Ultrasonographic assessment of the endometrium in rhesus monkeys during the normal menstrual cycle

This study was undertaken to determine whether cyclical changes in the endometrium of the rhesus monkey could be observed by using ultrasound. Three indices of endometrial size were examined: the antero-posterior (or ventro-dorsal), longitudinal, and transverse diameters. Changes in the ultrasonic reflectivity of the endometrium were also assessed. We have attempted to correlate these endometrial parameters with the hormonal status of the animal. Ultrasonography was performed for an average of 12 consecutive days during 19 menstrual cycles. All ultrasonic recordings were normalized to the day of the estradiol (E2) peak (Day 0). We found that the reflectivity of the endometrium was dependent on the stage of the cycle: during the follicular phase, the endometrium appeared less echogenic (darker) compared to the myometrium; in the luteal phase, the endometrium was more echogenic (lighter). During the follicular phase (Days -9 to 0), there was a linear increase in the antero-posterior (p less than 0.001), longitudinal (p less than 0.05), and transverse (p less than 0.001) diameters. In the luteal phase (Days 1-15), no significant changes were observed in these diameters. An estimated endometrial volume (EEV) was obtained by the product of the antero-posterior, longitudinal, and transverse diameters. Each animal observed during the follicular phase (n = 14) exhibited a peak in the EEV, which correlated with the day of the E2 peak (p less than 0.01). From this study, we conclude that the sonographic appearance of the endometrium of the rhesus monkey reflects the cyclical changes that occur during the menstrual cycle.(ABSTRACT TRUNCATED AT 250 WORDS)     

Pulmonary vasodilatory response to neurohypophyseal peptides in the rat.

Experiments were performed on isolated salt-perfused rat lungs to determine the receptor type(s) responsible for the pulmonary vascular effects of the neurohypophyseal peptides arginine vasopressin (AVP) and oxytocin. Bolus administration of AVP to lungs preconstricted with the thromboxane mimetic U-46619 resulted in a dose-dependent vasodilatory response (approximately 65% reversal of U-46619-induced vasoconstriction at the highest dose tested) that was blocked by pretreatment with a selective V1- but not by a selective V2-vasopressinergic receptor antagonist. Administration of a selective V1-agonist to the preconstricted pulmonary vasculature resulted in a vasodilatory response similar to that observed with AVP (approximately 55% reversal of U-46619 vasoconstriction), which was blocked by prior administration of the selective V1-receptor antagonist. Administration of the selective V2-receptor agonist desmopressin to the preconstricted pulmonary vasculature resulted in a small (approximately 8% reversal of U-46619 vasoconstriction) vasodilatory response that was, nevertheless, greater than that produced by addition of vehicle alone and was attenuated by pretreatment with a selective V2-receptor antagonist. Finally, oxytocin also caused vasodilation in the preconstricted pulmonary vasculature; however, the potency of oxytocin was approximately 1% of AVP, and the vasodilation produced by oxytocin was blocked by prior administration of a selective V1-receptor antagonist, suggesting that oxytocin acts via V1-vasopressinergic receptor stimulation. We conclude from these experiments that AVP and oxytocin dilate the preconstricted pulmonary vasculature primarily via stimulation of V1-vasopressinergic receptors. V2-receptor stimulation results in a minor vasodilatory response, although its physiological significance is unclear.     

Developmental delays in exploration and locomotor activity in male rats exposed to low level lead

Delays in the development of exploratory and locomotor behavior in neonatal male rats (up to 21 days of age) are shown to accrue as a consequence of low level lead exposure. Cross fostering experiments indicate that these delays are primarily due to prenatal exposure. These Pb induced behavioral modifications appear to be associated with the delays in synaptogenesis and biochemical development of the cerebral cortex reported previously (4, 18). A new behavioral bioassay for detecting delays in brain development is described.     

Seed germination,seedling inoculation and establishment ofAlnus spp. in containers in greenhouse trials

Methods for production of containerized seedlings ofAlnus species were developed which permit nitrogen-fixing nodules to form on the root systems prior to outplanting, in order to provide an early nitrogen input during seedling establishment. The methods are based on procedures for inoculating root systems with suspensions ofFrankia (Actinomycetales), applied either directly in the container cell as a soil drench at the time of seeding, or as a root dip for seedlings transplanted into the containers. Germination of dried, stored seed was enhanced by light and by presoaking for 16 h in water. Pretreatments to overcome seed dormancy or to eliminate fungal pathogens did not further enhance germination. Some loss of seedlings was recorded in the early stages of growth shortly after germination, which is a factor in calculating projected seedling yield. Nodulation and seedling growth were evaluated in terms of growth media characteristics. Seedlings performed well in peat-vermiculite, at soil pH between 5.5 and 8.0.     

Natural relationship between bacteroides and flavobacteria.

Comparisons among 16S rRNA sequences from various eubacteria reveal a natural relationship between the bacteroides (represented by the Bacteroides fragilis sequence) and a phylogenetic unit that comprises the flavobacteria, cytophagae, flexibacteria, and others (represented by the Flavobacterium heparinum sequence). Although the relationship is not a close one, it is, nevertheless, specific. rRNAs from these two organisms are not only closer to one another in overall sequence than they are to outgroup species (such as Bacillus subtilis, Escherichia coli, Desulfovibrio desulfuricans, and Agrobacterium tumefaciens), but they show common idiosyncrasies (i.e., derived characteristics) in both rRNA sequences and higher-order structures.