Radiation dose measurements with alanine/agarose gel and thin alanine films around a 192Ir brachytherapy source,using ESR spectroscopy

Alanine/agarose gel and alanine films in stacks have been used for measurements of absorbed dose around an HDR 192Ir source in a vaginal cylinder-applicator, with and without a 180 degrees tungsten shield. The gel and the films were analysed by means of ESR spectroscopy and calibrated against an ion chamber in a 4 MV photon beam to obtain absolute dose values. The gel serves as both dosimeter and phantom material, and the thin (130 microm) films are used to achieve an improved spatial resolution in the dose estimations. Experimental values were compared with Monte Carlo simulations using two different codes. Results from the measurements generally agree with the simulations to within 5%, for both the alanine/agarose gel and the alanine films.     

Attitudes about genetic risk of couples undergoing in-vitro fertilization

Many couples undergoing in-vitro fertilization (IVF) are at a higher risk of having a child with a genetic abnormality. In a sample of 55 consecutive couples starting IVF, only 33% had no genetic risk factor. The most common genetic risks were advanced maternal age and possible abnormalities associated with severe male infertility. Despite education on these risks, 71% of couples had no interest in receiving formal genetic counselling. Only 14% of couples at risk would consider using a gamete donor to avoid transmitting a genetic disorder to a child. The triple test to screen for fetal abnormalities was acceptable to 82% of couples, but only 47% planned to have amniocentesis or chorionic villi sampling. Couples were significantly more likely to opt for prenatal testing if they would consider terminating a pregnancy should the fetus have a severe genetic abnormality (P < 0.01). Roman Catholic couples tended to have more conservative attitudes about pregnancy termination. Socio-economic status and whether the infertility factor was male or female were not predictors of a couple's attitudes.      

Influence of age and cell number of a tissue culture on its susceptibility to poliovirus

Summary By means of comparative virus titrations it is shown that significantly different titers may be found as a result of experimentally produced variations in the cultures used for titrations. The results were obtained by following the cytopathic changes daily in the microscope. The applied variations concerned the following factors: Age of the cultures used, time for last fluid change before virus inoculation and cell number of cultures of same age.Supported by a grant from the Swedish Association against Polio.     

Development of dopamine innervation and turning behavior in dopamine-depleted infant rats receiving unilateral nigral transplants

Three-day-old rats were bilaterally dopamine-depleted with 6-hydroxydopamine and 3 days later cell suspensions derived from the dopamine-rich ventral mesencephalic area were injected into the right rostral striatum. The transplants rapidly developed a substantial innervation of one striatum, so that by 15 days after transplantation (21 days of age) animals rotated away from the reinnervated side in response to amphetamine. The amount of turning correlated with the extent of innervation of the striatum as determined by tyrosine hydroxylase immunocytochemistry. By 25 days post-transplantation (31 days of age), animals turned in response to stress as well as amphetamine, although this later-developing phenomenon was not associated with any significant change in the extent of dopamine innervation.

A second group of animals was bilaterally dopamine-depleted at 3 days of age, but transplantation with nigral cell suspensions was delayed until maturity. Partial reinnervation of the rostral striatum occurred with this delayed transplant paradigm, and turning to both amphetamine and stress commenced at 15 days post-transplantation. In contrast to animals receiving transplants shortly after lesioning, these animals began to turn spontaneously at about 20 days post-transplantation. The serotonin hyper-innervation that occurs following dopamine depletion in infancy was not altered by dopamine transplants made at either time.

Results from both groups of transplant animals suggest that dopamine-rich transplants can provide substantial innervation that exerts some functional control over the striatum. This occurs despite the fact that neonatally dopamine-depleted rats, unlike adult-lesioned animals, survive quite well in the absence of striatal dopamine. However, the degree of incorporation into existing circuitry, and the types of regulation that result, may vary considerably depending on the age at which the tissue is transplanted.     

Altered airway responsiveness in CD38-deficient mice

Cyclic ADP-ribose (cADPR) mobilizes calcium from intracellular stores and contributes to agonist-induced intracellular calcium elevation in airway smooth muscle (ASM). In this study we determined the functional role of CD38/cADPR signaling in the regulation of airway tone using CD38 deficient (cd38(-/-)) mice. The responsiveness to different doses of methacholine, as determined by changes in lung resistance and dynamic compliance, was significantly (P < or = 0.05) lower in cd38(-/-) mice compared with wild-type controls. To determine the mechanism responsible for the reduced responsiveness, we measured the intracellular calcium responses to contractile agonists in ASM cells. In ASM cells isolated from cd38(-/-) mice, the intracellular calcium responses to acetylcholine and endothelin-1 were significantly lower than in controls. Pretreatment of ASM cells with a cADPR antagonist resulted in attenuated intracellular calcium responses to endothelin-1 in cells isolated from wild-type mice, but not in those isolated from the cd38(-/-) mice. Very low cADPR levels and no detectable ADP-ribosyl cyclase activity were observed in lung tissue from cd38(-/-) mice, suggesting that CD38 is a critical source for cADPR synthesis. The results of the present study demonstrate that CD38/cADPR contributes to airway smooth muscle tone and responsiveness through its effects on agonist-induced elevation of intracellular calcium in ASM cells.     

Expression of human pim family genes is selectively up-regulated by cytokines promoting T helper type 1, but not T helper type 2, cell differentiation

Cytokines are the most important inducers of T helper (Th) cell differentiation. Interleukin-12 (IL-12) and interferon-alpha (IFN-alpha) are responsible for human Th1-cell differentiation, while IL-4 is the critical cytokine promoting Th2-cell development. These two subsets of cells co-ordinate immunological responses to pathogens as well as autoimmune or allergic reactions. The pim family of proto-oncogenes encodes serine/threonine-specific kinases involved in cytokine-mediated signalling pathways in haematopoietic cells. Here we demonstrate that expression of pim-1 and pim-2 mRNAs is selectively up- or down-regulated in human cord-blood-derived CD4+ cells freshly induced to polarize towards Th1 or Th2 cells, respectively, whereas their expression is inhibited in both cell types by the immunosuppressive transforming growth factor beta (TGF-beta). Moreover, the Th1-specific cytokines IL-12 and IFN-alpha, but not the Th2-specific cytokine IL-4, transiently up-regulate pim-1 and pim-2 mRNA expression in human peripheral blood T cells and natural killer cells. In addition, the Pim-1 protein levels are strongly up-regulated by Th1-specific cytokines in all of these cell types. Taken together, our results suggest that pim genes and their protein products are involved in the early differentiation process of T helper cells.     

Distribution of dengue-2 antigens by electron immunocytochemistry.

The distribution of dengue-2 antigens was studied in infected monkey kidney cells (LLC MK2) using an indirect, horseradish peroxidase-conjugated immunoglobulin technique. This procedure allowed both light and electron microscopic examination of serial-step sections of individual cells cut in a plane perpendicular to the monolayer. Both virion and nonvirion antigens were identified on the plasma membrane with this technique. A diffuse cytoplasmic reaction product was also present. The intensity and distribution of the cytoplasmic reaction product was related to disruption of the plasma membrane.