Inter-rater reliability of the Pediatric Transplant Rating Instrument (P-TRI): challenges to reliably identifying adherence risk factors during pediatric pre-transplant evaluations

The purpose of this study was to assess the inter-rater reliability of the P-TRI, a 17-item instrument developed to identify risk factors associated with poor treatment adherence in pediatric solid organ transplant candidates. Because factors influencing treatment adherence may vary with age, the 89 subject samples were divided into pre-adolescent (0-11 yr) and adolescent (12-19 yr) groups. Each subject received two independent P-TRI ratings based on pretransplant psychosocial assessments separately conducted by a PSYC and a SWTC. Inter-rater reliability was assessed using the delta statistic. Overall, agreement was higher in the pre-adolescent group, with delta>0.70 for five items and delta<0.30 for two items. For the adolescent group, one item had a delta>0.70 and seven items had a delta<0.30. Overall, PSYC P-TRI ratings indicated fewer areas of concern on items assessing family dynamics compared with SWTC P-TRI ratings, whereas the reverse was true for items related to psychiatric history. Results highlight the challenges of conducting a reliable pretransplant assessment of adherence-related risk factors and suggest the need for revisions to the P-TRI prior to its use in clinical practice.

Enhanced dispersion in cylindrical packed beds

The effective longitudinal dispersion constant, D(L)(eff), in cylindrical packed beds is larger than in the bulk due to the existence of radial inhomogeneities induced by the cylinder walls. For dense random packed beds, D(L)(eff) can be several times larger than the bulk value, even for arbitrarily large cylinder radius, R. The time-scale for attaining asymptotic dispersion rates in a cylindrical geometry is neither the convective nor the diffusive time-scale, but rather D(T)/R(2), where D(T) is the bulk transverse dispersion rate. Similar effects are predicted for packed beds confined in ducts of any cross-sectional geometry. The case of a rectangular duct, compared with an infinite slit, provides an intuitive model for the influence of walls in the limit as R goes to infinity.

Atrazine effects on in vitro maturation and in vitro fertilization in the bovine oocyte

The effect of low levels of atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) on in vitro oocyte maturation, in vitro capacitation of sperm, or in vitro fertilization of bovine oocytes and on the quality of blastocyst formation was studied. Bovine oocytes collected from abattoir ovaries were matured, fertilized, and developed to the blastocyst stage in vitro. Embryos that reached a morula or blastocyst stage were stained with Hoechst 33258 stain to determine the number of blastomeres per embryo. Three bulls whose fertilization rates were proven consistent among straws were used for this study. Atrazine was tested at concentrations of 0.01, 0.1, 1, and 10 microM in either the maturation medium, sperm capacitation medium, or the fertilization medium. Because atrazine was dissolved in ethanol, an ethanol control was used to determine any possible effects of ethanol on the in vitro process. The addition of atrazine to both the maturation and fertilization media did not result in any significant difference in fertilization rates between the controls and the treatments. In the capacitation medium, a significant difference between the controls and the atrazine levels of 0.1, 1, and 10 microM was noted for one bull. Atrazine did not affect the number of blastomeres per embryo. There was not a significant difference (p>0.05) in the number of blastomeres per embryo between the controls and the different levels of atrazine in each medium. This study indicates that low levels of atrazine do not have an effect on in vitro fertilization rates or the number of blastomeres per embryo produced in vitro.

Children's expectations and memories of acute distress: short- and long-term efficacy of pain management interventions

OBJECTIVE

To examine the effect of psychologic and pharmacologic interventions on children's expectations and 6-month recollections of painful procedures.

METHODS

A repeated measures design allowed examination of 22 fourth graders' expectations, experiences, and memories of distress across three conditions (typical care, distraction, topical anesthetic) for a three-injection vaccination series. All participants were African American and from urban, low-income families.

RESULTS

Across conditions, children's expectations of distress were significantly higher than their experience of distress. Distress ratings did not differ among conditions prior to or immediately following the injections; however, children later recalled that the treatment conditions were superior to control for distress relief. Analyses of recall accuracy suggest that the interventions buffered the children from forming negative recollections that occurred with typical care.

CONCLUSIONS

Children have negative expectations prior to a procedure despite knowing that a distress management intervention will be employed. However, interventions may thwart the development of negative memories of distress.

The influence of husbandry schedules on the number of embryos collected from superovulated mice

We undertook this study to assess the effect of urine and fecal contamination in the cages of male mice on embryo production in females placed in these cages for breeding. Each superovulated female was placed with a stud male in a cage that was cleaned at 1, 24, or 168 h prior to breeding. Approximately 41 h after mating, embryos were flushed from the oviducts, and we determined the number of embryos and their developmental stages for each treatment group. The number of two-cell embryos collected did not differ significantly when cages were cleaned 1 or 24 h prior to mating the mice. However, significantly (p < 0.05) fewer embryos were recovered when cages were changed 168 h before the animals were mated.

Simulation of Flow in Bidisperse Sphere Packings

Simulation methods were used to construct bidisperse, random sphere packings and to calculate fluid velocities in the pore spaces under a uniform pressure gradient. Based on these calculations, the Kozeny-Carman (KC) relation was found to hold for monodisperse and bidisperse sphere packings (r(1)/r(2) = 2.6) over a range of compositions and Reynolds numbers, using the same KC parameter value (C = 5). These results are consistent with a stronger observation about the similarity of the pore-size and flow distributions. Pore-size distributions were Gaussian for all the simulated packings, and for all bidisperse mixtures and Reynolds numbers examined, the normalized longitudinal velocity distribution collapses onto an exponential distribution when scaled by the mean velocity. Copyright 1999 Academic Press.

Instructing the animal physiology graduate student in human assisted reproductive technology

Animal physiology graduate students provide an excellent personnel resource for laboratories performing human assisted reproductive technology (ART) procedures. However, the basic training of these students falls short of what is required for this highly specialized field. We designed a course to enhance their education in this area via classroom and hands-on laboratory instruction in a hospital and university setting. Topics covered in the course included in vitro maturation, in vitro fertilization, embryo culture, embryo transfer, quality control, quality assurance, micromanipulation, and cryopreservation. These techniques were applied to a group project to evaluate the influence of spermatozoal quality and quantity on early embryonic development in cattle and humans. Student grades were based on 1) oral and written examinations; 2) demonstrated competency in laboratory techniques; 3) presentation of class project data at a state academy of science meeting; and 4) initiative, determination, and interest in the coursework. Three aspects of the course stood out as very positive. First, the team approach to accomplishing a class project was new to some of the graduate students. Second, a bond was formed between hospital- and university-based faculty that did and will continue to foster unique teaching and research opportunities between the two groups. Third, the opportunity for students to present research data in a formal setting was very rewarding. This course made the students keenly aware of the many aspects of ART and provided them with specialized skills that should make them more marketable in the field of reproductive technology.