iron from the mother to the fetus. One of the major iron transport proteins is transferrin, which is a blood plasma protein crucial for iron uptake. Its localization and expression may be one of the markers to distinguish placental dysfunction.

Methods

In the experimental study we used antibody preparation, mass spectrometric analysis, biochemical and immunocytochemical methods for characterization of transferrin expression on the human choriocarcinoma cell line JAR (JAR cells), placental lysates, and cryostat sections. Newly designed monoclonal antibody TRO-tf-01 to human transferrin was applied on human placentae from normal (n = 3) and abnormal (n = 9) pregnancies.

Results

Variations of transferrin expression were detected in villous syncytiotrophoblast, which is in direct contact with maternal blood. In placentae from normal pregnancies, the expression of transferrin in the syncytium was significantly lower (p < 0.001) when compared to placentae from abnormal ones (gestational diabetes, pregnancy induced hypertension, drug abuse).

Conclusion

These observations suggest that in the case of abnormal pregnancies, the fetus may require higher levels of transferrin in order to prevent iron depletion due to the stress from the placental dysfunction.