ABSTRACT
Chronic obstructive pulmonary disease (COPD) affects millions of people worldwide, resulting in morbidity, mortality, and substantial utilization of health care resources. This review focuses on the epidemiology of COPD, management strategies, and the health and economic impact of this condition in North Carolina.
Subject(s)
Pulmonary Disease, Chronic Obstructive/prevention & control , Pulmonary Disease, Chronic Obstructive/therapy , Humans , North Carolina/epidemiology , Pulmonary Disease, Chronic Obstructive/epidemiology , Pulmonary Disease, Chronic Obstructive/pathology , Risk FactorsABSTRACT
Injections of the angiotensin(1-7) [Ang(1-7)] antagonist [d-Ala7]-Ang(1-7) into the nucleus of the solitary tract (NTS) of Sprague-Dawley rats reduce baroreceptor reflex sensitivity (BRS) for control of heart rate by approximately 40%, whereas injections of the angiotensin II (Ang II) type 1 receptor antagonist candesartan increase BRS by 40% when reflex bradycardia is assessed. The enzyme angiotensin-converting enzyme 2 (ACE2) is known to convert Ang II to Ang(1-7). We report that ACE2 activity, as well as ACE and neprilysin activities, are present in plasma membrane fractions of the dorsomedial medulla of Sprague-Dawley rats. Moreover, we show that BRS for reflex bradycardia is attenuated (1.16 +/- 0.29 ms mmHg-1 before versus 0.33 +/- 0.11 ms mmHg-1 after; P < 0.05; n = 8) 30-60 min following injection of the selective ACE2 inhibitor MLN4760 (12 pmol in 120 nl) into the NTS. These findings support the concept that within the NTS, local synthesis of Ang(1-7) from Ang II is required for normal sensitivity for the baroreflex control of heart rate in response to increases in arterial pressure.
Subject(s)
Angiotensin-Converting Enzyme Inhibitors/pharmacology , Baroreflex/drug effects , Heart Rate/drug effects , Imidazoles/pharmacology , Leucine/analogs & derivatives , Peptidyl-Dipeptidase A/metabolism , Solitary Nucleus/physiology , Angiotensin-Converting Enzyme 2 , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Animals , Blood Pressure/drug effects , Blood Pressure/physiology , Imidazoles/administration & dosage , Leucine/administration & dosage , Leucine/pharmacology , Male , Medulla Oblongata/enzymology , Medulla Oblongata/metabolism , Membranes/drug effects , Membranes/metabolism , Neprilysin/metabolism , Phenylephrine/pharmacology , RNA, Messenger/biosynthesis , RNA, Messenger/genetics , Rats , Rats, Sprague-DawleyABSTRACT
The partially conserved Mad3/BubR1 protein is required during mitosis for the spindle assembly checkpoint (SAC). In meiosis, depletion causes an accelerated transit through prophase I and missegregation of achiasmate chromosomes in yeast [1], whereas in mice, reduced dosage leads to severe chromosome missegregation [2]. These observations indicate a meiotic requirement for BubR1, but its mechanism of action remains unknown. We identified a viable bubR1 allele in Drosophila resulting from a point mutation in the kinase domain that retains mitotic SAC activity. In males, we demonstrate a dose-sensitive requirement for BubR1 in maintaining sister-chromatid cohesion at anaphase I, whereas the mutant BubR1 protein localizes correctly. In bubR1 mutant females, we find that both achiasmate and chiasmate chromosomes nondisjoin mostly equationally consistent with a defect in sister-chromatid cohesion at late anaphase I or meiosis II. Moreover, mutations in bubR1 cause a consistent increase in pericentric heterochromatin exchange frequency, and although the synaptonemal complex is set up properly during transit through the germarium, it is disassembled prematurely in prophase by stage 1. Our results demonstrate that BubR1 is essential to maintain sister-chromatid cohesion during meiotic progression in both sexes and for normal maintenance of SC in females.
