CARDIOVASCULAR JOURNAL OF AFRICA • Vol 24, No 1, January/February 2013
286
AFRICA
factors that damage the structure of DNA. Experimental evidence
and emerging clinical data suggest that the HMG CoA reductase
inhibitors may exert their beneficial effects in patients with coronary
artery disease (CAD) by reducing cellular senescence and preventing
apoptosis.
Aim:
We investigated the effect of prior statin therapy on leucocyte
telomere length and the interaction with markers of inflammation,
oxidative stress and cellular apoptosis.
Methods
: Consecutive patients below the age of 45 years admitted
to a tertiary cardiac unit were recruited following confirmation of
obstructive CAD on angiography. A population-based, randomly
selected, matched, healthy control group who were statin naïve were
also studied. Apoptotic activity in peripheral blood mononuclear
cells was determined using the Caspase-Glo
®
3/7, 8 and 9 assays.
Oxidative stress was assessed with athiobarbituric acid assay,
which measures the lipid peroxidation end-product malondialde-
hyde. Leukocyte telomere length was measured with a quantitative
PCR-based technique and calculated as the ratio of telomere repeats
to single-copy gene copies (T/S ratio).
Results:
The mean duration of statin therapy in patients was 31
months. Lipid peroxidation was significantly elevated in patients
compared to controls [median/interquartile range 0.0060 (0.0030–
0.0140) cases, 0.0035 (0.0025–0055) controls,
p
<
0.009]. Caspase
8, an initiator of apoptosis activated by the extrinsic pathway, was
significantly reduced in the cases. Telomere length was signifi-
cantly longer in the cases [cases 0.71 (0.69–0.73), controls 0.67
(0.63–0.70),
p
<
0.001]. There was no significant difference in LDL
cholesterol and hsCRP levels between the groups.
Conclusion:
Unrelated to the lipid-lowering, anti-inflammatory and
anti-oxidant effects, chronic statin therapy was associated with longer
telomere length, a marker of vascular ageing. This anti-senescent
effect of statin therapy may emerge as a new strategy in the treatment
of atherosclerosis.
980: REGULATION OF CARDIAC HORMONES DURING
ASPHYXIA IN NEONATES: STUDIES IN A PIGLET MODEL
Birgitte S Kousholt
1
, Kasper Kyng
2
, Torjus Skajaa
2
, Tine B Henriksen
2
1
Department of Cardiothoracic and Vascular Surgery, T-research,
Aarhus University, Denmark
2
Department of Paediatrics and Perinatal Research Unit, Aarhus
University, Denmark
Background:
The natriuretic peptides (ANP and BNP) are expressed
in the myocardium and related to cardiac dysfunction. In adults they
are up-regulated in response to cardiac ischaemia and increased wall
stress, as seen in acute coronary syndromes and cardiac failure. Also
in neonates, the peptides are pursued as cardiac biomarkers. However,
the role of a global hypoxic–ischaemic insult in the newborn period
on cardiac natriuretic peptide expression has not been investigated.
We investigated this in a 72-hour piglet model of hypoxic ischaemic
encephalopathy.
Methods
: Eighteen-hour-old piglets were randomly divided into
a control and intervention group. The piglets in the intervention
group were anesthetised and exposed to global hypoxia (45 minutes)
verified by EEG-depression and arterial pH
<
7.0, whereas control
piglets were only anesthetised. The piglets were awakened and
intensively cared for during a total of 72 hours. Blood samples were
drawn after intubation but prior to any hypoxia and after 72 hours,
and natriuretic peptide concentration was analysed. The piglets were
euthanised and regional myocardial biopsies were obtained. These
biopsies were analysed for cardiac expression of natriuretic peptides
and natriuretic peptide receptors by real-time PCR and Western blot.
Results:
The biochemical analyses are being performed and results
are pending.
Conclusion:
In order to validate whether natriuretic peptides can be
used as specific biomarkers of cardiac compromise in neonates, it
will be of value to conclude whether the natriuretic peptide expres-
sion occurs as a result of global hypoxia
per se
or not. Furthermore,
it is of great interest to convey whether the natriuretic peptide expres-
sion is regional and corresponds to plasma values in the same manner
as seen in adults to verify whether parallels can be drawn from the
vast knowledge of natriuretic peptides in adult cardiac disease.
985: DOES CARDIAC MUSCLE RESTORATION OF THE
LEFT VENTRICLE DIFFER FROM THE RIGHT VENTRI-
CLE IN THE NORMAL CANINE HEART? A PASSIVE
STRESS–STRAIN RELATIONSHIP
IN VITRO
STUDY
Lucy Eun
1
, Jae Young Choi
1
, Han Ki Park
2
1
Paediatric Cardiology, Yonsei University Severance Cardiovascular
Hospital, Republic of Korea
2
Cardiovascular Surgery, Yonsei University Severance Cardiovascular
Hospital, Republic of Korea
Background:
Early deterioration of diastolic ventricular func-
tion usually precedes systolic ventricular abnormalities. Normal
cardiac muscle restoration is important for adequate relaxation and
may depend on muscle fibre orientation. The passive stress–strain
relationship as an indicator for cardiac muscle restoration has been
established.
Objective:
The goal of the study was to compare and characterise
the
in vitro
passive stress–strain relationship of the left and right
ventricular muscle in the normal canine heart.
Methods:
Cardiac muscle tissue from four normal canine hearts was
studied. Samples were taken from the ventricular free wall, ventricu-
lar septum and papillary muscles of both left and right ventricles.
Each sample was divided into three blocks and was studied in three
different orientations: longitudinal, radial and circumferential. Each
sample underwent compression under four different strain rate condi-
tions, ranging from 10 to 40/sec. Relaxation of the cardiac muscles
was recorded by multiple sensors for each sample, and stress–strain
loops were calculated from force and displacement data.
Results:
Stress–strain relationships of the left and right ventricles
were significantly different. Stress of the left ventricular free wall and
septum, when measured in the radial and circumferential direction,
was significantly higher than for the same amount of strain applied
on right ventricular muscle. LV stress
=
40.5–60.2 Pascals (mean
=
48.2); RV stress
=
20.1–38.9 Pascals (mean
=
31.2) (
p
<
0.001).
When the longitudinal direction was compared, right ventricular
stress was significantly higher than left ventricular stress under the
same strain conditions, RV stress
=
40.7–80.6 Pascals (mean
=
49.1);
LV stress
=
20.4–40.3 (mean
=
31.2) (
p
<
0.001). Papillary muscle
stress–strain relationship was similar for both ventricles in the longi-
tudinal direction.
Conclusions:
Cardiac muscle restoration is different between the left
and right ventricles in the normal canine heart. LV muscle is more
efficient in the longitudinal direction, while RV muscle is superior in
the radial and circumferential orientations. Measurements of cardiac
restoration may provide new insight on diastolic function.
1193: CHANGES OF CASPASE 3, BCL2, VASCULAR
ENDOTHELIAL GROWTH FACTOR GENE EXPRESSIONS
AFTER HUMAN UMBILICAL CORD BLOOD-DERIVED
MESENCHYMAL STEM CELL TRANSFUSION IN PULMO-
NARY HYPERTENSION RAT MODELS
Young Mi Hong
1
, Kwan Chang Kim
2
, Min-Sun Cho
3
, Yoon Sun
Yang
4
, Wonil Oh
4
, Soo Jin Choi
1
Department of Paediatrics, Ewha Womans University, Seoul, Korea
2
Department of Thoracic and Cardiovascular Surgery, Ewha Womans
University, Seoul, Korea
3
Department of Pathology, Ewha Womans University, Seoul, Korea
4
Biomedical Research Institute, MEDIPOST, Co. Seoul, Korea
Objective
: Pulmonary arterial hypertension (PAH) is difficult to
treat and is characterised by increased pulmonary arterial pressure,
right heart failure and death. PAH has been shown to be refractory to
most of the conventional pharmacological therapies. Human umbili-
cal cord blood-derived mesenchymal stem cells (hUCB-MSCs) are
