Sulfinylated azadecalins act as functional mimics of a pollen germination stimulant in Arabidopsis pistils

Polarized cell elongation is triggered by small molecule cues during development of diverse organisms. During plant reproduction, pollen interactions with the stigma result in the polar outgrowth of a pollen tube, which delivers sperm cells to the female gametophyte to effect double fertilization. In many plants, pistils stimulate pollen germination. However, in Arabidopsis, the effect of pistils on pollen germination and the pistil factors that stimulate pollen germination remain poorly characterized. Here, we demonstrate that stigma, style, and ovules in Arabidopsis pistils stimulate pollen germination. We isolated an Arabidopsis pistil extract fraction that stimulates Arabidopsis pollen germination, and employed ultra-high resolution electrospray ionization (ESI), Fourier-transform ion cyclotron resonance (FT-ICR) and MS/MS techniques to accurately determine the mass (202.126 Da) of a compound that is specifically present in this pistil extract fraction. Using the molecular formula (C10H19NOS) and tandem mass spectral fragmentation patterns of the m/z (mass to charge ratio) 202.126 ion, we postulated chemical structures, devised protocols, synthesized N-methanesulfinyl 1- and 2-azadecalins that are close structural mimics of the m/z 202.126 ion, and showed that they are sufficient to stimulate Arabidopsis pollen germination in vitro (30 μm stimulated approximately 50% germination) and elicit accession-specific response. Although N-methanesulfinyl 2-azadecalin stimulated pollen germination in three species of Lineage I of Brassicaceae, it did not induce a germination response in Sisymbrium irio (Lineage II of Brassicaceae) and tobacco, indicating that activity of the compound is not random. Our results show that Arabidopsis pistils promote germination by producing azadecalin-like molecules to ensure rapid fertilization by the appropriate pollen.

Changes in cognitive-emotional and physiological symptoms of depression following STN-DBS for the treatment of Parkinson's disease

BACKGROUND AND PURPOSE

Subthalamic nucleus deep brain stimulation (STN-DBS) has been shown to have beneficial effects on the motor features of Parkinson's disease (PD), but its impact on non-motor symptoms, most notably mood, has not been fully explored.

METHODS

In the first study to independently compare the emotional-cognitive and somatic/physiological symptoms of depression, we examined mood differences in 17 bilateral STN-DBS and 22 matched non-surgical PD patients at baseline and 6 months.

RESULTS

The STN-DBS group reported higher levels of depression at baseline with significant endorsement of physical symptomatology. Postoperatively, no significant between-group differences in physical symptoms of depression were found. In contrast, a significant group by time interaction for cognitive-emotional symptoms of depression was found, with the STN-DBS group reporting an increase in psychological symptoms of distress. The STN-DBS group also reported an increase in anxiety following surgery. The suicide rate of 5% found in our study is consistent with other postoperative studies in PD. The impact of changes in levodopa and psychotropic medication are also explored.

CONCLUSIONS

Preliminary results suggest that the motor improvement often observed in patients with PD following bilateral STN-DBS may be partially offset by an increase in affective-cognitive symptoms of depression.

Heterotopic pregnancy

Heterotopic pregnancy is a life-threatening condition. A recent case at our institution prompted a systematic review of the literature from 2005 to 2010. In the majority (71%) of cases reviewed, risk factors for a heterotopic pregnancy were present. However, in several instances (33%), previous sonographic reports of a normal intrauterine pregnancy gave false reassurance. These results highlight the complexity of diagnosis. In addition, our findings were compared with two previous reviews covering cases from 1971 to 2004. This comparison highlighted two important trends: first, the increasing role of ultrasound in the definitive diagnosis of a heterotopic pregnancy, and second, the development of conservative approaches to management. Medical knowledge and technology may be improving, but ultimately, even in the presence of a known intrauterine pregnancy, the simple dictum 'think ectopic' must not be forgotten.