 Characteristics
of Heparin-Induced Platelet Aggregates in Chronic Hemodialysis with Long-Term
Heparin Use.
Reference: Haemostasis 2000;30(5):249-257.
This study investigated the usefulness of a new platelet aggregometer with
a laser-scattering
method for detection of heparin-induced small platelet aggregates in chronic
hemodialysis
patients. Using this device, small platelet aggregates (particle size 9-25
?m) were detectable, but
these aggregates could not be detected using a conventional light transmittance
aggregometer.
The laser-scattering intensity of the small aggregates was increased with
an increasing dosage of
heparin as agonist. These aggregates were disaggregated by heparin neutralization
with protamine
sulfate. Induction of small platelet aggregates by heparin was inhibited
by preincubation with
nafamostat mesilate, a synthetic protease inhibitor, and cilostazol, a
platelet phosphodiesterase
inhibitor, but not by the therapeutic doses of aspirin or argatroban, a
selective thrombin inhibitor.
The dialysis patients with long-term heparin use could be divided into
two groups: responders to
heparin, who formed small aggregates with a scattering intensity over 0.51
x 10(5) V after
addition of 0.5 IU/ml of heparin obtained from normal platelet-rich plasma
without inductor, and
nonresponders, who showed an intensity under 0.51 x 10(5) V. The rate of
heparin responders
among dialysis patients was significantly higher than the rate among normal
subjects.
Heparin-induced small aggregates were detected in 13 (36.1%) of 36 normal
subjects with no
history of heparin infusion and in 37 (62.7%) of 59 dialysis patients who
received heparin
anticoagulation during each dialysis session. Dialysis patients with coronary
heart disease did not
have a significantly higher rate of heparin responders than patients without
complications. There
was no significant difference in the positivity rate between cases complicated
by diabetes and
those without diabetes. In patients who had more than 2 episodes of thrombotic
occlusions of an
arteriovenous fistula, the rate of responders and the enhancement of scattering
intensity of small
aggregates by heparin were significantly increased compared with these
in patients without
occlusions during the preceding 2 years. Moreover, dialysis patients with
a positive heparin
response showed a marked increase in scattering intensity of small aggregates
after heparin
infusion in each dialysis session. Determination of the response to heparin
prior to heparin use in
dialysis patients with repeated thromboembolic complication may be useful
in choosing
anticoagulant regimens.
Cilostazol,
a phosphodiesterase inhibitor, improves insulin sensitivity in the Otsuka
Long-Evans Tokushima Fatty Rat, a model of spontaneous NIDDM.
Reference: Diabetes Obes Metab 1999;1(1):37-41.
AIM: Angiotensin converting enzyme inhibitors and alpha1-adrenergic blockers
improve insulin
sensitivity, the mechanism of which was considered, at least in part, to
be due to the increased
blood flow to muscle. The present study aimed to clarify whether cilostazol,
a phosphodiesterase
inhibitor, improves insulin sensitivity in a model of spontaneous non-insulin
dependent diabetes
mellitus (NIDDM), Otsuka Long-Evans Tokushima Fatty (OLETF) rat. METHODS:
OLETF
rats were divided into the two groups at the age of 16 weeks: the cilostazol-supplemented
group
(cilostazol 40 mg/kg/day) and the normal-diet group. As a non-diabetic
control, we used
Long-Evans-Tokushima-Otsuka rats (non-diabetic rats). Oral glucose tolerance
test and
hyperinsulinemic euglycemic clamp was performed at the ages of 23 and 25
weeks, respectively.
Serum levels of lipids and leptin were measured. RESULTS: Body weight and
abdominal fat was
increased in OLETF rats but cilostazol supplementation did not alter them.
Insulin sensitivity, as
measured by the hyperinsulinemic euglycemic clamp technique, was significantly
decreased in
OLETF rats (glucose infusion rate: 73.5 +/- 10.0 vs. 41.5 +/- 9.8 micromol/min/kg
body weight,
p < 0.01). Cilostazol supplementation improved insulin sensitivity partially
but significantly 51.0
+/- 5.7 micromol/min/kg body weight, p < 0.05) in OLETF rats at 25 weeks
of age, although it
did not decrease serum levels of glucose, lipids or leptin. However, this
effect was not observed
in non-diabetic rats. CONCLUSION: Cilostazol, which is used in diabetic
patients for the
treatment of obstructive disease of artery, is expected to have a beneficial
effect on insulin
sensitivity in NIDDM.
Use
of arteriography for the initial evaluation of patients with intermittent
lower limb claudication.
Reference: Sao Paulo Med J 2001;119(2):59-61.
CONTEXT: Many patients with intermittent claudication continue to be forwarded
to the
vascular surgeon for initial evaluation after arteriography has already
been accomplished.
OBJECTIVE: The main objective of this work was to analyze the usefulness
and the need for this
procedure. TYPE OF STUDY: Retrospective study. SETTING: The patients were
divided into
two groups: Group 1, with the arteriography already performed and Group
2 without the initial
arteriography. PARTICIPANTS: One hundred patients with intermittent claudication
were
retrospectively studied. Other specialists had forwarded them for the first
evaluation of
intermittent claudication, without any previous treatment. MAIN MEASUREMENTS:
All
patients were treated clinically for at least a 6-month period. The total
number of arteriographies
performed in the two groups was compared and the need and usefulness of
the initial
arteriography (of Group 1) was also analyzed. RESULTS: The evolution was
similar for both
groups. The total number of arteriographies was significantly higher in
Group 1 (Group 1 with 53
arteriographies vs. Group 2 with 7 arteriographies). For this group, it
was found that
arteriography was only useful in five cases (10%), because the surgeries
were based on their
findings. However, even in those cases, no need for arteriography was observed,
as the
procedure could have been performed at the time of surgical indication.
CONCLUSION: There
are no indications for arteriography in the early evaluation of patients
with intermittent
claudication, because it does not modify the initial therapy, independent
of its result. In cases
where surgical treatment is indicated, this procedure should only be performed
prior to surgery.
Quality
of life in patients with intermittent claudication using the world health
organisation (who) questionnaire.
Eur J Vasc Endovasc Surg 2001;21(2):118-22.
Objective: to assess quality of life (QOL) in patients with intermittent
claudication. Design: a
prospective, open study. Material and method: one hundred and fifty-one
consecutive claudicants
(100 men, 51 women), and 161 healthy controls (70 men and 91 women) completed
an adapted
version of the World Health Organisation Quality of Life Assessment Instrument-100.
Results:
patients scored significantly worse on the domains Physical health and
Level of independence, as
well as on the facets Pain and discomfort, Energy and fatigue, Mobility,
Activities of daily living,
Dependence on medication and treatments, Working capacity, Negative feelings,
Recreation and
leisure and Overall QOL and general health. Increasing disease to incapacitating
claudication
affected only the facet Mobility and the domain Level of independence.
Conclusion: QOL in
patients with intermittent claudication is reduced in many aspects. Where
co-morbidity seems to
affect QOL strongly, the effect of walking distance on QOL might be small.
These findings may
justify a reserved attitude towards invasive, even minimally invasive treatment
of these patients.
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Volume
4, Number 4:April 2001
