A programmable dual-targeting siRNA scaffold supports potent two-gene modulation in the central nervous system.

Divalent short-interfering RNA (siRNA) holds promise as a therapeutic approach allowing for the sequence-specific modulation of a target gene within the central nervous system (CNS). However, an siRNA modality capable of simultaneously modulating gene pairs would be invaluable for treating complex neurodegenerative disorders, where more than one pathway contributes to pathogenesis. Currently, the parameters and scaffold considerations for multi-targeting nucleic acid modalities in the CNS are undefined. Here, we propose a framework for designing unimolecular 'dual-targeting' divalent siRNAs capable of co-silencing two genes in the CNS. We systematically adjusted the original CNS-active divalent siRNA and identified that connecting two sense strands 3' and 5' through an intra-strand linker enabled a functional dual-targeting scaffold, greatly simplifying the synthetic process. Our findings demonstrate that the dual-targeting siRNA supports at least two months of maximal distribution and target silencing in the mouse CNS. The dual-targeting divalent siRNA is highly programmable, enabling simultaneous modulation of two different disease-relevant gene pairs (e.g. Huntington's disease: MSH3 and HTT; Alzheimer's disease: APOE and JAK1) with similar potency to a mixture of single-targeting divalent siRNAs against each gene. This work enhances the potential for CNS modulation of disease-related gene pairs using a unimolecular siRNA.

A programmable dual-targeting di-valent siRNA scaffold supports potent multi-gene modulation in the central nervous system.

Di-valent short interfering RNA (siRNA) is a promising therapeutic modality that enables sequence-specific modulation of a single target gene in the central nervous system (CNS). To treat complex neurodegenerative disorders, where pathogenesis is driven by multiple genes or pathways, di-valent siRNA must be able to silence multiple target genes simultaneously. Here we present a framework for designing unimolecular "dual-targeting" di-valent siRNAs capable of co-silencing two genes in the CNS. We reconfigured di-valent siRNA - in which two identical, linked siRNAs are made concurrently - to create linear di-valent siRNA - where two siRNAs are made sequentially attached by a covalent linker. This linear configuration, synthesized using commercially available reagents, enables incorporation of two different siRNAs to silence two different targets. We demonstrate that this dual-targeting di-valent siRNA is fully functional in the CNS of mice, supporting at least two months of maximal target silencing. Dual-targeting di-valent siRNA is highly programmable, enabling simultaneous modulation of two different disease-relevant gene pairs (e.g., Huntington's disease: MSH3 and HTT; Alzheimer's disease: APOE and JAK1) with similar potency to a mixture of single-targeting di-valent siRNAs against each gene. This work potentiates CNS modulation of virtually any pair of disease-related targets using a simple unimolecular siRNA.

Formation of Reversible Clusters with Controlled Degree of Aggregation.

We develop a reversible colloidal system of silica nanoparticles whose state of aggregation is controlled reproducibly from a state of fully dispersed nanoparticles to that of a colloidal gel and back. The surface of silica nanoparticles is coated with various amino silanes to identify a silane capable of forming a monolayer on the surface of the particles without causing irreversible aggregation. Of the three silanes used in this study, N-[3-(trimethoxysilyl)propyl]ethylenediamine was found to be capable of producing monolayers up to full surface coverage without inducing irreversible aggregation of the nanoparticles. At near full surface coverage the electrokinetic behavior of the functionalized silica is completely determined by that of the aminosilane. At acidic pH the ionization of the amino groups provides electrosteric stabilization and the system is fully dispersed. At basic pH, the dispersion state is dominated by the hydrophobic interaction between the uncharged aminosilane chains in the aqueous environment and the system forms a colloidal gel. At intermediate pH values the dispersion state is dominated by the balance between electrostatic and hydrophobic interactions, and the system exists in clusters whose size is determined solely by the pH. The transformation between states of aggregation is reversible and a reproducible function of pH. The rate of gelation can be controlled to be as fast as minutes while deaggregation is much slower and takes several hours to complete.

An experiential avoidance conceptualization of depressive rumination: three tests of the model.

This study examined an experiential avoidance conceptualization of depressive rumination in 3 ways: 1) associations among questionnaire measures of rumination, experiential avoidance, and fear of emotions; 2) performance on a dichotic listening task that highlights preferences for non-depressive material; and 3) psychophysiological reactivity in an avoidance paradigm modeled after the one used by Borkovec, Lyonfields, Wiser, and Deihl (1993) in their examination of worry. One hundred and thirty-eight undergraduates completed questionnaire measures and participated in a clinical interview to diagnose current and past episodes of depression. Of those, 100 were randomly assigned to a rumination or relaxation induction condition and participated in a dichotic listening task, rumination/relaxation induction, and depression induction. Questionnaire measures confirmed a relationship between rumination status and avoidance; however, no significant effects were found in the dichotic listening task. Psychophysiological measures indicated no difference in physiological response to a depression induction among high ruminators (HR). However, low ruminators (LR) in the relaxation condition exhibited a larger IBI response than LR in the rumination condition. Overall, these results provide partial support for an avoidance conceptualization of depressive rumination. Implications of these findings are discussed.

Surrogate pregnancy: a guide for Canadian prenatal health care providers.

Providing health care for a woman with a surrogate pregnancy involves unique challenges. Although the ethical debate surrounding surrogacy continues, Canada has banned commercial, but not altruistic, surrogacy. In the event of a custody dispute between a surrogate mother and the individual(s) intending to parent the child, it is unclear how Canadian courts would rule. The prenatal health care provider must take extra care to protect the autonomy and privacy rights of the surrogate. There is limited evidence about the medical and psychological risks of surrogacy. Whether theoretical concerns about these risks are clinically relevant remains unknown. In the face of these uncertainties, the prenatal health care provider should have a low threshold for seeking obstetrical, social work, ethical and legal support.

Fever in term labour.

OBJECTIVES: To determine the antecedents, outcomes, and effects of treatment of fever commencing during term labour without prolonged rupture of membranes (ROM). METHODS: A retrospective database and chart review sought associations between maternal, fetal, and labour variables and fever by comparing women whose membranes had been ruptured for less than 24 hours and who were febrile with those who were not. The strength of significant associations was then compared between febrile women who received acetaminophen or antibiotics and febrile women who did not. RESULTS: We found 16 322 control subjects and 161 cases. On multivariable analysis, fever was associated with epidural analgesia (adjusted odds ratio [AOR] 5.5; 95% confidence interval [CI], 4.0-7.0), length of stage 2 (AOR 1.003 per minute; 95% CI, 1.001-1.005), length of ROM (AOR 1.15 per hour; 95% CI, 1.10-1.20), meconium in the amniotic fluid (AOR 1.7; 95% CI, 1.2-2.2), intervention for nonreassuring electronic fetal monitoring (EFM) (AOR 5.2; 95% CI, 4.4-6.0), intervention for failure to progress in labour (AOR 3.0; 95% CI, 2.1-3.9), and neonatal intensive care unit (NICU) admission (AOR 5.7; 95% CI, 5.1-6.3). A nonstatistically significant trend toward a decrease in failure to progress with acetaminophen administration was noted. CONCLUSIONS: Fever during labour is associated with longer labour, longer ROM, and use of epidural analgesia. For a given length of labour, women with fever are more likely to experience intervention for failure to progress, intervention for nonreassuring EFM, and infant NICU admission.