Down syndrome in British Columbia, 1952-73: incidence and mean maternal age.

Records of children with Down syndrome (DS) at the BC Health Surveillance Registry were linked to their Birth Registrations to derive maternal ages. Incidence and maternal-age specific rates were calculated for 1952-73. Mean maternal age has declined both for normal and DS children, the latter to a marked degree, so that in 1972-73 80% were born to women under 35 years. Using maternal age of 40 and over as an indication for amniocentesis would only detect 10% of DS children. The crude incidence rate (mean 1.28/1000 livebirths) has not changed appreciably over the study period except for 1969 in which a statistically significant peak occurred. The standarized rate showed an increasing trend but it is not clear whether this was a true biological increase or resulted from better ascertainment.     

Dynamic response in the larval geoduck (Panopea generosa) proteome to elevated pCO2

Pacific geoducks (Panopea generosa) are clams found along the northeast Pacific coast where they are important components of coastal and estuarine ecosystems and a major aquaculture product. The Pacific coastline, however, is also experiencing rapidly changing ocean habitat, including significant reductions in pH. To better understand the physiological impact of ocean acidification on geoduck clams, we characterized for the first time the proteomic profile of this bivalve during larval development and compared it to that of larvae exposed to low pH conditions. Geoduck larvae were reared at pH 7.5 (ambient) or pH 7.1 in a commercial shellfish hatchery from day 6 to day 19 postfertilization and sampled at six time points for an in‐depth proteomics analysis using high‐resolution data‐dependent analysis. Larvae reared at low pH were smaller than those reared at ambient pH, especially in the prodissoconch II phase of development, and displayed a delay in their competency for settlement. Proteomic profiles revealed that metabolic, cell cycle, and protein turnover pathways differed between the two pH and suggested that differing phenotypic outcomes between pH 7.5 and 7.1 are likely due to environmental disruptions to the timing of physiological events. In summary, ocean acidification results in elevated energetic demand on geoduck larvae, resulting in delayed development and disruptions to normal molecular developmental pathways, such as carbohydrate metabolism, cell growth, and protein synthesis.     

Roles of Apolipoprotein E (ApoE) and Inducible Nitric Oxide Synthase (iNOS) in Inflammation and Apoptosis in Preeclampsia Pathogenesis and Progression

Objectives

To investigate potential roles of inducible nitric oxide synthase (iNOS) and apolipoprotein (apoE) in inflammation and apoptosis promoting pathological changes in preeclampsia in pregnant mice with apoE and/or iNOS knock out.

Methods

B6.129 mice were crossed to produce WT, apoE^−/−, apoE^+/−, iNOS^−/−, iNOS^+/− and apoE^−/−iNOS^−/− groups. Variants were confirmed by PCR. Serum lipid parameters (triglycerides, TG; total cholesterol, TC; high density lipoprotein, HDL; and low density lipoprotein, LDL), NO levels and placental electronic microscopic ultrastructures were evaluated, and blood pressure (BP), 24-hour urine protein and pregnancy outcomes were recorded for pregnant F1 generation mice. Placental expressions of inflammatory (tumor necrosis factor-α, TNF-α; interleukin-6, IL-6; nuclear factor-κB, NF-κb) and apoptotic markers (Bcl-2 associated X protein, Bax, B-cell lymphoma/leukemia-2, Bcl-2, and Caspase-3) were evaluated via Western blot.

Results

Serum lipids, BP and 24-hour urine protein levels were shown to be significantly higher and parturition and placenta weights were lower in apoE^−/− and apoE^−/−iNOS^−/− groups (p<0.05). NO levels were lower in the apoE^−/−iNOS^−/− group. In addition, inflammatory/apoptosis parameters, including TNF-α, IL-6, NF-κb, Bax, Bcl-2 and Caspase-3 in the apoE^−/−iNOS^−/− group (p<0.01), as well as in the apoE^−/− group (p<0.05), and NF-κB, Bax in iNOS^−/− group (p<0.05) were higher compared with WT group. However, most of the inflammatory/apoptosis parameters in the iNOS^+/− and the apoE^+/− groups (p>0.05) showed no differences. In addition, placenta vascular endothelial and trophoblast cell morphological changes were demonstrated in both the apoE^−/−iNOS^−/− and apoE^−/− groups.

Conclusion

Elevated lipid metabolism and inflammatory/apoptosis parameters suggest a potentially significant role of apoE in preeclampsia pathology, as well as a relationship between iNOS and preeclampsia progression.     

Canonical Wnt signaling is required for ophthalmic trigeminal placode cell fate determination and maintenance

Cranial placodes are ectodermal regions that contribute extensively to the vertebrate peripheral sensory nervous system. The development of the ophthalmic trigeminal (opV) placode, which gives rise only to sensory neurons of the ophthalmic lobe of the trigeminal ganglion, is a useful model of sensory neuron development. While key differentiation processes have been characterized at the tissue and cellular levels, the signaling pathways governing opV placode development have not. Here we tested in chick whether the canonical Wnt signaling pathway regulates opV placode development. By introducing a Wnt reporter into embryonic chick head ectoderm, we show that the canonical pathway is active in Pax3+ opV placode cells as, or shortly after, they are induced to express Pax3. Blocking the canonical Wnt pathway resulted in the failure of targeted cells to adopt or maintain an opV fate, as assayed by the expression of various markers including Pax3, FGFR4, Eya2, and the neuronal differentiation markers Islet1, neurofilament, and NeuN, although, surprisingly, it led to upregulation of Neurogenin2, both in the opV placode and elsewhere in the ectoderm. Activating the canonical Wnt signaling pathway, however, was not sufficient to induce Pax3, the earliest specific marker of the opV placode. We conclude that canonical Wnt signaling is necessary for normal opV placode development, and propose that other molecular cues are required in addition to Wnt signaling to promote cells toward an opV placode fate.     

Protein kinase A phosphorylation of human phosphodiesterase 3B promotes 14-3-3 protein binding and inhibits phosphatase-catalyzed inactivation

Recent studies confirm that intracellular cAMP concentrations are nonuniform and that localized subcellular cAMP hydrolysis by cyclic nucleotide phosphodiesterases (PDEs) is important in maintaining these cAMP compartments. Human phosphodiesterase 3B (HSPDE3B), a member of the PDE3 family of PDEs, represents the dominant particulate cAMP-PDE activity in many cell types, including adipocytes and cells of hematopoietic lineage. Although several previous reports have shown that phosphorylation of HSPDE3B by either protein kinase A (PKA) or protein kinase B (PKB) activates this enzyme, the mechanisms that allow cells to distinguish these two activated forms of HSPDE3B are unknown. Here we report that PKA phosphorylates HSPDE3B at several distinct sites (Ser-73, Ser-296, and Ser-318), and we show that phosphorylation of HSPDE3B at Ser-318 activates this PDE and stimulates its interaction with 14-3-3 proteins. In contrast, although PKB-catalyzed phosphorylation of HSPDE3B activates this enzyme, it does not promote 14-3-3 protein binding. Interestingly, we report that the PKA-phosphorylated, 14-3-3 protein-bound, form of HSPDE3B is protected from phosphatase-dependent dephosphorylation and inactivation. In contrast, PKA-phosphorylated HSPDE3B that is not bound to 14-3-3 proteins is readily dephosphorylated and inactivated. Our data are presented in the context that a selective interaction between PKA-activated HSPDE3B and 14-3-3 proteins represents a mechanism by which cells can protect this enzyme from deactivation. Moreover, we propose that this mechanism may allow cells to distinguish between PKA- and PKB-activated HSPDE3B.