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Plasma P selectin preeclampsia and
(GMP-140) and glycocalicin are eclampsia: Their significances
elevated in
Abdul HaUm, MB, BS," Naohiro Kanayama, PhD," Fanad E1 Maradny, MS," Akira Nakashima, MD," A.B. Bhuiyan, b Selina Khatun, MB, BS, ~ and Toshihiko Terao, PhD a
Hamamatsu, Japan, and Dhaka, Bangladesh
OBJECTIVE: We measured the concentrations of plasma P selectin (or GMP-140) and glycocalicin in preeclamptic and eclamptic women. Correlations between these two parameters and blood pressures, platelet counts, or plasma thrombin-antithrombin complex values were evaluated. STUDY DESIGN: By use of enzyme-linked immunosorbent assays we measured the plasma GMP-140 and glycocalicin levels in normal pregnancies (n = 10) and preeclamptic (n = 10) and eclamptic (n = 20) pregnancies. The glycocalicin index was calculated as follows: (glycocalicin x [250 x 106/ml])/(Individual platelet counts). Correlations between plasma GMP-140, glycocalicin, glycocalicin index values, blood pressures, platelet counts, and plasma thrombin-antithrombin complex values were analyzed. RESULTS" Plasma GMP-140 levels were found to be significantly elevated in preeclamptic (p < 0.0005) and eclamptic cases (p < 0.0001) compared with normotensive controls. Plasma glycocalicin (p = 0.01, 0.007) and glycocalicin index (p = 0.005, 0.002) values were also markedly elevated in preeclamptic and eclamptic patients compared with normal pregnant patients. Significant correlations between platelet counts or plasma thrombin-antithrombin complex levels and their corresponding plasma GMP-140 and glycocalicin and glycocalicin index values have been found in preeclamptic and eclamptic cases. However, blood pressures had correlations with GMP-140, glycocalicin, and glycocalicin index values in eclamptic cases. CONCLUSIONS: We demonstrated an elevation of plasma GMP-140 and platelet glycocalicin in preeclampsia and eclampsia. This study also reflects the usefulness of glycocalicin as a marker of platelet activation or turnover and endothelial dysfunction in these diseases. (AM J OBSTET GYNECOL 1996;174:272-7.)
Key words: P selectin (GMP-140), glycocalicin, preeclampsia-eclampsia, platelet activation, endothelial cell activation
Preeclampsia-eclampsia was described as a state of
platelet hyperactivity and hypercoagulability?' ~ Cellular activation 3, 4 and endothelial dysfunction 5 were also sug-
gested to participate in the pathogenesis of this disease.
There is increasing evidence that endothelial cell injury and altered endothelial cell function may play an impor- tant role in the pathogenesis of preeclampsia and ec-
lampsia. ~ The hypothesis of endothelial dysfunction is also supported by the increased level of factor VIII-re- lated antigen and fibronectin and an imbalance of tissue plasminogen activator and its inhibitors, vasoconstrictors, and vasodilators that occurs in this disease. 6 Elevated plasma thrombin-antithrombin complexes and a de-
crease in plasma antithrombin III activity were reported
From the Departments of Obstetrics and Gynecology, Hamamatsu Uni- versity School of Medicine, ~ and Dacca Medical College and Hospital. b Received for publication December 13, 1994; revised April 14, 1995; accepted May 15, 1995. Reprint requests: Abdul Halim, MB, BS, Department of Obstetrics and Gynecology, Hamamatsu University School of Medicine, 3600 Handa- eho, Hamamatsu 431-31, Japan. Copyright © 1996 by Mosby-Year Book, Inc. 0002-9378/96 ~5.00+ 0 6/1/66316
in preeclampsia v and eclampsia, a A characteristic fall in
platelet counts occurs because of the increased consump-
tion of platelets in preeclampsia. ~
P selectin, or GMP-140, is a member of a family of cell
adhesion receptors, termed selectins, that mediate cellu- lar interactions. 10" H It is expressed in the c~ granules of
platelets 12 and the Weibel-Palade bodies of endothelial cells. 13 The soluble forms of surface membrane glycopro- teins have been identified as markers for cellular activity in which the receptors are involved. 1~ Dunlop et al. ~4
demonstrated that GMP-140 is secreted from the acti- vated platelets and circulates in plasma as a soluble and functional form.
Platelet glycocalicin is a carbohydrate-rich hydrophilic fragment that can be rapidly cleaved from the extramem- branous portion of the c~ chain of glycoprotein Ib by
various proteases such as calpain, plasmin, trypsin, and elastase. ~ It has been suggested that glycocalicin circu- lates in plasma and that its plasma level is dependent on the platelet counts that are the base for the glycocalicin index. 16 The glycocalicin index values were found to be elevated in hemodialyzed patients and patients with liver cirrhosis, reflecting an increased platelet turnover or an
272
I
Volume 174, Number 1, Part 1 HNim et al. 273 AmJ Obstet Gynecol
Table I. Characteristics of normal pregnancies and preeclamptic and eclamptic cases included in this study
Edamptic cases Preeclamptic cases Normal pregnancies (n = 20 ) (n = 10) (n = 10)
Age (yr) 23 --- 4.4* 24 -+ 4.7* 25 -+ 5 Parity (range and No. ofprimiparas) 0-2 (17) 0-2 (8) 0-3 (6) Weeks of gestation 37 --- 4.4* 37.6 -+ 4.7* 38.3 -+ 2.4 Systolic blood pressure (mm Hg) 161 _+ 17.8-~ 162 -+ 14.1 t 109 _+ 5.7 Diastolic blood pressue (ram Hg) 108 _ 13.0t 115 + l l .2t 69 + 6.2 Birth weight (gm) 2460 -+ 490]- 2610 -+ 4095 3320 -+ 278 Platelet counts (×107/ml) 23.9 -4- 6.7t 25.5 _+ 4.1+ 33.4 _+ 3.5 Plasma thrombin-antithrombin complex 41.3 -+ 18.0t 17.2 - 9.3t 5.1 + 2.3
(ng/ml)
All values are mean -+ SD except parity. Significance as compared with normal pregnancies by Mmm-Whimey Utest. *Not significant, p > 0.05. +p < 0.001. ++p< 0.0l.
abnormal proteolysis) r It has been also suggested that
glycocalicin is a useful platelet marker that reflects plate- let damage and a possible platelet dysfunction. 17 Because
glycocalicin could act as a circulating inhibitor of throm-
bin action on platelets, it may also serve as a platelet marker of different characteristics. Sandwich enzyme-
linked immunsorbent assays (with monoclonal antibod- ies) were recently developed to quantify the plasma con- centration of GMP-140 is and glycocalicin) 9
Taking all the above in consideration, we assumed that the endothelial activation or dysfunction and platelet
activation or turnover occurs simultaneously in pre-
eclampsia-eclampsia. Therefore this study was under- taken to determine the concentration of GMP-140 and platelet glycocalicin in the plasma of eclamptic and
preeclamptic patients in comparison with normotensive controls. Correlations between these values and their cor- responding blood pressure, platelet counts, and plasma thrombin-antitbrombin complex levels were evaluated to
understand their significance.
Material and methods
This was a collaborative study between Dhaka Medical College Hospital, Bangladesh, and Hamamatsu Univer-
sity School of Medicine, Japan. It was approved by the research committees of the appropriate institutions.
Patients. Proper consents from patients or patients' guardians (in case of eclamptic patients) were obtained.
We studied 20 eclamptic patients admitted to Dacca Medical College Hospital, Bangladesh, between May 1992
and January 1994. All the eclamptic patients essentially had the criteria for preeclampsia and in addition had at least one episode of eclamptic convulsions either in the
hospital or at home. There was no other reason for the onset of seizures in the eclamptic patients. All preeclamp- tic patients had a blood pressure >140/90 mm Hg (de- tected on at least two occasions) and proteinuria (_>300 mg/24 hours). None of them had hypertension before 20 weeks of pregnancy. Table I shows the important charac-
teristics of all the patients included in this study. Ten normal pregnancies (as normotensive controls) and 10 preeclamptic patients were enrolled in this study from
the patients admitted at Hamamatsu University Hospital from January 1992 to March 1994. The platelet counts in preeclamptic and eclamptic patients were 25.5 _+_ 4.1 and 23.9 _+ 6.7 × 107/ml (mean + SD), respectively. All cases
were matched for age (range 16 to 32 years), parity (range 0 to 2), and weeks of gestation (range 33 to 40 weeks). All
cases were singleton pregnancies except two cases (one
normal and one eclamptic) that were twin pregnancies. Two cases (one preeclamptic and one eclamptic) had the
HELLP syndrome (hemolysis, elevated liver enzymes, and low platelets). All cases complicated by essential hyperten- sion, diabetes, chronic renal disease, platelet disorders, maternal or fetal infection, autoimmune disorders, and epilepsy were exlcuded from this study.
Blood was drawn in the morning in all cases except
three eclamptic patients where it was done at a different time during admission through the emergency depart-
ment of the hospital. None of the eclamptic women had
received magnesium sulfate or antiplatelet therapy be-
fore blood collection. Only two of the eclamptic patients
were in labor. Peripheral venous blood samples were col-
lected in 3.8% sodium citrate solution (1:9 volume ratio) immediately after the measurement of blood pressures by
KorotkofFs first and fifth sounds with the patient in the recumbent position. Plasma of eclamptic patients (n = 20) was prepared in Dhaka Medical College and kept
at -40 ° C until transferred to Japan by air (within 16 hours) on dry ice (at -40 ° C). Plasma samples fiom pa- tients at Hamamatsu University Hospital were collected similarly and kept at -40 ° C until analyzed.
Measurement of plasma GMP-140. Plasma GMP-140 levels were measured with a GMP-140 kit (Takara Bio- medicals, Kyoto), as described previously. It' 1~ Two mono-
clonal antibodies, WGA-1 monoclonal antibody (immu- noglobulin Gx) produced in mice in response to proteins from 1% deoxycholate extract of human platelet mere-
274 Halim et al. January 1996 AmJ Obstet Gynecol
0
~E
1800
1500
1200
900
600
300
0
0
p < O. 0001 P = 0. 007 r 1
i i
p= 0.03
! p = O. 0004
,t !!
NS I I
Q
i p= 0'01 i •
ii,, 14
12
i '° 8
6
i, N
2
0
x Preecl ampsi a Normal pregnancies • Eclampsia
Fig. 1. Plasma concentration (mean _+ SD) of GMP-140 and platelet glycocalicin. The GMP-I40 and glycocalicin levels are significantly elevated in preeclampsia (x) (n= 10) and eclampsia (o) (n= 20) compared with normal pregnancies in third trimester (o) (n = 10). NS, Not significant.
b rane b o u n d to a wheat germ agglutinin and PLT-6 mono-
clonal ant ibody ( immunoglobul in G1) raised in response to freshly washed platelets, are used in this kit. The speci- ficity of these antibodies was demonstra ted previously. 17' ]a
The intraassay and interassay coefficients of variation were 7.5% to 17.5% and 7.6% to 17.4%, respectively.
Briefly, 96-well enzyme immunoassay plates were coated with WGA-1 monoc lona l ant ibody and then
blocked with 3% bovine serum albumin. A volume of 100 pl of ei ther plasma sample or s tandard GMP-140 (differ-
en t concentrat ion) was added to each well. The plates
were incubated for 1 hour at 37 ° C and washed with phosphate-buffered saline solution. T h e n 100 pl of per-
oxidase-conjugated PL7-6 monoc lona l ant ibody solution
was added to each well; this mixture was incubated for 1 hour at 37 ° C. After four washes with phosphate-buffered saline solution they were reacted with 100 pl of a solution of 5.5 m m o l / L o-phenylenediamine hydrochloride
(Sigma, St. Louis) for 15 minutes. The enzyme reaction was stopped by adding 1N sulfuric acid. Then the absor- bencies were measured by a photometer (Bio-Rad, Rich-
mond , Calif.) at 492 nm. GMP-140 levels were calculated from a standard curve plotted as directed in the kit.
Measurement o f p lasma glycocalicin. Plasma glycocali-
cin levels were measured with an enzyme4inked immu- noso rben t assay kit (Takara Biomedicals). Two mur ine monoclona l antibodies used in the kit, HPL-7 ( immuno- globulin G1) and HPL-16 ( immunoglobu l in G1) are spe- cifically reactive with h u m a n platelet m e m b r a n e glyco- protein Ib. The specificity of these antibodies was demon- strated previously. ~9 The intraassay and interassay coefficients of variation were 3.6% to 5.2% and 5.4% to 8.0%, respectively. 19
Briefly, 96-well enzyme immunoassay plates were
coated with HPL-16 monoc lona l ant ibody and then blocked with 3% bovine serum albumin. A volume of 100
lal of either plasma sample or s tandard glycocalicin (dif- ferent concentrat ions) was added to each well. The plates were incubated for 1 hour at 37 ° C and washed with
phosphate-buffered saline solution. T h e n 100 Ill of per- oxidase-conjugated HPL-7 monoc lona l ant ibody solution was pipet ted into each well; this mixture was incubated
for 1 hour at 37 ° C. After four washes with phosphate- buffered saline solution, they were reacted with 100 pl of
a solution of 5.5 m m o l / L o-phenylenediamine hydro-
chloride for 15 minutes. The enzyme reaction was
stopped by adding 1N sulfuric acid. T h e n the absorben- cies were measured by a photometer (Bio-Rad) at 492
nm. Glycocalicin levels were calculated from a standard curve plotted as directed in the kit.
Measurement o f the plasma thrombin-antithrombin complex . The concent ra t ion of th rombin-an t i th rombin complexes was measured in plasma with Enzgnost, an enzyme-linked im m unoso rben t assay kit (gehringwerke,
Marburg). Statistical analysis. We compared the plasma levels of
GMP-140 and glycocalicin among the groups by use of the
Mann-Whitney U test. The glycocalicin index was calcu- lated as m e n t i o n e d by Beer et al. 16 The glycocalicin in-
dex was glycocalicin normal ized for the individual plate- let count. Glycocalicin index = [Glycocalicin value (pg /ml) x (250 × 106 p la te le t s /ml ) ] / ( Ind iv idua l platelet count). Correlations between these values (GMP-140, gly- cocalicin, or glycocalicin index) and the systolic blood pressures, m e a n blood pressures (Diastolic blood pres- sure + 1/3 x [Systolic blood pressure - Diastolic blood
Volurne 174, Number 1, Part 1 Halim et al. 275 Am J Obstet Gynecol
,~ 1600
1200
8 0 0
=L 400
0 • 6O
a o r =-.42, p = 0.23
r = 0.58, p= 0.07
• r = 0.44, p = 0.05
" ,
80 100 120 140 160
b o r = 0.19, p= 0.59
I t r =-0 .71, p = 0.01
• r =-0 .58, p=O.OO5
"'4D • • •
• N ""
0 15 20 25 30 35 40 45
C o r = 0 . 3 1 , p = 0 . 3
Ill r = 0.94, p< 0.0001
• r = 0.56, p = 0.009
t • " " " |
_ • y
0 10 20 30 40 50 60 70
,u d o r = 0 . 3 , p = 0 . 3 9
X r =-0 .21, p = 0.5
• r =-0.5, p = 0.02
12 • o° •
10 • •
O / ,
6G 8o 100 120 140 160
Mean Blood Pressure (mmHg)
e o r = 0.23, p = 0.52
I t r =-0 .61, p = o.os
• r =-0 .47, p= 0.03
. . . . , . . . . . . . . . , . . t , . . . . . . . . . , . . . . I
0 I s eo 2s 30 3s 40 4s
Platelet counts(xlOT/ml)
f o r = O A , p = 0 . 7 6
Ig r =-0.73, p= 0.01
• r =-0.50, p = 0.02
I ° ."" , .xl~""
:
o 1o 2o 30 40 so 60 70
TAT complexes (ng/ml)
Fig. 2. Correlations between mean blood pressures and GMP-140 (a), platelet counts and GMP-140 (h), thrombin-antithrombin (TAT) complexes and GMP-140 (c), mean blood pressure and glycocalicin (d), platelet counts and glycocalicin (e), and thrombin-antithrombin complexes and glycocalicin (f). Signif- icant correlations between GMP-140 or glycocalicin levels and plasma thrombin-antithrombin complexes and platelet counts exist in preeclampsia (x) (n = 10) and eclampsia (.) (n = 20). In all cases pvalues are shown; p values were obtained with Fisher's r to z analysis compared with normal pregnancies (o) (n= 10). Solid regression lines ( ) represent eclamptic patients (°), whereas dotted lines ( . . . . ) are for preeclamptic patients (x).
Table II. Correlat ions between plasma concentrat ions of GMP-140 and glycocalicin
Normal pregnancies Preeclamptic patients Eclamptic patients All casees collectively
No. 10 10 20 30 Correlation coefficient -0.58 0.71 0.77 0.80 Significance NS p = 0.01 p < 0.0001 p < 0.000
NS, Not significant (p > 0.05).
pressure]), platelet counts, and plasma thrombin-ant i-
th rombin complex values in separate groups were ana-
lyzed. The p values were obta ined with Fisher 's r (correla-
tion coefficient) to z analysis.
R e s u l t s
The mean (+_SD) plasma GMP-140 levels in normal
pregnancies (n = 10) and preeclampt ic (n = 10) and ec-
lamptic patients ( n = 20) were found to be 174 + 67.6,
642 _+ 349, and 1031 _+ 474 n g / m l . The GMP-140 levels
were significantly h igher in preeclampt ic (p= 0.0004)
and eclamptic cases (p< 0.0001) compared with normal
pregnancies in the third trimester. Eclamptic patients
had a h igher value than did preeclampt ic patients
(p < 0.03). The glycocalicin levels in normal pregnancies
( n = 10) and preeclampt ic (n = 10) and eclamptic moth-
ers ( n = 20) were 3.53 + 0.87, 6.64 _+ 2.6, and 7.89 _+ 3.5
lag/ml, respectively. Glycocalicin levels were significantly
elevated in preeclampt ic (p= 0.01) and eclamptic cases
(p= 0.007) compared with normal pregnancies. How-
ever, no significant difference was observed between the
glycocalicin concentrat ions in the preeclamptic and
eclamptic groups. Fig. 1 shows the GMP-140 and gtyco-
calicin values in the plasma of all cases inc luded in this
study. The glycocalicin index values are also h igher in
eclamptic (9.0 + 0.8, p = 0.0008) and preeclampt ic cases
(6.9 _+ 3.6, p = 0.001) compared with normotens ive con-
trols (2.6 + 0.8).
A correlative analysis between plasma GMP-140 and
glycocalicin levels or glycocalicin index values and their
cor responding systolic b lood pressures, mean blood pres-
sures, platelet counts (xlOT/ml), or plasma thrombin-
276 Halim et al. January 1996 Am J Obstet Gynecol
antithrombin complex values in separate groups was per- formed. Fig. 2 shows the correlations between GMP-140 and mean blood pressures (a), GMP-140 and platelet counts (b), GMP-140 and thrombin-antithrombin com- plexes (c), glycocalicin and mean blood pressure (d), gly-
cocalicin and platelet counts (e), and glycocalicin and
thrombin-antithrombin complexes 09 in separate groups. The r and p values were also presented in the figure. No significant correlation among these parameters was ob-
tained in normal pregnancies (n = 10). Mean blood pres- sures in preeclamptic cases had no significant correlation
with their corresponding plasma GMP-140 and glyco-
calicin or glycocalicin index values, whereas in eclamptic
cases correlations between these parameters were found (r= 0.43 to 0.54, p < 0.05). The thrombin-antithrombin
complex levels had significant correlations between thrombin-antithrombin complexes, and plasma GMP- 140, glycocalicin, or glycocalicin index values were found
in preeclamptic (r--0.94, 0.73, 0.78) and eclamptic pa-
tients (r= 0.55, 0.5, 0.46). The platelet counts correlated negatively with the corresponding plasma GMP-140, gly-
cocalicin, or glycocalicin index values in preeclamptic (r=-0.71, -0.61, -0.86) and eclamptic patients
( r=-0 .58 , -0 .47 , -0.7, respectively). As shown in Table II, significant correlations were
found between plasma GMP-140 and glycocalicin levels
either in preeclamptic (r= 0.71), eclamptic (r= 0.77), or all (normal, preeclamptic, eclamptic) together (r= 0.8, n = 30). However, we did not find any significant correla-
tion between GMP-140 and glycocalicin in normotensive
controls (n = 10).
Comment
We are the first to report an elevation of plasma GMP- 140 and platelet glycocalicin concentrations in preec-
lamptic and eclamptic patients. Compared with those of
normotensive controls, plasma GMP-140 and glycocalicin
levels in preclamptic and eclamptic patients were mark- edly elevated. However, this increase was more pro- nounced in eclamptic than in preeclamptic cases. On platelet or endothelial activation, GMP-140 is rapidly re- distributed on the surface from the internal stores 12' 13
and released into the circuIation by proteolysis or vesicu- lation. 2° Because messenger ribonucleic acid encoding
the soluble form of GMP-140 exists in both endothelium and platelets, ~1 plasma GMP-140 can be derived from either or both of these sources. Soluble forms of surface
membrane glycoprotein in various cells have been iden- tified as markers for in vivo cellular activity, lz' 14 Therefore the elevated plasma concentration of GMP-140 is a novel finding in preeclampsia and eclampsia and essentially supports the concept of platelet and endothelial cell ac- tivation in this disease. As such, GMP-140joins the grow- ing list of markers of endothelial dysfunction and platelet hyperactivity described in this disorder.
We also found an elevation of plasma glycocalicin levels and corresponding glycocalicin index values in preec-
lamptic and eclamptic patients compared with normoten- sire controls. These values correlated negatively with platelet counts. The plasma glycocalicin concentration is
also dependen t on the platelet mass. The glycocalicin index was described to reflect platelet turnover or plate- let dysfunction) < 22 Therefore the elevation of the plasma
glycocalicin level and glycocalicin index in our study defi- nitely reflect the platelet activation and its consequences
in this disease. The elevation in plasma concentration of GMP-140 was more (significantly) pronounced in ec-
lamptic cases (most severe form of this disease) com-
pared with preeclamptic patients. The plasma glycocali-
cin levels in preeclamptic patients did not significnatly differ from those in the eclamptic group. An elevated
plasma glycocalicin level was described to be a result of the proteolytic cleavage of the surface-expressed glyco- protein Ib in activated platelets in vivo. 16' 22 Therefore we
suggest that the elevated plasma glycocalicin concentra-
tion in this study might reflect the proteolytic cleavage of surface-expressed glycoprotein Ib in activated platelets.
Blood pressures (as clinical parameter), platelet counts
(for platelet activation and consumption), and thrombin- antithrombin complexes (for hypercoagulability and
thrombin generation) are important parameters to re-
flect the status of this diseaseT', Significant correlations
between the platelet counts or thrombin-antithrombin complex values and their corresponding plasma GMP- 140 and glycocalicin concentrations exist in both preec- lamptic and eclamptic cases. The correlations are found to be more significant in eclamptic than in preeclamptic
patients. Blood pressure did not correlate significantly with GMP-140, glycocalicin, or glycocalicin index values
in preeclamptic cases. However, in eclamptic patients we
found significant correlations between these parameters. Mthough the statistical correlation does not essentially
reflect the events in vivo, however, we suggest that the
plasma GMP-140 and glycocalicin concentrations might increase parallel to the progression of the disease.
The platelet activation and endothelial dysfunction
in preeclampsia-eclampsia were suggested previously. ~ There could be multiple triggers for cellular activation in
this disease. However, generalized vasospasm caused by imbalance between vasoconstrictors and vasodilators and increased complements and thrombin generation could be the important causes for cellular activation. Current evidence suggests that GMP-140 plays a fundamental role
in both limiting and mediating the interaction of neu- trophils with endothelial cells and others. 1°' 23 Neutrophil activation was also reported in preeclampsia. 4 GMP-140
mediates the binding of leukocytes to activated vascular 10 endothelium and plays a role in cellular interactions. '
1J Wong et al. 24 found an inhibitory effect of GMP-140 on superoxide release by human neutrophils. On the other hand, glycocalicin is not only a marker of platelet acti- vation but also indicates the loss of one receptor for yon Willebrand factor and thrombin on platelet surface) < 25 In addition, glycocalicin was reported to function as a
Volmne 174, Number 1, Part 1 Halim et al. 277 :~ml j Obstet GynecoI
circulating inhibi tor of thrombin. ~5 In this study we could
not identify the funct ions of these two circulat ing mol-
ecules. However, we suspect that a homeostat ic funct ion
of the circulat ing GMP-140 and glycocalicin might exist
in this disease. This topic should be investigated fur ther
in detail.
De te rmina t ion of surface-expressed GMP-140 is
known to represent platelet or endothel ia l cell activation.
However, the plasma level of GMP-140 may provide a
useful marker of e i ther platelet activation or vascular
endothel ia l dysfunction in such diseases. Moreover, an
enzyme-l inked i m m u n o s o r b e n t assay kit for measur ing
plasma GMP-140 or glycocalicin may provide an extra
advantage for clinical use.
We thank Dr, Faruque A. Azim, Depa r tmen t of Pathol- ogy, Dacca Medical College, Bangladesh; Dr. Azad Khan and Dr. Liaquat All of Birdem, Bangladesh, for technical advice and for providing us u~th the facilities for preser- vation of the samples at <-40 ° C until transfer to Japan.
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