DNA vaccines encoding interleukin-8 and RANTES enhance antigen-specific Th1-type CD4(+) T-cell-mediated protective immunity against herpes simplex virus type 2 in vivo

Chemokines are inflammatory molecules that act primarily as chemoattractants and as activators of leukocytes. Their role in antigen-specific immune responses is of importance, but their role in disease protection is unknown. Recently it has been suggested that chemokines modulate immunity along more classical Th1 and Th2 phenotypes. However, no data currently exist in an infectious challenge model system. We analyzed the modulatory effects of selected chemokines (interleukin-8 [IL-8], gamma interferon-inducible protein 10 [IP-10], RANTES, monocyte chemotactic protein 1 [MCP-1], and macrophage inflammatory protein 1 alpha [MIP-1 alpha]) on immune phenotype and protection against lethal challenge with herpes simplex virus type 2 (HSV-2). We observed that coinjection with IL-8 and RANTES plasmid DNAs dramatically enhanced antigen-specific Th1 type cellular immune responses and protection from lethal HSV-2 challenge. This enhanced protection appears to be mediated by CD4(+) T cells, as determined by in vitro and in vivo T-cell subset deletion. Thus, IL-8 and RANTES cDNAs used as DNA vaccine adjuvants drive antigen-specific Th1 type CD4(+) T-cell responses, which result in reduced HSV-2-derived morbidity, as well as reduced mortality. However, coinjection with DNAs expressing MCP-1, IP-10, and MIP-1 alpha increased mortality in the challenged mice. Chemokine DNA coinjection also modulated its own production as well as the production of cytokines. These studies demonstrate that chemokines can dominate and drive immune responses with defined phenotypes, playing an important role in the generation of protective antigen-specific immunity.

Isolation and characterization of tetracycline-resistant clinical isolates of Helicobacter pylori

Tetracycline is an important component of combination therapies for Helicobacter pylori eradication. Twenty-nine tetracycline-resistant isolates requiring MICs ranging from 4 to 16 microgram/ml were isolated from Korean (22 of 460) and Japanese (7 of 105) patients. Interestingly, all of the 29 tetracycline-resistant isolates exhibited cross-resistance to metronidazole, and the cross-resistance was transferred to tetracycline-sensitive H. pylori strains.

Randomized comparison of coronary stenting with optimal balloon angioplasty for treatment of lesions in small coronary arteries

AIMS

Angioplasty of lesions in small coronary arteries remains a significant problem because of the increased risk of restenosis. The aim of this study was to compare the efficacy of elective coronary stent placement and optimal balloon angioplasty in small vessel disease.

METHODS

One hundred and twenty patients with lesions in small coronary arteries (de novo, non-ostial lesion and reference diameter <3 mm) were randomly assigned to either balloon angioplasty or elective stent placement (7-cell NIR stent). The primary end-point was restenosis at 6 months follow-up. Optimal balloon angioplasty was defined as diameter stenosis less than or = 30% and the absence of major dissection after the angioplasty, and crossover to stenting was allowed.

RESULTS

Baseline clinical and angiographic characteristics were similar in the two groups. Procedure was successful in all patients, and in-hospital events did not occur in any patient. However, 12 patients in the angioplasty group were stented because of suboptimal results or major dissection. Postprocedural lumen diameter was significantly larger in the stent group than in the angioplasty group (2.44 +/- 0.36 mm vs 2.14 +/- 0.36, P<0.05, respectively), but late loss was greater in the stent group (1.12 +/- 0.67 mm vs 0.63 +/- 0.48, P<0.01, respectively). The angiographic restenosis rate was 30.9% in the angioplasty group, and 35.7% in the stent group (P = ns). Clinical follow-up was available in all patients (15.9 +/- 5.7 months) and clinical events during the follow-up were similar in both groups.

CONCLUSIONS

These results suggest that optimal balloon angioplasty with provisional stenting may be a reasonable approach for treatment of lesions in small coronary arteries.

Regulation of the rulAB mutagenic DNA repair operon of Pseudomonas syringae by UV-B (290 to 320 nanometers) radiation and analysis of rulAB-mediated mutability in vitro and in planta

The effects of the rulAB operon of Pseudomonas syringae on mutagenic DNA repair and the transcriptional regulation of rulAB following irradiation with UV-B wavelengths were determined. For a rulB::Km insertional mutant constructed in P. syringae pv. syringae B86-17, sensitivity to UV-B irradiation increased and UV mutability decreased by 12- to 14-fold. rulAB-induced UV mutability was also tracked in phyllosphere populations of B86-17 for up to 5 days following plant inoculation. UV mutability to rifampin resistance (Rif(r)) was detected at all sampling points at levels which were significantly greater than in nonirradiated controls. In P. aeruginosa PAO1, the cloned rulAB determinant on pJJK17 conferred a 30-fold increase in survival and a 200-fold increase in mutability following a UV-B dose of 1,900 J m(-2). In comparative studies using defined genetic constructs, we determined that rulAB restored mutability to the Escherichia coli umuDC deletion mutant RW120 at a level between those of its homologs mucAB and umuDC. Analyses using a rulAB::inaZ transcriptional fusion in Pseudomonas fluorescens Pf5 showed that rulAB was rapidly induced after UV-B irradiation, with expression levels peaking at 4 h. At the highest UV-B dose administered, transcriptional activity of the rulAB promoter was elevated as much as 261-fold compared to that of a nonirradiated control. The importance of rulAB for survival of P. syringae in its phyllosphere habitat, coupled with its wide distribution among a broad range of P. syringae genotypes, suggests that this determinant would be appropriate for continued investigations into the ecological ramifications of mutagenic DNA repair.

Inhibition of tumor necrosis factor-alpha-induced apoptosis by Asparagus cochinchinensis in Hep G2 cells

A human hepatoma cell line, Hep G2 cells, is a reliable system for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Asparagus cochinchinensis(MERRIL) (Liliaceae) roots (ACAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. ACAE (1-100 microg/ml) dose-dependently inhibited the EtOH-induced tumor necrosis factor-alpha (TNF-alpha) secretion. ACAE (1-100 microg/ml) also inhibited the EtOH and TNF-alpha-induced cytotoxicity. Furthermore, we found that ACAE inhibited the TNF-alpha-induced apoptosis of Hep G2 cells. These results suggest that ACAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.

Long-term outcomes of minor dissection at the edge of stents detected with intravascular ultrasound

We evaluated the influences of minor edge dissections on late angiographic in-stent restenosis in 327 patients with 348 lesions (281 lesions without edge dissection and 67 lesions [19.3%] with edge dissection); the angiographic restenosis rate was 29.9% in the lesions with edge dissections versus 25.3% without edge dissections (p = 0.540). The minor non-flow-limiting dissections at the edge of stents may not be associated with the development of late angiographic in-stent restenosis.

An increased rectal maximum tolerable volume and long anal canal are associated with poor short-term response to biofeedback therapy for patients with anismus with decreased bowel frequency and normal colonic transit time

PURPOSE

Biofeedback is an effective therapy for a majority of patients with anismus. However, a significant proportion of patients still failed to respond to biofeedback, and little has been known about the factors that predict response to biofeedback. We evaluated the factors associated with poor response to biofeedback.

METHODS

Biofeedback therapy was offered to 45 patients with anismus with decreased bowel frequency (less than three times per week) and normal colonic transit time. Any differences in demographics, symptoms, and parameters of anorectal physiologic tests were sought between responders (in whom bowel frequency increased up to three times or more per week after biofeedback) and nonresponders (in whom bowel frequency remained less than three times per week).

RESULTS

Thirty-one patients (68.9 percent) responded to biofeedback and 14 patients (31.1 percent) did not. Anal canal length was longer in nonresponders than in responders (4.53 +/- 0.5 vs. 4.08 +/- 0.56 cm; P = 0.02), and rectal maximum tolerable volume was larger in nonresponders than in responders. (361 +/- 87 vs. 302 +/- 69 ml; P = 0.02). Anal canal length and rectal maximum tolerable volume showed significant differences between responders and nonresponders on multivariate analysis (P = 0.027 and P = 0.034, respectively).

CONCLUSIONS

This study showed that a long anal canal and increased rectal maximum tolerable volume are associated with poor short-term response to biofeedback for patients with anismus with decreased bowel frequency and normal colonic transit time.

Generation of monoclonal antibodies to cryptic collagen sites by using subtractive immunization

The extracellular matrix (ECM) plays a fundamental role in the regulation of normal and pathological processes. The most abundantly expressed component found in the ECM is collagen. Triple helical collagen is known to be highly resistant to proteolytic cleavage except by members of the matrix metalloproteinase (MMP) family of enzymes. To date little is known concerning the biochemical consequences of collagen metabolism on human diseases. This is due in part to the lack of specific reagents that can distinguish between proteolyzed and triple helical forms of collagen. Here we used the technique of Subtractive Immunization (SI) to generate two unique monoclonal antibodies (MAbs HUIV26 and HUI77) that react with denatured and proteolyzed forms of collagen, but show little if any reaction with triple helical collagen. Importantly, HUIV26 and HUI77 react with cryptic sites within the ECM of human melanoma tumors, demonstrating their utility for immunohistochemical analysis in vivo. Thus, the generation of these novel MAbs not only identify specific cryptic epitopes within triple helical collagen, but also provide important new reagents for studying the roles of collagen remodeling in normal as well as pathological processes.

The influence of prostate volume on the prostate-specific antigen (PSA) level adjusted for the transition zone volume and free-to-total PSA ratio: a prospective study

OBJECTIVES

To evaluate the influence of prostate volume on the prostate-specific antigen (PSA) level adjusted for the transition zone volume (PSAT) and free-to-total PSA ratio (f/tPSA) in detecting prostate cancer in men with intermediate PSA levels of 4.1-10.0 ng/mL.

PATIENTS AND METHODS

From March 1997 to June 1999, the f/tPSA and PSAT were measured in 105 patients who underwent ultrasound-guided systemic biopsies and had a PSA level of 4.1-10.0 ng/mL, with an apparently normal prostate on a digital rectal examination. The PSAT and f/tPSA were evaluated in all patients and in subgroups of patients with small (< 40 mL) or large (> or = 40 mL) prostates, using receiver operating characteristic (ROC) curves.

RESULTS

Total prostate volume was highly correlated with transition zone volume in all patients and in both subgroups (P < 0.001). In all 105 patients, PSAT had a sensitivity of 82% and its use would have avoided the largest number of unnecessary biopsies (87% specificity) at a threshold value of 0.35 ng. In men with small prostates f/tPSA and PSAT had a high sensitivity and specificity, at threshold values of 0.12 and 0.35 ng, respectively. In large prostates the PSAT was superior to f/tPSA in detecting prostate cancer.

CONCLUSIONS

These results suggest that both f/tPSA and PSAT are useful in detecting prostate cancer in men with small prostates, while PSAT is superior to f/tPSA in detecting prostate cancer in men with large prostates.

The C termini of constitutive nitric-oxide synthases control electron flow through the flavin and heme domains and affect modulation by calmodulin

The sequences of nitric-oxide synthase flavin domains closely resemble that of NADPH-cytochrome P450 reductase (CPR). However, all nitric-oxide synthase (NOS) isoforms are 20-40 residues longer in the C terminus, forming a "tail" that is absent in CPR. To investigate its function, we removed the 33 and 42 residue C termini from neuronal NOS (nNOS) and endothelial NOS (eNOS), respectively. Both truncated enzymes exhibited cytochrome c reductase activities without calmodulin that were 7-21-fold higher than the nontruncated forms. With calmodulin, the truncated and wild-type enzymes reduced cytochrome c at approximately equal rates. Therefore, calmodulin functioned as a nonessential activator of the wild-type enzymes and a partial noncompetitive inhibitor of the truncated mutants. Truncated nNOS and eNOS plus calmodulin catalyzed NO formation at rates that were 45 and 33%, respectively, those of their intact forms. Without calmodulin, truncated nNOS and eNOS synthesized NO at rates 14 and 20%, respectively, those with calmodulin. By using stopped-flow spectrophotometry, we demonstrated that electron transfer into and between the two flavins is faster in the absence of the C terminus. Although both CPR and intact NOS can exist in a stable, one-electron-reduced semiquinone form, neither of the truncated enzymes do so. We propose negative modulation of FAD-FMN interaction by the C termini of both constitutive NOSs.

Targeted antigen delivery to antigen-presenting cells including dendritic cells by engineered Fas-mediated apoptosis

Immunity to tumors as well as to viral and bacterial pathogens is often mediated by cytotoxic T lymphocytes (CTLs). Thus, the ability to induce a strong cell-mediated immune response is an important requirement of novel immunotherapies. Antigen-presenting cells (APCs), including dendritic cells (DCs), are specialized in initiating T-cell immunity. Harnessing this innate ability of these cells to acquire and present antigens, we sought to improve antigen presentation by targeting antigens directly to DCs in vivo through apoptosis. We engineered Fas-mediated apoptotic death of antigen-bearing cells in vivo by co-expressing the immunogen and Fas in the same cell. We then observed that the death of antigen-bearing cells results in increased antigen acquisition by APCs including DCs. This in vivo strategy led to enhanced antigen-specific CTLs, and the elaboration of T helper-1 (Th1) type cytokines and chemokines. This adjuvant approach has important implications for viral and nonviral delivery strategies for vaccines or gene therapies.

Effects of cilostazol on angiographic restenosis after coronary stent placement

This study evaluates the impact of cilostazol on post-stenting restenosis. Cilostazol is a potent antiplatelet agent with antiproliferative properties. Few data are available about the effect of cilostazol on poststenting restenosis. Four hundred nine patients (494 lesions) who were scheduled for elective stenting were randomized to receive aspirin plus ticlopidine (group I, n = 201, 240 lesions) or aspirin plus cilostazol (group II, n = 208, 254 lesions), starting 2 days before stenting. Ticlopidine was given for 1 month and cilostazol for 6 months. Follow-up angiography was performed at 6 months, and clinical evaluation at regular intervals. Baseline characteristics were similar between the 2 groups. The procedural success rate was 99.6% in group I and 100% in group II. There were no cases of stent thrombosis after stenting. Angiographic follow-up was performed in 380 of the 494 eligible lesions and the angiographic restenosis rate was 27% in group I and 22.9% in group II (p = NS). However, diffuse type in-stent restenosis was more common in group I than in group II (54.2% vs 26.8%, respectively, p <0.05). In diabetic patients, the angiographic restenosis rate was 50% in group I and 21.7% in group II (p <0.05). Clinical events during follow-up did not differ between the 2 groups. In conclusion, aspirin plus cilostazol seems to be an effective antithrombotic regimen with comparable results to aspirin plus ticlopidine, but it does not reduce the overall angiographic restenosis rate after elective coronary stenting.

Long-term outcomes of minor plaque prolapsed within stents documented with intravascular ultrasound

The direct relationship between minor plaque prolapsed within stents and late in-stent restenosis is unknown. Therefore, we evaluated the impact of minor plaque prolapse on late angiographic in-stent restenosis. Intravascular ultrasonography (IVUS)-guided single-coronary stenting was successfully performed on 384 consecutive patients with 407 native coronary lesions. Six-month follow-up angiographic evaluation was performed on 315 patients (82. 0%) with 334 lesions (82.1%). Minor plaque prolapsed within the stent was found in 75 of 334 lesions (22.5%). Results were evaluated using angiographic and IVUS methods. The development of minor plaque prolapse was significantly associated with infarct-related artery (P = 0.000) and small pre-intervention minimal lumen diameter (P = 0. 001). The overall angiographic restenosis rate was 23.1% (77/334)-21.3% (16/75) in the lesions with plaque prolapse vs. 23.6% (61/259) in the lesions without plaque prolapse (P = 0.806). In conclusion, minor plaque prolapsed within stents might not be associated with late angiographic in-stent restenosis.

Intravascular ultrasound findings of negative arterial remodeling at sites of focal coronary spasm in patients with vasospastic angina

BACKGROUND

There are few data about the intravascular ultrasound (IVUS) findings in patients with vasospastic angina, especially regarding patterns of vascular remodeling.

METHODS AND RESULTS

Coronary spasm was documented by angiography and electrocardiographic evidence of ischemia in 36 patients after administration of ergonovine (cumulative doses up to 350 microg). After relief of spasm with 1000 microg of intracoronary nitroglycerin, quantitative angiography and IVUS imaging were performed and analyzed by standard methods. The 36 focal spasm sites were compared with the proximal and distal reference segments. The angiographic baseline minimum lumen diameter measured 1.78 +/- 0.66 mm, which decreased to 0.66 +/- 0.38 mm with ergonovine provocation (P <.0001), increased to 2.66 +/- 0.64 mm after intracoronary nitroglycerin (P <.0001 compared with baseline and after ergonovine), and did not change after IVUS imaging (2.66 +/- 0.63, P =.9). By IVUS, atherosclerotic lesions were observed at all coronary spasm sites; the mean plaque burden measured 56% at the spasm site and 35% at the reference. Spasm site plaque composition was hypoechoic in 31 and hyperechoic, noncalcific in 5; there was no calcium. The mean eccentricity index (maximum divided by minimum plaque thickness) was 6.7. Positive remodeling (spasm site arterial area greater than proximal reference) was present in 5; intermediate remodeling (proximal reference greater than spasm site greater than distal reference arterial area) was present in 7; and negative remodeling (spasm site arterial area less than distal reference) was present in 24.

CONCLUSIONS

Sites of vasospasm in patients with variant angina showed characteristics of early atherosclerosis, except for an unusually high incidence of negative arterial remodeling.

Evaluation of individual symptoms cannot predict presence of gastric hypersensitivity in functional dyspepsia

Recently, the concept of gastric hypersensitivity was introduced as an important factor in the pathophysiology of functional dyspepsia (FD), but it is unclear which symptoms can predict the presence of gastric hypersensitivity. Therefore, we evaluated the relationship between common symptoms of FD and various parameters measured by gastric barostat in FD patients. Gastric barostat tests were performed in 64 FD patients and 20 healthy control subjects without gastrointestinal symptoms. Individual symptoms such as early satiety, postprandial fullness, sense of delayed emptying, nausea, vomiting, and epigastric soreness were collected and graded as mild to severe. Basal tone, gastric compliance, and postprandial receptive relaxation were similar in controls and patients, the threshold of abdominal discomfort was lower in FD patients than in controls (8.9 +/- 3.6 mm Hg and 14.5 +/- 3.7 mm Hg, respectively, P < 0.05). However, there were no significant differences in the threshold of abdominal discomfort according to the severity of individual symptoms. In conclusion, a simple evaluation of individual symptoms could not predict the presence of gastric hypersensitivity.

Regional differences in metronidazole resistance and increasing clarithromycin resistance among Helicobacter pylori isolates from Japan

The patterns of antibiotic resistance in Helicobacter pylori were assessed in two different regions in Japan. Overall, prevalences of resistance to metronidazole and clarithromycin were 12.4 and 12.9%, respectively. While there was no difference in clarithromycin resistance, the prevalence of metronidazole resistance was significantly higher in Kyoto (23.8%) than in Sapporo (8.1%). From 1996 to 1999, the prevalence of metronidazole resistance did not change but the prevalence of clarithromycin resistance doubled (from 9.1 to 18.7%).

Inhibitory effect of interleukin-1alpha-induced apoptosis by Polygala tenuifolia in Hep G2 cells

A human hepatoma cell line, Hep G2 cells are reliable for the study of alcohol-induced hepatotoxicity. In this study, we investigated the effect of an aqueous extract of Polygala tenuifolia WILLDENOW (Polygalaceae) roots (PTAE) on ethanol (EtOH)-induced cytotoxicity in Hep G2 cells. PTAE (0.01-1 microg/ml) dose-dependently inhibited the EtOH-induced interleukin-1alpha (IL-1alpha) secretion. PTAE (0.01-1 microg/ml) also inhibited the EtOH- and IL-1alpha-induced cytotoxicity. Furthermore, we found that PTAE inhibited the IL-1alpha-induced apoptosis of Hep G2 cells. These results suggest that PTAE may prevent the EtOH-induced cytotoxicity through inhibition of the apoptosis of Hep G2 cells.

Side-branch occlusion after rotational atherectomy of in-stent restenosis: incidence, predictors, and clinical significance

We evaluated the incidence, predictors, and clinical significance of side-branch occlusion (SBO) after rotational atherectomy (RA) for treatment of in-stent restenosis (ISR) and compared it with those of native coronary artery (NC). RA was performed in 64 patients with 34 ISR (42 side branches) and 30 NC (40 side branches). SBO occurred 14% after RA in ISR group compared with 0% in NC group (P < 0.05), and 33% after adjunctive balloon inflation in ISR group compared with 2.5% in NC group (P < 0.01). Non-Q myocardial infarction developed in seven patients in ISR group and four patients in NC group (P = NS). The presence of significant side-branch (SB) ostial disease (OR = 4.7, P < 0.05) and ISR lesions (OR = 15.5, P < 0.05) were the only independent predictors of SBO by multivariate analysis. The incidence of SBO is higher after RA of ISR than RA of NC and may be associated with an increased risk of non-Q myocardial infarction.

The C terminus of mouse macrophage inducible nitric-oxide synthase attenuates electron flow through the flavin domain

The sequences of nitric-oxide synthase (NOS) flavin domains closely resemble that of NADPH-cytochrome P450 reductase (CPR), with the exception of a few regions. One such region is the C terminus; all NOS isoforms are 20-40 amino acids longer than CPR, forming a "tail" that is absent in CPR. To investigate its function, we removed the 21-amino acid C-terminal tail from murine macrophage inducible NOS (iNOS) holoenzyme and from a flavin domain construct. Both the truncated holoenzyme and reductase domain exhibited cytochrome c reductase activities that were 7-10-fold higher than the nontruncated forms. The truncated holoenzyme catalyzed NO formation approximately 20% faster than the intact form. Using stopped-flow spectrophotometry, we demonstrated that electron transfer into and between the two flavins and from the flavin to the heme domain is 2-5-fold faster in the absence of the C-terminal tail. The heme-nitrosyl complex, formed in all NOS isoforms during NO catalysis, is 5-fold less stable in truncated iNOS. Although both CPR and intact NOS can exist in a stable, one electron-reduced semiquinone form, neither the truncated holoenzyme nor the truncated flavin domain demonstrate such a form. We propose that this C-terminal tail curls back to interact with the flavin domain in such a way as to modulate the interaction between the two flavin moieties.

Topical tretinoin and 5-fluorouracil in the treatment of linear verrucous epidermal nevus

Treatment of a linear verrucous epidermal nevus using topical 0.1% tretinoin cream and 5% 5-fluorouracil in a young patient is described. In 1994, successful topical therapy using this combination was described in the management of an inflammatory linear verrucous epidermal nevus. We report another case in which treatment of a noninflamed epidermal verrucous nevus with 0.1% tretinoin and 5% 5-fluorouracil resulted in significant improvement. An updated summary of the literature discussing management of epidermal nevi is presented.

Postnatal development of parvalbumin and calbindin D-28k immunoreactivities in the canine hippocampus

The calcium-binding proteins, parvalbumin and calbindin D-28k, are markers of different classes of GABAergic interneurons and display different functions. The present study was attempted to determine immunoreactivities and colocalization of the parvalbumin and calbindin D-28k in the developing canine hippocampus by immunohistochemistry. The calcium-binding protein-containing neurons showed different developmental patterns. The first appearance of parvalbumin immunoreactive nonpyramidal cells was observed at P7. Parvalbumin immunoreactivity was elicited by the sequence from CA3 to CA1 to reach an adult-like distribution pattern, which was reached at P60, while calbindin D-28k immunoreactivity appeared from P0, including pyramidal and nonpyramidal cells. The characteristic distribution of calbindin D-28k immunoreactive pyramidal cells was clarified by P28, and an adult-like distribution pattern was reached by the end of the second postnatal month. Double-labeled nonpyramidal cells were frequently seen in the subareas, CA3 of P14/CA1-CA2 of P28, where parvalbumin immunoreactive nonpyramidal cells were emerging. These data suggest that the colocalization of the two calcium-binding proteins during development is related closely to the area-specific maturation of parvalbumin expression, although either prenatal expression of calbindin D-28k or parvalbumin was not determined.

Platelet surface P-selectin molecules increased after exposing platelet to a high shear flow

BACKGROUND

P-selectin is known to play a crucial role in leucocyte recruitment at sites of vascular injury. Although platelet surface expression of P-selectin molecules are well known to occur after platelet stimulation by chemical agonists such as alpha-thrombin, it is still uncertain whether P-selectin expression occurs in the process of the more physiological platelet activation pathway mediated by interaction between von Willebrand factor (vWF) and platelet receptor proteins, including glycoprotein (GP) Ibalpha and GP IIb/IIIa, occurring under high shear rates generated by blood flow.

METHODS

We have developed a method to detect P-selectin molecules expressed on platelet surface with flow-cytometer and monoclonal antibody, which can bind exclusively to P-selectin (WGA1), directly conjugated with fluorescein isothiocynate. This method allowed us to measure platelet surface P-selectin molecules semiquantitatively.

RESULTS

We demonstrated that a significant increase in platelet surface P-selectin molecules occur after exposing platelets to a relatively high shear rate of 10,800 s(-1). We have also demonstrated that shear-induced surface expression of P-selectin as well as microparticle release from platelets depended at least on the interaction between von Willebrand factor and glycoprotein Ibalpha, a platelet surface receptor for the former.

CONCLUSIONS

Shear-induced von Willebrand-mediated surface expression of P-selectin may play a role in leucocyte recruitment in platelet thrombi at vascular injury sites.

Safety and clinical impact of ergonovine stress echocardiography for diagnosis of coronary vasospasm

OBJECTIVES

We sought to address the issues of safety, feasibility and clinical impact of noninvasive diagnosis of coronary vasospasm (CVS).

BACKGROUND

The safety of ergonovine provocation for CVS performed outside the catheterization laboratory has been questioned.

METHODS

We performed a retrospective analysis of the results of bedside ergonovine provocation testing by monitoring left ventricular regional wall motion abnormalities (RWMAs) using two-dimensional echocardiography (Erg Echo).

RESULTS

After confirming that there was no significant epicardial coronary stenosis, Erg Echo was performed on 1,372 patients from July 1991 to December 1997. Ergonovine echocardiography was terminated prematurely in 13 patients (0.9%) because of limitations caused by side effects unrelated to myocardial ischemia. Among 1,359 completed tests, 31% (n = 421) showed positive results, with development of RWMAs in 412 tests (98%) or ST displacement in electrocardiograms of nine tests (2%). Arrhythmias developed in 1.9% (26/1,372), including transient ventricular tachycardia (n = 2) and atrioventricular block (n = 4), which were promptly reversed with nitroglycerin. There was no mortality or development of myocardial infarction. Based on the angiographic criteria of 218 patients, the sensitivity and specificity of Erg Echo for the diagnosis of CVS were 93% and 91%, respectively. Since 1994, Erg Echo has become a more popular diagnostic method than invasive spasm provocation testing in the catheterization laboratory and has comprised more than 95% of all spasm provocation tests during the last three years. In the outpatient clinic, 453 patients underwent Erg Echo safely.

CONCLUSIONS

Although this is a retrospective study in a single center, we believe that Erg Echo is highly feasible, accurate and safe for the diagnosis of CVS and can replace invasive angiographic spasm provocation testing in the catheterization laboratory.

Human chorionic gonadotropin induces nitric oxide synthesis by murine microglia

This study investigated the effects of human chorionic gonadotropin (hCG) on the synthesis of nitric oxide (NO) in murine neonatal microglial cells. When hCG was used in combination with interferon-gamma (IFN-gamma), there was a marked cooperative induction of NO synthesis in a dose-dependent manner. This increase in NO synthesis was reflected as an increased amount of iNOS protein. The increase of NO synthesis by IFN-gamma-plus-hCG was associated with the increase of tumor necrosis factor-alpha (TNF-alpha) secretion and hCG-induced NO production was decreased by the treatment with anti-murine TNF-alpha neutralizing antibody. This study provides evidence that hCG activates expression of iNOS protein in murine microglial cells accompanied by NO accumulation via pathway dependent on L-arginine in the culture medium, and further offers that TNF-alpha acts on the NO synthesis from IFN-gamma-primed murine microglial cells.