Haplotype analysis of the prostacyclin synthase gene and essential hypertension.

Previously, we discovered 3 polymorphisms in the prostacyclin synthase (PGIS) gene: 1) T-192G, in the 5-flanking region, a novel single-nucleotide polymorphism (SNP) that is not associated with essential hypertension (EH); 2) a variable number of tandem repeat (VNTR) polymorphism, 6 nucleotides upstream from the ATG start codon, that is associated with risk of cerebral infarction; and 3) C1117A, in exon 8, an SNP that does not cause an amino acid change in codon 373, and that is associated with risk of myocardial infarction (MI). The purpose of the present study was to establish haplotypes of the PGIS gene consisting of these 3 polymorphisms, and to assess the association between these haplotypes and EH. We detected 19 haplotypes. There was no significant difference in the overall distribution of haplotypes between EH and normotensive subjects. To summarize, we successfully identified haplotypes of the PGIS gene, and these haplotypes were not associated with EH.     

Noninvasive coronary artery imaging by multislice spiral computed tomography.

Although the excellent spatial resolution of multislice spiral computed tomography (MSCT) enables the coronary arteries to be visualized, its limited temporal resolution results in poor image reproducibility because of cardiac motion artifact (CMA) and hence limits its widespread clinical use. A novel retrospectively ECG-gated reconstruction method has been developed to minimize CMA. In 88 consecutive patients, the scan data were reconstructed using 2 retrospectively ECG-gated reconstruction methods. Method 1: the end of the reconstruction window (250 ms) was positioned at the peak of the P wave on ECG, which corresponded to the end of the slow filling phase during diastole immediately before atrial contraction. Method 2 (conventional method): relative retrospective gating with 50% referred to the R-R interval was performed so that the beginning of the reconstruction window (250 ms) was positioned at the halfway point between the R-R intervals of the heart cycle. The quality of the coronary artery images was evaluated according to the presence or absence of CMA. The assessment was applied to the left main coronary artery (LMCA), the left anterior descending artery (LAD, segments #6, #7 and #8), the left circumflex artery (LCx, segments #11 and #13) and the right coronary artery (RCA, segments #1, #2 and #3). The first diagonal artery (#9-1), the obtuse marginal artery (#12-1), the posterior descending artery (#4-PD), the atrioventricular node branch (#4-AV) and the first right ventricular branch (RV) were also evaluated. Of the 88 patients, 85 were eligible for image evaluation. Method 1 allowed visualization of the major coronary arteries without CMA in the majority of patients. The LCA system (segments #5-7, #11 and #13) and the proximal portion of the RCA were visualized in more than 94% of patients. Artifact-free visualization of the distal portion of the LAD (segment #8) and RCA (#4PD and #4AV), and side branches (#9-1, #12-1 and RV) was also achieved in more than 80% of patients. On the other hand, CMA occurred frequently on images obtained by Method 2. The LCx and RCA systems were the most affected by CMA, revealing only 41% artifact-free visualization of the segment #13, 39% of #1, 15% of #2 and 32% of #3. Thus, Method 1, which avoids the ventricular motion occurring during the rapid filling and atrial contraction phases, gives superior image quality over the conventional ECG-gated reconstruction method.     

Limited maximal vasodilator capacity of forearm resistance vessels in patients with hypertrophic cardiomyopathy

Summary It is not known whether hypertrophic cardiomyopathy (HCM) is accompanied by an abnormality in vascular smooth muscles. In this study, we examined the maximal vasodilator capacity of forearm resistance vessels by measuring minimal forearm vascular resistance (min. FVR) during peak reactive hyperemia after 10 min of arterial occlusion in patients with HCM (n=15, 41±4 years old) and age-matched control subjects (n=12, 42±3 years old). Forearm blood flow (FBF) was measured by a mercury-in-silastic strain gauge plethysmograph and FVR was calculated by dividing mean blood pressure by FBF. Resting FBF was lower (P<0.05) and resting FVR was higher (P<0.01) in patients with HCM than in control subjects. Min. FVR was significantly greater in patients with HCM than in control subjects (2.7±0.2 vs 1.5±0.2 units,P<0.005). We also examined vasoconstrictive responses to intra-arterially infused angiotensin II (20 and 40 ng/min); responses were greater in patients with HCM than in control subjects (P<0.05). These results indicate that forearm circulation is altered in patients with HCM. The result that the maximal vasodilator capacity of forearm resistance vessels is limited in patients with HCM as compared with that in age-matched control subjects suggests that there may be abnormalities in forearm resistance vessels in patients with HCM, which might involve increased wall thickness or intrinsic abnormalities in vascular smooth muscle.     

Pyogenic granuloma of the stomach successfully treated by endoscopic resection after transarterial embolization of the feeding artery

Pyogenic granulomas represent the aquisition of vasodilative granulation tissue in the skin or mucosa. They are extremely rare in the alimentary tract, other than in the oral cavity. Here, we report a case of pyogenic granuloma arising from the gastric mucosa. An 82-year-old man was admitted to our hospital because of melena of more than 3 months, duration. Esophagogastroduodenoscopy (EGD) revealed a 30-mm-diameter semipedunculated lesion with an irregular surface in the fundus of the stomach. During hospitalization, the patients anemia worsened due to loss of blood from the lesion, with the level of hemoglobin declining to 6g/dl, and a blood transfusion was required. Because radiological and endoscopic findings indicated the lesion was hypervascular, transarterial embolization of the nutritional artery of the lesion was performed before endoscopic resection of the lesion. One week after the embolotherapy, endoscopic mucosal resection was performed, without any complications, such as massive bleeding. Histological studies of the resected specimen revealed many capillaries of various sizes, lined with plump endothelial cells, and accompanied by acute and chronic inflammatory infiltrates. On the basis of these observations, the lesion was diagnosed as a pyogenic granuloma. One year later, the patient was asymptomatic and there was no evidence of tumor recurrence on follow-up EGD.     

Effect of 60 Minutes of Rapid Atrial Pacing on Atrial Action Potential Duration in the In-Situ Canine Heart

Right atrial monophasic action potentials were recorded before and after 60 minutes of rapid atrial pacing (pacing cycle length (CL); 127 ± 10 ms) in 12 closed-chest dogs. The right atrial (RA) monophasic action potential (MAP) duration at 90% repolarization (RAMAPD) was measured at CLs of 400 ms and 250 ms. CL-dependent changes in RAMAPD (CL 400 ms – 250 ms) before and after rapid atrial pacing were 24 ± 1 ms and 16 ± 5 ms, respectively (p < 0.02). RAMAP was recorded at each atrial pacing CL starting at 240 ms decreasing by 10-ms increments. RAMAPD alternans was observed in 10 of 12 dogs at a CL of 163 ± 17 ms before and in 10 of 12 dogs at s CL of 198 ± 29 ms (p < 0.01) after rapid atrial pacing. Sustained atrial fibrillation (AF) (>5 minutes) was induced in 1 of 12 dogs at a pacing CL of 130 ms before rapid atrial pacing and in 4 of 12 dogs at a pacing CL of 135 ± 17 ms after rapid atrial pacing. Onset of AF was always preceded by the RAMAPD alternans. Sixty minutes of rapid atrial pacing leads to diminution of rate adaptation of atrial action potential duration (APD) and appearance of APD alternans of greater magnitude at longer CL, both of which may contribute to the initiation and perpetuation of AF during its early phase.     

Unexpected coronary vasospasm of a contralateral artery during balloon angioplasty

It is unusual for coronary vasospasm to develop following angioplasty of a coronary vascular lesion that is located elsewhere. We experienced a rare case of shock with vasospasm of the right coronary artery in a patient following balloon angioplasty performed for stent restenosis of the left anterior descending artery.     

Asymptomatic fascioliasis

A 72-year-old Japanese man displayed asymptomatic eosinophilia for 4 months. Computed tomography showed multiple space-occupying lesions in the liver. Zoonotic liver flukes were suspected based on occupational exposure to cattle, serological and radiological findings. Immunological examination was helpful in diagnosing the disease and laparoscopy was crucial in confirming Fasciola hepatica and excluding the possibility of malignant hepatic tumors. Human fascioliasis was finally diagnosed and praziquantel administered. Blood eosinophilia resolved within 4 months and liver tumors almost disappeared within 12 months. From our experience, laparoscopy with liver biopsy is very important for diagnosing human fascioliasis, particularly for asymptomatic fascioliasis.     

Platelet-associated anti-GPIIb-IIIa autoantibodies in chronic immune thrombocytopenic purpura recognizing epitopes close to the ligand-binding site of glycoprotein (GP) IIb

Localization of epitopes for platelet-associated (PA) anti-GPIIb-IIIa (alpha(IIb)beta(3)) autoantibodies in chronic immune thrombocytopenic purpura remains elusive. Previous studies suggest that PA antibodies recognize the tertiary structure of intact glycoprotein (GP) IIb-IIIa. To localize their epitopes using antigen-capture enzyme-linked immunosorbent assay (ELISA), the reactivity of 34 PA anti-GPIIb-IIIa antibodies was examined with recombinant GPIIb-IIIa having a defect in ligand-binding sites in either GPIIb or GPIIIa, and no major conformational change was induced: KO variant GPIIb-IIIa was attributed to a 2-amino acid insertion between residues 160 and 161 in the W3 4-1 loop in GPIIb, and CAM variant GPIIb-IIIa was attributed to D119Y in GPIIIa. In one third (11 of 34) of the patients, PA antibodies showed a marked decrease (less than 50%) in reactivity with KO compared with wild-type GPIIb-IIIa. Their reactivity was also impaired against GPIIbD163A-IIIa. In sharp contrast, they reacted normally with CAM GPIIb-IIIa. OP-G2, a ligand-mimetic monoclonal antibody, markedly inhibited their binding to GPIIb-IIIa in patients with impaired binding to KO GPIIb-IIIa, but small GPIIb-IIIa antagonists did not. In addition, a newly developed sensitive ELISA indicated that autoantibodies showing impaired binding to KO are more potent inhibitors for fibrinogen binding. The present data suggest that certain PA anti-GPIIb-IIIa autoantibodies recognize epitopes close to the ligand-binding site in GPIIb, but not in GPIIIa.     

A case of vasospastic angina showing resolution of coronary vasospasm in acetylcholine provocation test corresponding to regression of coronary atherosclerosis

To the best of our knowledge this case is the first case of INVM presented with typical angina and ischemic ECG findings without atherosclerotic narrowing but a myocardial bridge in the midportion of the left anterior descending artery documented with coronary angiography.