Vitamin D receptor distribution in intestines of domesticated sheep Ovis ammon f. aries

The biologically active form of vitamin D, i.e., 1,25-dihydroxycholecalciferol or calcitriol, plays an important role in bone metabolism and calcium homeostasis, which is often disturbed at the onset of lactation in high milk-yielding domestic ruminants. Gene transcription is modulated via vitamin D receptors, but nongenomic effects of vitamin D via membrane receptors have also been described. In the intestines, vitamin D promotes calcium absorption via vitamin D receptors. Vitamin D receptors are of clinical relevance, but have not been systematically assessed within all segments of the intestine in any species. Thus, we present for the first time an immunohistochemical study of the distribution patterns of the vitamin D receptor protein in sheep, which may be the basis for present and future investigations on mineral homeostasis in domestic ruminants. Tissue probes of the intestines were collected from five lambs and five nonlactating and nonpregnant dams, fixed in formalin, embedded in paraffin, and used for the assessment of vitamin D receptor protein. Nuclear vitamin D receptor immunoreaction was scored semiquantitatively and exhibited a segment-specific distribution pattern. Goblet cells always were devoid of any vitamin D receptor immunoreaction. Surface epithelial cells and enterocytes of the crypt openings generally demonstrated only a weak immunoreaction. Basally and/or intermediately located crypt epithelial cells exhibited stronger immunoreactions in duodenum, jejunum, and colon descendens. This basal/intermediate to superficial gradient was most pronounced in the duodenum and less evident in jejunum and colon descendens and not observed in ileum and cecum. There were no age-dependent variations in vitamin D receptor protein expression. Results demonstrate that intestinal vitamin D receptor distribution patterns are segment-specific and strongest immunoreactions correlate with highest intestinal calcium absorptive activities, as reported in literature. Strong expression of vitamin D receptors within the lower half of crypts also suggests a role for calcitriol in epithelial differentiation and cellular homeostasis

Seroprevalence of Trypanosoma cruzi in Rural Ecuador and Clustering of Seropositivity within Households

We performed a cross-sectional study of Trypanosoma cruzi seroprevalence in 14 communities in three provinces of Ecuador and estimated the magnitude of the association of seropositive individuals within households. A total of 3,286 subjects from 997 households were included. Seroprevalence was 5.7%, 1.0%, and 3.6% in subjects in the Manabí, Guayas, and Loja provinces, respectively. Seroprevalence increased with increasing age in Manabí and Guayas, whereas in Loja, the highest prevalence occurred in children ≤ 10 years of age. In the coastal provinces, clustering of seropositives within households was not observed after adjustment for other household factors. However, in the Andean province of Loja, the odds of seropositivity were more than two times greater for an individual living in a household with another seropositive person. Our results indicate that transmission of T. cruzi is ongoing in Ecuador, although intensity of transmission and mechanisms of interaction between humans and the insect vectors of disease vary between geographic regions

Immunohistochemical demonstration of vitamin D receptor distribution in goat intestines

Vitamin D (VD) plays an important role in calcium homeostasis. 1,25-Dihydroxycholecalciferol or calcitriol modulates gene transcription via nuclear VD receptors (VDR). In the intestines, VD promotes calcium resorption via VDR. VDR has not been systematically assessed within the intestine in any species. We therefore present a semiquantitative immunohistochemical study of the distribution patterns of VDR in goat intestines. Intestinal tissue probes were collected from 5 lambs and 5 non-lactating non-pregnant dams, fixed in formalin, embedded in paraffin and assessed for VDR. Nuclear VDR immunoreaction was scored semiquantitatively. VDR exhibited a segment-specific distribution pattern. Goblet cells were always devoid of VDR. Enterocytes within the surface epithelium and the superficial crypts generally demonstrated only a weak immunoreaction along the length of the intestine, while basally and/or intermediately located crypt epithelial cells exhibited strong VDR immunoreactions in the duodenum, jejunum and colon descendens. The difference in VDR staining between deep and superficial locations was most prominent in the duodenum and less evident in the jejunum, ileum and colon descendens. Results demonstrate that VDR distribution exhibits cell type-, segment- and location-specific patterns in the goat. Data may serve as a basis for future experiments on the role of VDR in Ca metabolism

The effects of a child's self-evaluation program on compliance with parental instructions in the home.

A self-evaluation program was implemented with a kindergarten-aged boy in the home to increase compliance with parent instructions and decrease inappropriate verbal behavior. The self-evaluation package included the child's assessing the appropriateness of his behavior in 5-min intervals, receiving chips for positive self-evaluations, and exchanging chips for a reward following experimental sessions. In a reversal design, analyses were conducted of the effectiveness of the self-evaluation program, the requisite conditions for effective child behavior change with a self-evaluation approach, and the parent's efficiency in using the self-evaluation package. The self-evaluation procedures typically resulted in increased compliant behavior and decreased inappropriate behavior, although the effects generally weakened with time. Behavioral gains were greater and better maintained when the self-evaluation procedures were preceded by a phase of external evaluation via the mother than by baseline, suggesting that self-evaluation procedures may serve more to maintain the effects of external evaluation rather than to induce their own changes. The parent generally was efficient in implementing the procedures. Research and clinical implications for using self-evaluation procedures in a home setting are discussed