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Objective: To investigate the abnormal abundances of calcium regulatory proteins in rabbit myocytes with failing hearts., Methods: Sixteen rabbits were divided into two groups: 8 rabbits with heart failure induced by volume plus pressure overload and 8 sham-operated animals. The hemodynamic parameters and cardiac structure and function were detected via catheterization and echocardiography respectively. L-type calcium channel (LTCC), Ryanodine receptor 2 (RyR2), Sarcoplasmic reticulum Ca(2+)-ATPase (SERCA2a), and Na(+)-Ca(2+) exchanger (NCX) protein abundances were determined by Western blot analysis., Results: The ratio of left ventricular mass to body weight, heart rate and left ventricular end diastolic pressure in heart failure rabbits were significantly increased compared with sham-operated rabbits (P < 0.01), but their left ventricular shorten fraction [(21.3 +/- 4.00)% vs. (36.5 +/- 1.36)%] and ejection fraction (0.45 +/- 0.07 vs. 0.70 +/- 0.02) were decreased (P < 0.01). In heart failure rabbits, the abundances of LTCC and RyR2 were significantly decreased (R(LTCC/actin): 0.287 +/- 0.029 vs. 0.624 +/- 0.009; R(RyR2/actin): 0.106 +/- 0.001 vs. 0.203 +/- 0.011; P < 0.01), whereas the expressions of SERCA2a and NCX were markedly increased (R(NCX/actin): 0.497 +/- 0.015 vs. 0.221 +/- 0.014; R(SERCA2a/actin): 0.611 +/- 0.036 vs. 0.433 +/- 0.008; P < 0.01)., Conclusions: Reductions of LTCC and RyR2 might contribute to risk factors of systolic dysfunction in failing hearts. In early stage of heart failure, upregulated SERCA2a and NCX protein levels may be helpful for maintaining cardiac performance.

Objective: To establish a high-performance liquid chromatography with visible wavelength detection method for rhodamine 123 in cell lysate., Methods: The HPLC separation was performed on a Kromasil C(18) (5 microm, 4.6 mm x 250 mm) column, using water (15 mmol/L potassium acetate and 1.2 mmol/L tetrabutylammonium bromide) - acetonitrile (65:35) as the mobile phase. The wave length was 390 nm, the internal standard was rhodamine B. Protein in the sample was precipitated by trichloroacetic acid., Results: The calibration curve was linear in the range of 3 - 300 microg/L. The intra-day and inter-day RSDs were less than 5%., Conclusion: The method is accurate,sensitive, simple, and reliable for determining rhodamine 123 in cell lysate.

The name of chest bi was originated from Neijing (Internal Canon), with its discussion related to the lung. The concept of chest bi was broadened and varied in the latter works of traditional Chinese Medicine in later generations. Nowadays, the textbook of Internal Medicine of Chinese Medicine, the state and the professional standards define thechest bi to coronary heart disease, thus reducing the scope of chest bi.

Background: Atrial fibrillation is the most common cardiac rhythm disturbance in clinical practice; its risk factors are complex and far from being clarified up to now. Previous studies demonstrated that hypoalbuminaemia significantly correlates with cardiac diseases., Hypothesis: We hypothesized that the serum albumin levels were decreased in patients with paroxysmal atrial fibrillation (PAF) and that hypoalbuminaemia was a risk factor for PAF., Methods: We selected retrospectively 32 consecutive PAF patients as experimental group and 32 strictly age- and sex-matched paroxysmal supraventricular tachycardia patients confirmed by electrophysiology as a normal control group. Serum albumin was assayed by the bromocresol green (BCG) method. The experimental group was compared with the control group using the paired sample t test for independent samples when dealing with approximately normally distributed variables and the Wilcoxon rank-sum test when appropriate. One sample t test was used to compare albumin levels of the control group with the normal population mean value established in this laboratory so as to eliminate the selection bias. The correlations between albumin levels and cardiac function classifications (NYHA) were assessed using Spearman's rho. Categorical variables were compared using chi-squared, Fisher's exact test or RxC contingency table. Logistic regression was used for analysis of risk factors of serum albumin levels and PAF., Results: The baseline clinical characteristics between the 2 groups were comparable with no significant difference. In a univiariate analysis, albumin was significantly lower in patients with PAF (41.67 +/- 3.52 g/L) than in control patients (43.88 +/- 3.53 g/L, P = 0.009). The albumin levels among patients in the presence and the absence of baseline factors showed insignificant difference (P > 0.05). In a multivariable analysis of covariance that considered baseline factors, only PAF was an independent predictor of decreased albumin levels (P = 0.0454, OR = 0.375). Conversely, only hypoalbuminaemia was an independent predictor of PAF (P = 0.0129, OR = 0.773)., Conclusions: PAF is associated with hypoalbuminaemia and hypoalbuminaemia is an independent risk factor for PAF patients. Although the cause and effect of hypoalbuminaemia and PAF remains to be clarified, the present study provides new information with respect to the aetiology and therapy of PAF patients.

Objective: Hypertrophic cardiomyopathy (HCM) is a genetically and phenotypically heterogeneous disease and an Arg723Gly mutation in beta-myosin heavy chain (beta-MHC) gene was found in 3 Spanish families with malignant HCM. We detected this gene mutation in 5 Chinese pedigrees with hypertensive cardiomyopathy., Methods: Five Chinese pedigrees with HCM and 80 age-matched normal control subjects were chosen for the study. The exons in the functional regions of the beta-MHC gene were amplified with PCR and the products were sequenced, genotype and phenotype analyzed., Results: Arg723Gly mutation was identified in exon 20 in one pedigree. In this pedigree, 13 out of 25 family members were diagnosed as HCM, 5 died of heart failure, all HCM patients in this pedigree had Arg723Gly mutation and 3 of them had NYHA III and 2 of them were diagnosed as HCM before the age of 20., Conclusions: Arg723Gly mutation was also one of the main disease-causing genes in Chinese familial HCM. The mutation of Arg723Gly is a malignant phenotype as shown by early progressive heart failure development and poor prognosis in this pedigree with Arg723Gly mutation.

Background: Thallium-201 (201Tl) myocardial perfusion imaging has been widely used for evaluation of myocardial ischemia/viability after myocardial infarction. The 3- to 4-h early redistribution imaging has underestimated a considerable part of viable myocardium, while the 24-h late redistribution imaging may enhance the detection of myocardial ischemia/viability, but remains controversial., Methods: Thirty-eighty patients with myocardial infarction underwent the initial, 3-h, and 24-h redistribution imaging after intravenous injection of 148-185 MBq 201Tl. Image quality analysis was performed using a four-grade model: excellent, good, moderate, and poor. The initial and 3-h images, the initial and 24-h images, and the 3- and 24-h images were compared double-blinded., Results: The 3- and 24-h images showed no significant differences in image quality according to the four-grade model (P=.3580). Out of the 194 abnormal segments based on the initial imaging, 60 (31%) segments improved by at least one grade on the 3-h imaging, while 86 (44%) segments improved by at least one grade on the 24-h imaging. The 24-h late imaging detected more viable myocardium than the 3-h imaging did, with a significant difference (chi2=7.4235, P=.0064). There were 164 abnormal segments on the 3-h imaging, with an average 30% (48) segments improved by at least one grade on the 24-h imaging. There were 134 initial abnormal segments without any improvement on the 3-h imaging. Out of these segments, the 24-h late redistribution imaging detected additional redistribution in 30 segments, taking up 22%. The mean global score on the 3-h imaging significantly decreased compared to that on the initial imaging (t=5.71, P<.0001), and the mean global score on the 24-h imaging further decreased significantly compared to that on the 3-h imaging (t=6.28, P<.0001)., Conclusions: Twenty-four-hour late 201Tl imaging, with satisfactory image quality, enhances the detection of myocardial viability after myocardial infarction.

Background: Rest thallium-201 (201Tl) myocardial perfusion imaging has been widely used for evaluation of myocardial ischemia/viability after myocardial infarction, but the ideal timing for imaging after injection to maximally estimate viability is not well established., Methods: Thirty-six patients with myocardial infarction underwent the initial, 3 h, and 24 h redistribution imaging after intravenous injection of 148-185 MBq 201Tl. The initial and 3 h images, the initial and 24 h images, and the 3 and 24 h images were compared double-blinded., Results: Out of the 184 abnormal segments based on the initial imaging, 56 (30%) segments improved by at least 1 grade on the 3 h imaging while 78 (42%) segments improved by at least 1 grade on the 24 h imaging. The 24 h late imaging detected more viable myocardium than the 3 h imaging did, with a significant difference (chi2= 5.680, p = 0.017). There were 158 abnormal segments on the 3 h imaging, with average 28% (44) segments improved by at least 1 grade on the 24 h imaging. There were 128 initial abnormal segments with no improvement on the 3 h imaging. Out of these segments, the 24 h late redistribution imaging detected additional redistribution in 26 segments, taking up 20%., Conclusions: Twenty-four hour late 201Tl imaging will demonstrated additional redistribution in patients who have incompletely reversible defects on early redistribution imaging at 3h.

Until recently, the characterization of adenosine A(2B) receptors has been hampered by the lack of high affinity radioligands. This study describes the synthesis and in vitro characterization of the radiolabeled derivative of OSIP339391, a novel, potent, and selective pyrrolopyrimidine A(2B) antagonist. OSIP339391 had a selectivity of greater than 70-fold for A(2B) receptors over other human adenosine receptor subtypes. The radiolabel was introduced by hydrogenation of the acetylenic precursor with tritium gas resulting in the incorporation (on average) of three tritium atoms in the molecule, yielding a ligand with specific activity of 87Ci/mmol (3.2TBq/mmol). Using membranes from HEK-293 cells expressing the human recombinant A(2B) receptor, [3H]OSIP339391 was characterized in kinetic, saturation, and competition binding experiments. From the association and dissociation rate studies, the affinity was 0.41nM and in close agreement with that found in saturation binding experiments (0.17nM). In competition, binding studies using 0.5nM [3H]OSIP339391, the affinity of a range of agonists and antagonists was consistent with previously reported data. Thus, [3H]OSIP339391 is a novel, selective, and high affinity radioligand that can be a useful tool in the further exploration and characterization of recombinant and endogenous adenosine A(2B) receptors.

Objective: To study the mechanism of the effects of microwave on learning and memory., Method: Long-term potentiation (LTP) of hippocampus induced potential and lipofuscin content in rat brain were studied. After irradiated by a 2450 MHz microwave, rats hippocampus induced potential in vivo was recorded and lipofuscin content in the brain was measured by fluorospectrophotometry., Result: Continuous microwave with 10-25 mW/cm2 intensity could inhibit the amplitude of the population spike (PS) of weak and strong stimuli induced LTP with an intensity-effect relationship. At 25 mW/cm2, lipofuscin content was significantly higher than control and 10 mW/cm2 group (P<0.05)., Conclusion: Continuous microwave with 10-25 mW/cm2 intensity impairs learning and memory by restraining hippocampus LTP and brain lipofuscin content.

Background: Chromosomal numerical abnormality (CNA) is a characteristic of breast cancer as with other common solid cancers. Multiple mammary carcinomas are also sometimes encountered in the ipsilateral breast. Deciding whether they are multicentric (arising independently) or multifocal (of the same origin) has been a continued challenge to clinicians and pathologists., Methods: We experienced two cases of macroscopically distinct double carcinomas in the ipsilateral breast, in which two cancers had a different histopathological morphology. Centromere probes identifying 17 different and specific centromeres were used to obtain the profile of CNA for each tumor, with a microwave-assisted FISH protocol. For comparison, a case of three lesions, two of which had the same and the other different histology was also studied., Results: Contrary to our expectations, in spite of the particular difference in the histopathological picture of these tumors, the CNA profile was the same in one case and different in the other. The gain of chromosome 1 and loss of chromosome 15 are representative features shared by multifocal cases. On the other hand, the multiple cancers with the same histology had mostly the same CNA profile., Conclusions: CNA profiling is useful to identify the lineage of multiple breast cancers. As shown here, regardless of the histological features, a certain common CNA profile can define the same origin of some multiple cancers.

Objective: To evaluate the changes of plasma levels of brain natriuretic peptides in patient with chronic heart failure (CHF) and the effect of beta-blockers (BB) on CHF., Methods: We enrolled 33 patients with CHF, NYHAII-III, age 19 - 76 (57.5 +/- 15.8) years. Plasma levels of atrial and brain natriuretic peptides (ANP, BNP) were measured with radioimmunoassay and immunoradiometric assay in these patients. All the patients were assigned to 3 groups as follows: standard therapy group 12 cases (receiving ACEI + digoxin + diuretic), metoprolol treatment group 10 cases (receiving metoprolol in addition to the standard therapy), carvedilol treatment group 11 cases (receiving carvedilol in additional to the standard therapy). These patients were treated for three months, the therapeutic effects were assessed by change of plasma levels of ANP and BNP., Results: Plasma levels of ANP and BNP were significantly elevated in CHF patients. After treatment, ANP and BNP plasma levels both decreased significantly. In patients receiving beta-blockers, BNP plasma levels decreased most significantly., Conclusion: BNP plasma level is a good marker to reflect left ventricular function. Measurement of BNP plasma level is useful to monitor the change of left ventricular function and to evaluate the effect of treatment with beta-blockers.

Objective: To study the effect of microwave irradiation on hippocampus cell., Method: Changes of ATPase activity and voltage dependent ion channel of hippocampus cell membrane were observed in mice exposed to 2 450 MHz microwave irradiation of 10 mW/cm2 from a physical therapy machine. Histochemical method and patch clamp method were used to determine the activity of Na+, K(+)-ATPase, Ca2+, Mg(2+)-ATPase and voltage dependent Na+, K+, Ca2+ channels respectively., Result: 1) Na+, K(+)-ATPase activity of microwave irradiated mice showed no significant change as compared with the control, but the activity of Ca2+, Mg(2+)-ATPase decreased significantly (P< 0.05); 2) In microwave irradiated mice, Na+, K+, Ca2+, current inducement rate in hippocampus neuron decreased significantly, the membrane voltage of Na+ current peak shifted to depolarization, and the attenuation rate of Na+ current and current A inducement rate decreased significantly as compared with control mice., Conclusion: Irradiation of 2 450 MHz microwave at a doze of 10 mW/cm2 was not fatal to mice hippocampus cell. But Ca2+, Mg(2+)-ATPase activity of hippocampal cell membrane and voltage dependent Na+, K+, Ca2+ ion channel of hippocampal nervous were affected which would affect study and memory.

Background: Germline mutation in the cell adhesion molecule E-cadherin is known to be associated with the development of undifferentiated or diffuse-type familial gastric cancers, but the prevalence of this contribution seems to be low in Japanese familial cases, so far., Methods: We screened all exons of the E-cadherin gene for mutations in 101 Japanese patients having an intense family history of gastric cancers., Results: An abnormal band pattern was found in exon 9 in three patients (Y6, B21, B37) from two families by PCR-SSCP. DNA sequencing analysis of these three patients revealed isoleucine-leucine substitution at codon 415 in exon 9. B21 and B37 are siblings and the other three brothers died of gastric cancer and another brother (B36) has not been affected by gastric cancer to date. This case (B36) did not have this alteration in the exon 9 of E-cadherin., Conclusion: Although the mechanistic basis is not clear, our findings may provide a possibility that this additional missense mutation in germline E-cadherin gene may contribute to gastric cancer predisposition.

Objective: To study the changes of expression and secretion of some growth factors and ERK1/2 activation in cardiac fibroblasts under clinorotation conditions., Method: Primary cultured neonatal rat cardiac fibroblasts were clinorotated to simulate weightlessness. The bFGF and TGF(beta)1 expressions in the cells and Ang II concentration in the medium were detected by western blotting and radioimmunoassay respectively. The expression and phosphorylated level of ERK1/2 were analyzed by western blotting., Result: Compared to the control group, bFGF expression and Ang II concentration increased in clinorotation group, but there was no evident change in TGF(beta)1 expression. At the same time, the expression of ERK1/2 increased but their phosphorylated level decreased., Conclusion: Different growth factors responds to clinorotation by different ways. As one of the most important reactions of growth factor signal downstream pathways, ERK1/2 activation is inhibited in clinorotation.

Papillary adenocarcinoma of the stomach is a relatively uncommon histological type, and it is often detected in the early stage. We recently characterized the papillary type of gastric cancer and found frequent microsatellite instability and associated mutations. In this study we analyzed the centromere numerical abnormality (CNA) of 18 chromosomes (chromosomes 1-4, 6-12, 15-18, 20, X, and Y) in the papillary and papillotubular types of gastric cancer by a modified fluorescence in situ hybridization technique with microwave treatment. All 3 cases (100%) of papillary adenocarcinoma had high microsatellite instability (MSI-H), and low CNA, and 41% (7 cases) of the 17 cases of papillotubular adenocarcinoma exhibited MSI-H and all 7 cases had low CNA. Further 8 cases (47%) had extensive CNA. In these 15 cases, all the MSI-H cases had lower CNA, and low microsatellite instability (MSI-L) and MSS cases had higher CNA. The remaining two cases showed low CNA and MSI-L and MSS. These profiles were different from those of tubular type gastric cancer, which always had extensive CNA and no MSI. Although the numbers of the cases in this series are limited, our data may suggest that a modest CNA may be another characteristic of gastric cancer with papillary structure.

Purpose: We have previously reported that EPHB2 is overexpressed in gastric cancer; however, the expression profiles of its ligands, EFNB1 and EFNB2, are unknown. This study was designed to investigate the expression of EPHB2 and its ligands, EFNB1 and EFNB2, in human gastric cancer., Methods: Semi-quantitative RT-PCR using (32)P was performed on human gastric cancer tissues and corresponding normal tissues (29 gastric cancer patients)., Results: EPHB2 was more highly expressed in tumor tissues than in normal tissues in 21 out of 29 (72.4%), in gastric cancer patients ( P = 0.01); EFNB1 and EFNB2 were highly expressed in 21 out of 29 (72.4%) ( P = 0.037) and 14 out of 29 (48.3%) patients, respectively. The overexpression of EPHB2 was frequently detected in both well-differentiated adenocarcinoma and poorly differentiated adenocarcinoma [10/13 (76.9%) and 9/14 (64.3%), respectively]. On the other hand, the overexpression of EFNB1 was more frequently detected in poorly differentiated adenocarcinoma than in well-differentiated adenocarcinoma [12/14 (85.7%) and 7/13 (53.8%), respectively. P =0.027]. Elevated levels of EPHB2 and EFNB1 were detected in substantial subsets of early gastric cancers. Genomic alterations to these three genes in gastric cancer specimens were either not found or rarely found except for several rare variations of EPHB2., Conclusions: These findings suggest that not only the expression of EPHB2, but the expression of its ligand EFNB1 may have some relation with the oncogenesis of gastric cancer.

beta-PIX, a newly identified p21-activated kinase (PAK)-interacting exchange factors (PIX), encodes a guanine nucleotide exchange factor for Rho guanosine triphosphatases. Characterization of beta-PIX gene was performed using the BAC Library method. The beta-PIX gene has 17 exons and an A/T polymorphism at the 32nd base upstream of the intron/exon junction of exon 7. The frequencies of genotypes A/T, A/A and T/T were 23.6% (13/55), 72.7% (40/55) and 3.6% (2/55), respectively; these frequencies are in Hardy-Weinberg equilibrium. Two out of 14 informative tumors (14.3%) were shown to have lost their heterozygosity at this locus, but no mutations in the remaining alleles were detected. In addition, we examined the gene-expression profile in another set of 30 gastric samples, but no significant over-expression of either the beta-PIX gene or the alpha-PIX gene was found. Though the beta-PIX gene has been speculated to potentially have tumor-related biological characteristics, the findings of the present study suggest that the involvement of beta-PIX gene in human gastric carcinogenesis is minimal.

Objective: To investigate the effect of simulated weightlessness on apoptosis of thymus cells in mice., Method: Tail-suspended mice were used as an animal model of simulated weightlessness; chromosome breakage was measured by PI staining, and changes of cell membrane were determined by Annexin-V analysis., Result: As compared with the control, there was no obvious chromosome breakage; the total number of apoptotic cells and number of early apoptotic cells increased in 1 d suspended group; the number of early apoptotic cells increased significantly and the total number of apoptotic cells increased very significantly in 2d suspended groups., Conclusion: These results suggested that simulated weightlessness could promote apoptosis of thymus cells.

Objective. To observe the protective effects of two kinds of Chinese herb-compounds (Dan-huang-ci compound and Shen-chuan-shu compound) on cellular immunology in tail-suspended rats. Method. The rats were divided into: 1) normal control group; 2) tail-suspended group; 3) tail-suspended + Dan-huang-ci compound; and 4) tail-suspended + Shen-chuan-shu compound. Ability of lymphocyte proliferation and production of IL-2 in rats in the four groups were compared after 21 d. Result. The immunological function of tail-suspended control group decreased significantly as compared with normal control group. Shen-chuan-shu compound could improve immunological function of tail-suspended rats obviously. Conclusion. Shen-chuan-shu compound could enhance cellular immunological function in rats under simulated weightlessness.

EphB2, a member of the Eph receptor protein-tyrosine kinase family, is overexpressed in several human gastrointestinal tumors. Furthermore, the EphB2 gene is localized at 1p35-p36.1, a frequently deleted region in colon and other cancers. So, despite its overexpression in some kind of tumors, we decided to study the possibility of involvement in the EphB2 gene (EPHB2) mutation in colon cancers, because some of the well known tumor suppressor genes (e.g. p53) is overexpressed (really accumulated) in tumors. Fifty colon tumor samples of matched with their respective normal tissues, were studied for mutation of the EPHB2. Analysis of the genomic structure of EphB2 and survey of all 16 exons revealed an infrequent polymorphism (intron 2) and mutation (intron 8). Another polymorphism in exon 6, localized at nucleotide 1359 (A-->G) was found to be rather frequent in Japanese and Chinese subjects, but very rare in Caucasians. Taking advantage of this polymorphism within EPHB2, we surveyed the loss of heterozygosity (LOH) status of this gene in Japanese colorectal tumors. Among the 50 samples analyzed, 24 were informative, and LOH was found in five of the15 (33.3%) informative rectal cancer cases. Mutation analysis covering all 16 exons in the remaining allele did not reveal any mutations. Thus, EPHB2 is not a classical tumor suppressor gene.

PAK-interacting exchange factor (PIX) has been reported to mediate the recruitment of PAK into focal adhesions and activate Rac, thus creating a feedback loop that stimulate PAK and other targets. This pathway is thought to be related to cellular changes, such as transformation and migration, that are often encountered in cancer cells. Here, we report the genomic structure of alpha-PIX, one of the PAK- interacting exchange factors, including the identification of the promoter region, which consisted 772 amino acids in 22 exons, spanning about 100 kb on genome of X chromosome. All splice sites conformed to the GT-AT rule. To investigate the role of alpha-PIX in carcinogenesis, we screened 60 cases of gastric cancer for mutations and polymorphisms using an intron-primer that covered all the exons, but no mutations or polymorphisms were found in the coding region. However an 18 bp repeat of thymidine tract was present in 50 bp downstream from exon 12 and the deletion of variable numbers of mononucleotide repeats was observed in seven out of the 60 gastric cancer tissue specimens that were examined. These seven cases all exhibited a mutator phenotype, suggesting that the deletions are passenger mutations. Thus our results revealed that alpha-PIX probably does not play any primary role in human gastric carcinogenesis.

Objective. To observe bone mass changes during convalescence after simulated weightlessness. Method. 7-week-old rats were tail-suspended for 21 d then reloaded for 7 d and 21 d to recover, and measured serum BGP. Result. Tail suspension of rats for 21 d caused significant decrease of serum BGP and phosphorus as well as femur minerals. Serum BGP and femur minerals were still lower than control levels, but serum contents of calcium, phosphorus and magnesium increased significantly after reloading for 7 d. Femur minerals and serum BGP, calcium, phosphorus and magnesium returned to control levels after reloading for 21 d. Conclusion. The deficit in femur mineral induced by hindlimb unloading in rats can be restored by return to normal weight bearing, BGP can be used to monitor the case of its recovery.

The interaction of human immunodeficiency virus (HIV)-derived vectors with wild-type virus was analyzed in transduced cells. Vector transcripts upregulated by infection had no measurable effect on HIV type 1 (HIV-1) expression but competed efficiently for encapsidation, inhibiting the infectivity and spread of HIV-1 in culture and leading to mobilization and recombination of the vector. These effects were abrogated with a self-inactivating vector.

Both coronary arteriography (CAG) and myocardial emission computed tomography (ECT) were performed in 58 patients. According to CAG findings and clinical manifestations, 47 patients were diagnosed as coronary heart disease (CHD), while 11 not. CAG was abnormal in 39 patients of the 47. The sensitivity and specificity of CAG were 83% and 100% respectively. The diagnosis of CHD was made without any doubt in patients with abnormal CAG. The sensitivity of ECT was 97.9%, the specificity only 45.5%, and the predictive value of negative ECT 83.3%. Therefore, abnormal ECT should be closely related to the clinical manifestations in order to evaluate its significance and a normal ECT may rule out CHD with more reliability.

The human neutrophil lysosomal enzyme, myeloperoxidase (MPO), exists in three major and chromatographically distinct forms, MPO I, MPO II, and MPO III. We used cation-exchange medium-pressure liquid chromatography and kinetic microenzyme assay (or spectrophotometric monitoring) to analyze the secretion of MPO isoforms by neutrophils exposed to N-formylmethionylleucylphenylalanine (FMLP), digitonin, the ionophore A23187, and serum-opsonized zymosan A (SOZ). All three MPO isomers were released into the fluid phase after neutrophils were exposed to these secretagogues. A significant proportional increase in MPO I was released when neutrophils were stimulated with SOZ. MPO I was released in higher proportions than found in the whole cell constituency when neutrophils were stimulated with FMLP + cytochalasin B, A23187, and digitonin, but this was not statistically significant.

The effect of ouabain on the rabbit ear artery response to serotonin was assessed in isolated vascular rings mounted in tissue baths for the measurement of isometric contractions and denervated with 6-hydroxydopamine in vitro. Ouabain, 1 and 10 microM, caused 5- and 6-fold shifts to the left of the serotonin concentration-response curve (CRC). However, 10 microM ouabain caused only a 1.6-fold shift to the left of the norepinephrine CRC. In the absence of ouabain, 0.01 microM ketanserin had little effect, whereas 0.1 microM prazosin caused a marked shift to the right of the serotonin CRC. In the presence of ouabain, prazosin exhibited little or no antagonism below 3 microM serotonin. Antagonism by ketanserin was increased by 1 and 10 microM ouabain, yielding 6.5- and 10.5-fold shifts to the right of the serotonin CRC, respectively. Benextramine pretreatment to inactivate alpha adrenoceptors nearly abolished the rabbit ear artery response to serotonin. However, in the presence of 10 microM ouabain, there was a substantial recovery of the response to serotonin, and this response was antagonized by ketanserin. These results are consistent with our hypothesis that serotonergic receptors are present in the smooth muscle cell membranes of the rabbit ear artery but are either uncoupled to the contractile mechanism or in a low efficacy state. In the presence of ouabain, these receptors either become coupled or convert to a high efficacy state and thereby contribute to the serotonin-induced contraction. Because the serotonin CRC was shifted to the left in the presence of ouabain, it is likely that most of the CRC was below the threshold concentration at which serotonin activates alpha adrenoceptors. Thus antagonism by prazosin was lost.