Effect of inactivation of Mst1 and Mst2 in the mouse adrenal cortex

Recent conditional knockout of core components of the Hippo signaling pathway in the adrenal gland of mice has demonstrated that this pathway must be tightly regulated to ensure proper development and maintenance of the adrenal cortex. We report herein that the most upstream kinases of the pathway, the mammalian STE20-like protein kinases 1 and 2 (MST1and MST2, respectively), are expressed in the mouse adrenal cortex with MST2 expression being restricted to the zona glomerulosa (zG). To further explore the role of Hippo signaling in adrenocortical cells, we conditionally deleted Mst1/2 in steroidogenic cells using an Nr5a1-cre strain (Mst1flox/flox; Mst2flox/flox; Nr5a1-cre). Our results show that the loss of MST1/2 leads to the premature and progressive accumulation of subcapsular GATA4+, WT1 + adrenal gonadal primordium (AGP)-like progenitor cells starting at 2 months of age without affecting aldosterone and corticosterone secretion. To help us understand this phenotype, microarray analyses were performed on adrenal glands from 2-month-old mutant and control mice. Gene expression analyses revealed that loss of Mst1/2 leads to the overexpression of known downstream target genes (Ajuba, Aqp1, Fn1, Ibsp, Igf1, Igfbp2, Mmp2, Thbs1) of the main effector of Hippo signaling, YAP; and underexpression of genes (Agtr1b, Ecgr4, Hsd3b6, Nr0b1, Tesc, Vsnl1) that are normally specifically expressed in the zG or overexpressed in the zG compared to the zona fasciculata (zF). Together, these results suggest that MST1/2 regulates Hippo signaling activity in the adrenal cortex and that these two kinases are also involved in the fine tuning of zG cell function or differentiation.

Isomorphous crystal structures of chlorodi-acetyl-ene and iododi-acetyl-ene derivatives: simultaneous hydrogen and halogen bonds on carbon-yl

tert-Butyl (5-chloro­penta-2,4-diyn-1-yl)carbamate and tert-butyl (5-iodo­penta-2,4-diyn-1-yl)carbamate are new members of the isostructural family of compounds with the general formula BocNHCH₂CCCCX (X = H, Cl, Br, I). In the crystals of all these di­acetyl­enes, mol­ecules are linked via a bifurcated N—H⋯O hydrogen bond and C—X⋯O halogen bond involving the same carbonyl group.

The crystal structures of tert-butyl (5-chloro­penta-2,4-diyn-1-yl)carbamate, C₁₀H₁₂ClNO₂ (II), and tert-butyl (5-iodo­penta-2,4-diyn-1-yl)carbamate, C₁₀H₁₂INO₂ (IV), are isomorphous to previously reported structures and accordingly their mol­ecular and supra­molecular structures are similar. In the crystals of (II) and (IV), mol­ecules are linked into very similar two-dimensional wall organizations with anti­parallel carbamate groups involved in a combination of hydrogen and halogen bonds (bifurcated N—H⋯O=C and C≡C—X⋯O=C inter­actions on the same carbonyl group). There is no long-range parallel stacking of diynes, so the topochemical polymerization of di­acetyl­ene is prevented. A Cambridge Structural Database search revealed that C≡C—X⋯O=C contacts shorter than the sum of the van der Waals radii are scarce (only one structure for the C≡C—Cl⋯O=C inter­action and 13 structures for the similar C≡C—I⋯O=C inter­action).

Effects of introducing an administrative .05% blood alcohol concentration limit on law enforcement patterns and alcohol-related collisions in Canada

Except for Quebec, all Canadian provinces have introduced administrative laws to lower the permitted blood alcohol concentration (BAC) to .05% or .04% for driving-or having the care of-a motor vehicle. Using linear mixed effects models for longitudinal data, this study evaluates the effect of administrative BAC laws on fatal alcohol related crashes and law enforcement patterns in Canada from 1987 to 2010. Results reveal a significant decrease of 3.7% (95% C.I.: 0.9-6.5%) in fatally injured drivers with a BAC level equal or greater than .05% following the introduction of these laws. Reductions were also observed for fatally injured drivers with BAC levels greater that .08% and .15%. The introduction of administrative BAC laws led neither to significant changes in the rate of driving while impaired (DWI) incidents reported by police officers nor in the probability of being charged for DWI under the Criminal Code.

[The impact of opening a heroin-assisted treatment clinic on the surrounding neighborhood]

OBJECTIVES

Heroin-assisted treatment clinics are currently the focus of a social debate. In spite of the clinics’ effectiveness in reducing illicit opiate use, some decision-makers refuse to set them up because of their possible negative impact. These clinics could attract new drug users into the neighbourhood which could lead to an accumulation of injection debris and to a decrease in the sense of security in the community. This study assesses the impact on some elements observed in the surrounding community following the opening of the Montreal heroin-assisted treatment clinic.

METHODS

Ethnographical walks were taken in order to collect data on the amount of injection debris, street debris and deviant activities. Data were then aggregated on a daily basis and our interrupted time series were analyzed using the segmented regression methodology.

RESULTS

Results show that the opening of the clinic was followed by a significant drop in the amount of injection and street debris. This reduction appears proportional to the number of clinic participants.

CONCLUSION

The Montreal heroin-assisted treatment clinic did not produce any negative impact on the surrounding community. In fact, implementation of this kind of clinic was followed by a positive effect on the neighbourhood. In addition to the ethnographical walks, further studies should include surveys in order to estimate the impact of heroinassisted treatment clinics on residents’ sense of security. Even if there appears to be a positive impact, it is possible that the mere presence of these clinics negatively affects community members’ sense of security.

[Evaluation of a police strategy for road safety in Quebec: the strategy of the Quebec Association of Police Chiefs]

OBJECTIVE

To estimate the effect on collisions of a police traffic safety strategy carried out between January and December 2007, in the province of Quebec, Canada.

CONTEXT

This strategy was implemented by several key players (Société de I'Assurance Automobile du Québec, Sûreté du Québec, Montreal Police Department and 34 other municipal police organizations) and targeted the leading causes of traffic casualties such as drinking and driving, speeding and not wearing a seat belt. The strategy has two main components: 1) joint law enforcement operations in which all the police organizations take part, and 2) police organizations targeting local traffic safety problems. Media campaigns supported all operations.

INTERVENTION

Over the intervention period, traffic citations issued for speed limit violations, not fastening the seat belt and running the red light or a stop sign increased from 2006 rates by 27, 33 and 8%, respectively. The Société de I'Assurance Automobile du Québec spent more than $5 million in mass media campaigns.

RESULTS

According to our results, the strategy was associated with decreases varying between 14 and 36% in collisions with serious injuries. In spite of evidence of downward trends for the period under investigation, neither fatal nor minor injury collisions were significantly affected by introduction of the strategy.

CONCLUSION

Police programs characterized by a substantial increase in the distribution of traffic citations and supported by mass media campaigns represent an effective strategy to prevent traffic casualties.