Oocyte maturation is dependent on a complex program of morphological, ultrastructural, and biochemical signaling events, and if disrupted could lead to decreased fertility and population decline. The in vitro sensitivity of amphibian oocytes and oocyte maturation to plant growth factor and widely used hormonal herbicide, 2,4-dichlorophenoxyacetic acid (2,4-D), was examined in this study to determine its potential impact on early development and possible contribution to the global amphibian decline. Progesterone, which acts through a membrane receptor, triggers meiotic maturation in full grown (stage VI) Xenopus oocytes, characterized by cytoskeletal reorganization, nuclear dissolution, chromosome condensation, and spindle formation. Biochemically, the Mos/MAPK/MPF signaling pathway is activated, in part dependent on translational activation of specific maternal mRNAs such as c-Mos. Light microscopy revealed unusual asymmetric morphotypes in oocytes exposed to 2,4-D alone characterized by a white spot and bulge, termed coning, in the animal pole where the germinal vesicle (nucleus) persisted intact. Treatment of oocytes with cytochalasin B, a microfilament inhibitor, blocked these morphotypes but nocodazole, a microtubule depolymerizing agent, did not. Confocal microscopy showed that 2,4-D, itself, caused substantial depolymerization of perinuclear microtubules. Importantly, 2,4-D blocked progesterone-induced maturation as measured by the lack of nuclear breakdown, confirmed by the lack of Mos expression, MPF activation, and cytoplasmic polyadenylation of cyclin B1 mRNA. However, Western blot analysis and U0126 inhibitor studies showed that 2,4-D, either alone or in the presence of progesterone, induced MAPK phosphorylation through MAPKK. These results show that 2,4-D disrupts oocyte cytoskeletal organization and blocks maturation while stimulating an independent MAPK signaling pathway.

IntroductionMost US studies on asthma prevalence have been conducted in urban areas, and few have assessed the prevalence of asthma among residents of rural areas versus urban areas. The objective of this study was to compare the prevalence of asthma among adults living in metropolitan versus nonmetropolitan counties in Montana.

Evidence-based clinical guidelines emphasize providing asthma self-management education (ASME) to patients at multiple points of care. However, clinical and population-based studies indicate that the provision of ASME is inconsistent. Between 2006 and 2008, the Montana Department of Public Health and Human Services (DPHHS) conducted the Asthma Call Back Survey (ACS), a telephone survey of a representative sample of adults with asthma in the state (N = 767). Based on a control scale algorithm, 54% of respondents with asthma were well controlled and 46% were either not well controlled or were very poorly controlled. Adults with uncontrolled asthma were more likely than adults with well-controlled asthma to report seeing a health care provider in the past year either through a routine checkup for asthma (adjusted odds ratio [AOR], 7.4; 95% confidence interval [CI], 4.8-11.5), to have an urgent care or emergency department visit for asthma (AOR, 18.3; 95% CI, 6.5-51.5), or to have ever taken a class to self-manage asthma (AOR, 3.0; 95% CI, 1.4-6.6). Respondents with uncontrolled asthma were somewhat more likely to use a peak flow meter (AOR, 1.8; 95% CI, 1.2-2.8) and to have been advised to change aspects of their home, work, or school to improve their asthma (AOR, 1.7; 95% CI, 1.1-2.6) compared with those with well-controlled asthma. Adults with uncontrolled asthma were no more likely than adults with well-controlled asthma to report ever being given an asthma management plan (AOR, 1.7; 95% CI, 1.0-2.7) or instructed on how to recognize the early signs of an asthma attack (AOR, 1.3; 95% CI, 0.8-2.1). Our findings suggest that Montana providers may be missing key clinical opportunities to provide and reinforce ASME, particularly among those with uncontrolled asthma. Strategies are needed to increase asthma control and use of ASME.

No abstract

No abstract