Reduced uterine and ovarian size in adolescent girls born small for gestational age

Reduced fetal growth is known to be associated with a reduced ovarian fraction of primordial follicles, with ovarian hyperandrogenism and anovulation in late adolescence. In this study, we examined whether adolescent girls born small for gestational age also present an abnormality in uterine or ovarian size. Standardized ultrasound measurements of the internal genitalia were performed in 36 healthy post-menarcheal girls (mean age 14 y) born with a size that was either appropriate for gestational age (AGA) or small (SGA), birth weight averaging 0.1 and -3.0 SD, respectively; clinical and endocrine characteristics were documented concomitantly. Compared with AGA girls, the SGA girls had a smaller uterus (mean difference of 20%; p < 0.006) and a reduced ovarian volume (mean difference of 38%; p < 0.0002). In conclusion, the gynecological correlates of prenatal growth restriction are herewith extended to include a reduced size of the uterus and the ovaries.     

Hand exercise effect in maturation and blood flow of dialysis arteriovenous fistulas ultrasound study

With the help of the Doppler Ultrasound we have measured the radial artery blood flow of 20 healthy volunteers and the fistula flow of 40 uraemic patients. The measurements were made at rest and repeated one, three and five minutes after initiation of hand exercise, and one minute after the exercise had finished. Radial artery mean flow increased significantly with the exercise (p less than 0.001); radial arteries with greater baseline flow had less flow increase (p less than 0.002). However, we were not able to demonstrate any fistula flow increase with the hand exercise. Therefore, we conclude that there is no benefit in advising uraemic patients to squeeze a rubber ball which, otherwise, supposes an unnecessary preoccupation for these patients.     

Ultrastructural localization of diaminobenzidine reactivity in leishmania donovani promastigotes.

The ultrastructural localization of the activities of two enzyme systems in the culture forms of Leishmania donovani was shown by means of the diaminobenzidine techniques. The consistent deposition of electron dense reaction product of DAB oxidation without H2O2 in the kinetoplast and mitochondrial cristae and membranes was taken as evidence of the presence of cytochrome oxidase activity and cytochrome c. In the presence of H2O2, a more intense DAB oxidation was attributed to the activity of a peroxidase, possibly cytochrome c peroxidase. Mitochondrial and kinetoplast reactions to DAB were completely inhibited by KCN, methanol-nitroprusside, and by heating to 50 degrees C for 10 min. On the other hand, no inhibitory effect was observed with 100 mM 3-amino-1,2,4-triazole. Under all conditions of incubation tested, the microbodies were completely unreactive to DAB staining, which was utilized as the basis for their identification. These organelles are rounded, moderately electron-opaque bodies with a finely granular matrix and fine tubules or cores and are limited by a single membrane. Under normal staining method, the microbodies were indistinguishable from the rounded sections of mitochondria.     

Habitats, dispersion and invasion of sylvatic Triatoma dimidiata (Hemiptera: Reduviidae: Triatominae) in Petén, Guatemala

Dispersion and invasion capacity of sylvatic populations of Triatoma dimidiata (Latreille) were investigated during 14 mo by means of experimental chicken coops installed in a nature reserve within the Maya Biosphere, Petén, Guatemala. In addition, palm trees, underground archeological holes (chultunes) and piles of limestones within the forest were inspected as potential sylvatic habitats of T. dimidiata. From the three types of sylvatic habitats we inspected, all served as shelter and breeding sites for T dimidiata. The natural infection of these bugs (n = 72) with Trypanosoma cruzi (Chagas) was high (25%) and represent a risk for humans who colonize the forest. T. dimidiata quickly invaded the experimental chicken coops installed in the primary forest, albeit at very low densities. However, only one adult bug was encountered in the chicken coops installed in a secondary forest. Dispersal of adult T. dimidiata was most apparent at the end of the dry season. Overall, our results indicate a potential risk for invasion by sylvatic T. dimidiata of domestic environments in this area, with a risk of T. cruzi transmission to humans. We suggest that a system of community-based surveillance should be developed to detect new infestations and organize prompt treatment of any new cases of acute Chagas disease that may result.     

Hypothalamic Y2 receptors regulate bone formation

Neuropeptide Y (NPY) is a downstream modulator of leptin action, possibly at the level of the arcuate nucleus where NPY neurons are known to express both leptin receptors and Y2 receptors. In addition to the well-described role of NPY and leptin in energy balance and obesity, intracerebroventricular administration of NPY or leptin also causes bone loss. Here we show that Y2 receptor-deficient mice have a twofold increase in trabecular bone volume as well as greater trabecular number and thickness compared with control mice. We also demonstrate that central Y2 receptors are crucial for this process, since selective deletion of hypothalamic Y2 receptors in mature conditional Y2 knockout mice results in an identical increase in trabecular bone volume within 5 weeks. This hypothalamus-specific Y2 receptor deletion stimulates osteoblast activity and increases the rate of bone mineralization and formation, with no effect on osteoblast or osteoclast surface measurements. The lack of any changes in plasma total calcium, leptinemia, or hypothalamo-pituitary-corticotropic, -thyrotropic, -somatotropic, or -gonadotropic output suggests that Y2 receptors do not modulate bone formation by humoral mechanisms, and that alteration of autonomic function through hypothalamic Y2 receptors may play a key role in a major central regulatory circuit of bone formation.