41
Abstracts
P R O B E
• V o l . L I I I • N o . 3 • A p r – J u n 2 0 1 4
Neurology
Brain Natriuretic Peptide Protects Against
Hyperreactivity of Human Asthmatic
Airway Smooth Muscle via an Epithelial Cell
Dependent Mechanism
Calzetta L, et al
A
m J Respir Cell Mol Biol
. 2014;50(3):493–501.
The aim of our study was to investigate the influence of
brain natriuretic peptide (BNP) on airway smooth muscle
cells (ASMs) obtained from asthmatic and healthy donors
and to identify the mechanisms involved in BNP-mediated
relaxation.
The contractile response of ASM cells was microscopically
assessed in vitro in the presence of 1 µM BNP or with
supernatant from human bronchial epithelial (BEAS-2B)
cells pretreated with 1 µM BNP. We investigated the role
of muscarinic M2-receptors and inducible nitric oxide
synthase (iNOS), quantified the release of acetylcholine
and nitric oxide (NO) and assessed the gene/protein
expression of iNOS and myosin phosphatase target subunit
1 (MYPT1).
Supernatant from BEAS-2B cells treated with BNP reduced
the hyperreactivity of asthmatic ASM cells by shifting
the potency of histamine by 1.19-fold, but had no effect
in normal ASM cells. BNP was not effective directly
on ASM cells. Blocking muscarinic M2-receptor and
iNOS abolished the protective role of supernatant from
BEAS-2B treated with BNP. BNP stimulated the release of
acetylcholine (210.7 ± 11.1%) from BEAS-2B cells that in
turn increased MYPT1 and iNOS gene/protein expression
and enhanced NO levels in asthmatic ASM supernatant
(35.0 ± 13.0%).
BNP protects against bronchial hyperresponsiveness via
an interaction between respiratory epithelium and ASM in
subjects with asthma.
Urinary Calculi and an Increased Risk of Stroke:
A Population-based Follow-up Study
Chung SD, et al
BJU Int
. 2012;110(11 Pt C):E1053–E1059.
Although early studies failed to detect an association
between urinary calculi (UC) and subsequent
cardiovascular risk, there is growing evidence among more
recent research supporting this association with some
studies more specifically suggesting that stroke is a major
concern for UC sufferers.
However, none of the studies that have investigated the
relationship between urinary calculi (UC) and stroke were
able to detect an association at a significant level.
We used data sourced from the Taiwan Longitudinal
Health Insurance Database 2000. All the subjects were
tracked for a 5-year period beginning from their index
ambulatory care visits, and those who subsequently had a
stroke identified.
During the 5-year follow-up period, the incidence rate of
stroke was 1.78 per 100 person-years in patients with UC
and 1.25 per 100 person-years in patients without UC.
After adjusting for hypertension, diabetes, hyperlipidemia,
cardiovascular disease, urbanization level, gout, and obesity,
patients with UC were more likely to have had a stroke than
those without UC during the 5-year follow-up period
(
P
< .001).
Our results suggest that there is an increased risk of stroke
during the first 5 years after a diagnosis of UC.
