Cardiovascular risk factors and underlying pathology and prevalence of lipid plaques in women with acute coronary syndromes in different age groups

Background

An incidence of cardiovascular events increases with age in women. The relationship between cardiovascular risk factors, and the underlying pathology and the prevalence of lipid plaques has not been systematically studied in different age groups in women presented with acute coronary syndromes (ACS).

Purpose

We investigated the underlying pathology and the prevalence of lipid plaques in culprit lesions by optical coherence tomography (OCT) in women with different risk factors.

Methods

A total of 382 women who underwent pre-intervention OCT imaging were included. The underlying pathology and the prevalence of lipid plaques in the culprit lesion was compared between women with and without cardiovascular risk factors (i.e. hypertension, smoking, hyperlipidemia, diabetes mellitus, family history and chronic kidney disease) in three different age groups (<60 yr, 60–70 yr, >70 yr).

Results

The relative prevalence of plaque erosion was higher in younger women (<60 yr) and decreased with age (from 51% to 28%, p<0.001). There was no significant difference in the prevalence of lipid plaques between women with and without risk factors, except a higher prevalence of lipid plaques in current smokers compared to non-smokers (79% vs. 63%, p=0.003). In women with hyperlipidemia, the prevalence of lipid plaques was modest in young ages (<60 yr), but increased steeply with age (p<0.001). The increasing age trend for lipid plaque was also observed in women with hypertension (p=0.03) and current smokers (p=0.01). In women with diabetes mellitus and family history, the prevalence of lipid plaques was high even in young ages (<60 yr) and did not increase with age.

Conclusion

The prevalence of plaque erosion was higher in younger women (<60 yr) and decreased with age. Current smokers had significantly higher prevalence of lipid plaque. Patients with diabetes and positive family history had a higher prevalence of lipid plaque at young age. The prevalence of lipid plaques increased with age particularly in women with hyperlipidemia and hypertension.

Funding Acknowledgement

Type of funding sources: Foundation.

Predictors for rapid progression of coronary calcification: an optical coherence tomography (OCT) study

Background

The natural progression of coronary calcification has not been systematically studied. In vivo coronary calcium can be evaluated by OCT.

Purpose

To identify the incidence and predictors for rapid progression of coronary calcification.

Methods

Patients with serial OCT imaging at baseline and at 6 months were selected from our database. Changes in calcium index during 6-month follow-up and predictors for progression of calcification were studied. Calcium index was defined as the product of the mean calcium arc and calcium length. Rapid progression of calcification was defined as an increase in calcium index above the median value.

Results

Among 187 patients who had serial OCT imaging, 235 calcified plaques were identified in 108 patients (57.8%) at baseline with median calcium index of 132.0 (Interquartile range 58.5–281.2). After 6 months, the calcium index increased in 95.3% of calcified plaques from 132.0 to 178.2 (p<0.001). In multivariable analysis, diabetes mellitus (DM), chronic kidney disease (CKD), lipid-rich plaque, and macrophages were found to be independent predictors for rapid progression of coronary calcification (table). Interestingly, rapid progression of calcification was associated with a significant reduction of inflammatory features (thin-cap fibroatheroma [TCFA]; baseline 21.2% vs. follow-up 11.9%, p=0.003, macrophages; baseline 74.6% vs. follow-up 61.0%, p=0.001).

Conclusions

This study demonstrated that DM, CKD, lipid-rich plaque, and macrophages were independent predictors for rapid progression of coronary calcification. High level of vascular inflammation may stimulate rapid progression of calcification.

Funding Acknowledgement

Type of funding source: None

Predictors of rapid plaque progression: an optical coherence tomography study

Background

Two patterns of plaque progression have been described: slow linear progression and rapid step-wise progression. The former will cause stable angina when the narrowing reaches a critical threshold, while the latter may lead to acute coronary syndromes or sudden cardiac death.

Purpose

The aim of the study was to identify morphologic predictors for rapid plaque progression.

Methods

Patients who had OCT imaging during the index procedure and follow-up angiography with a minimum of 6-month interval were selected. Non-culprit lesion was defined as a plaque with a diameter stenosis ≥30% on index angiogram. Lesion progression was defined as the decrease of angiographic minimum lumen diameter ≥0.4 mm at follow-up (mean, 7.1 months). Baseline morphological characteristics of the plaques with rapid progression were evaluated by OCT. In a subgroup with follow-up OCT imaging for plaques with progression, morphological changes from baseline to follow-up were assessed.

Results

Among 517 lesions, 50 lesions showed progression. These lesions had a significantly higher prevalence of lipid-rich plaque (76.0% vs. 50.5%), thin-cap fibroatheroma (TCFA) (20.0% vs. 5.8%), layered plaque (60.0% vs. 34.0%), macrophage accumulation (62.0% vs. 42.4%), microvessel (46.0% vs. 29.1%), plaque rupture (12.0% vs. 4.7%), and thrombus (6.0% vs. 1.1%), compared to those without progression. The multivariable analysis identified lipid-rich plaque [odds ratio (OR) 2.17, 95% confidence interval (CI) 1.02–4.62, p=0.045], TCFA (OR 5.85, 95% CI 2.01–17.03, p=0.001), and layered plaque (OR 2.19, 95% CI 1.03–4.17, p=0.040) as predictors of subsequent lesion progression. In a subgroup with follow-up OCT, a new layer was detected in 14/41 (34.1%) plaques.

Conclusions

Lipid-rich plaque, TCFA, and layered plaque were predictors of subsequent rapid plaque progression. A new layer, a signature of rapid progression through plaque disruption and healing, was detected in 1/3 of the cases.

Funding Acknowledgement

Type of funding source: None

Circadian variations in pathogenesis of ST-segment elevation myocardial infarction

Background

Previous studies have reported a circadian variation in the onset of ST-segment elevation myocardial infarction (STEMI). However, underlying mechanisms for the circadian variation have not been fully elucidated.

Purpose

We investigated the relationship between onset of STEMI and the underlying pathology using optical coherence tomography (OCT).

Methods

Patients presenting with STEMI were selected from an international, multi-center, longitudinal registry study, which included patients who underwent OCT imaging of the culprit lesion at 11 institutions in 6 countries. Onset of MI was estimated using the time of OCT imaging. Patients were divided into 4 groups based on the estimated time of onset (00:00–05:59, 06:00–11:59, 12:00–17:59, or 18:00–23:59). Underlying pathologies of MI (plaque rupture, plaque erosion, and calcified plaque) were compared among the 4 groups.

Results

Among 648 patients, plaque rupture was diagnosed in 386 patients (59.6%), plaque erosion in 197 patients (30.4%), and calcified plaque in 65 patients (10.0%). A marked circadian variation was detected in the incidence of plaque rupture with a peak at 9:00, whereas it was not evident in plaque erosion or calcified plaque. The probability of plaque rupture increased in the periods of 06:00–11:59 (odds ratio: 2.13, 95% confidence interval: 1.30 to 3.49, p=0.002) and 12:00–17:59 (odds ratio: 2.10, 95% confidence interval: 1.23 to 3.58, p=0.005), compared to the period of 00:00–05:59. This circadian pattern was observed only during weekdays (p=0.013) and it was not evident during the weekend (p=0.742).

Conclusions

Plaque rupture occurred most frequently in the morning and the circadian variation was evident only during the weekdays. Acute MI caused by plaque rupture may be related to catecholamine surge.

Funding Acknowledgement

Type of funding source: None

P2651Seasonal variations in the pathogenesis of acute coronary syndromes

Background

Seasonal variations in acute coronary syndrome (ACS) has been known with the winter being the peak in incidence and mortality. However, underlying pathophysiology for this variation has not been studied.

Purpose

We sought to compare pathobiology of the culprit lesions assessed by optical coherence tomography (OCT) among the four seasons.

Methods

Patients with ACS who underwent OCT were recruited from 6 countries in the Northern Hemisphere. The prevalence of 3 most common pathologies, plaque rupture, plaque erosion and calcified plaque, and other features of coronary plaques were compared among the four seasons.

Results

In 1113 patients with ACS, 284 (25%) patients were admitted in spring, 243 (22%) patients in summer, 290 (26%) patients in autumn and 296 (27%) patients in winter. The proportion of underlying 3 pathologies was significantly different in each season (prevalence of plaque rupture, plaque erosion, calcified plaque was 50%, 39%, and 11%, respectively in the spring; 44%, 43%, and 13% in the summer; autumn: 49%, 39%, and 12% in the autumn; 57%, 30%, and 13% in the winter; P=0.039). The proportion of plaque rupture was higher in winter but lower in summer, and that of plaque erosion was higher in summer, but lower in winter. Maximum and minimum temperatures on the day of OCT procedure were significantly lower in the plaque rupture group than in the plaque erosion group (P=0.02 and P=0.012, respectively). In the rupture group, the prevalence of hypertension was significantly higher in winter, but in the erosion group, it was not different among the four seasons.

Figure 1. The proportion of culprit lesion characteristics were significantly different among the 4 season groups. (P=0.039) The proportion of plaque rupture was significantly higher in winter but lower in summer. In contrast, the proportion of plaque erosion was higher in summer, but lower in winter.

Conclusions

Seasonal variation of the underlying mechanisms of ACS reflects different pathobiology. The proportion of plaque rupture is highest in winter and the proportion of plaque erosion is highest in summer. A different approach may be needed for the prevention and treatment of ACS depending on the season of its occurrence.

P5626The clinical impact of the angle of OCT detected irregular protrusion after primary PCI at the STEMI culprit lesions

Background and introduction

The percutaneous coronary intervention (PCI) for acute coronary syndrome (ACS) shows worse clinical outcomes than that for stable angina. As the one of the reasons, a recent optical coherence tomography (OCT) registry showed that the presence of irregular protrusion (IP)after coronary stenting was the worse predictor of 1-year device-oriented clinical end points. However, the impact of the quantitative findings on IP has not been well investigated in ACS patients.

Aim

To investigate the clinical impact of the post stent OCT findings, especially IP, detected by OCT after coronary stenting in ACS patients.

Methods

Consecutive 256 ACS lesions treated with OCT-guided PCI in our Medical University Hospital from January 2013 to November 2016 was retrospectively analyzed. In 256 lesions, 173 lesions were enrolled which had ST-elevation acute myocardial infarction (STEMI) with the onset to recanalization time within 720 minutes. In 170 lesions, the OCT images were available. In OCT image, IP was detected in 140 lesions (82.3%). Quantitative analysis of IP in post-procedure OCT imaging was observed to identify the OCT predictors for clinical endpoint including cardiac death, target vessel revascularization ant stent thrombosis in 1 year after index PCI.

Result

In post-procedure OCT findings, stent edge dissection was detected in 32.4% of lesions. Incomplete stent apposition was detected in 74.1%. Maximum angle of irregular protrusion was 194±86 degree and the incidence of maximum IP angle >180 degree was 52.9%. Maximum height of IP was 0.26±0.11mm. Small minimal stent area, defined as a lesion with minimal stent area <5.0 mm2 in a drug-eluting stent or <5.6 mm2 in a bare metal stent, was observed in 32.4% of lesions. Maximum IP angle and that of >180degree was significantly associated with the clinical endpoint (p=0.0259 and 0.0429, respectively).

Conclusion

In STEMI patients, IP was frequently observed in post-procedure OCT imaging during primary PCI. The maximum angle of IP was significantly associated with the clinical end points. The prognostic impact of maximum IP angle in STEMI patient needs further investigations.

P5502Comparison of clinical characteristics and prognosis between non-octogenarians and octogenarians with cardiac troponin positive acute myocardial infarction

Background

Cardiac troponin (cTn) is the preferred biomarker for the diagnosis of acute myocardial infarction (AMI). Octogenarians who presented cTn positive AMI are not usually recruited in clinical trials. Therefore, their clinical characteristics and prognosis are rarely investigated.

Objective

To study the characteristics and prognosis in octogenarians who presented cTn positive AMI.

Methods and results

The Japanese registry of acute Myocardial INfarction diagnosed by Universal dEfiniTion (J-MINUET) is a prospective and multicenter registry. A total of 3,283 consecutive AMI patients who were diagnosed by cTn-based criteria were included. The patients were divided into non-octogenarians (n=2,593) and octogenarians (n=690). Compared with non- octogenarians, octogenarians showed significantly lower incidence of diabetes mellitus (37.6% and 31.9%, p=0.006) and dyslipidemia (53.6% and 45.6%, p<0.001), and significantly higher incidence of hypertension (64.1% and 75.3%, p<0.001) and chronic kidney disease (38.7% and 68.7%, p<0.001). Octogenarians showed significantly longer onset to door time (p<0.001) and longer door to device time (p<0.001). Though, compared with non-octogenarians, octogenarians showed lower peak CK (2,506 and 1,926, p<0.001), LVEF was significantly lower in octogenarians (54.6% and 52.6%, p=0.005). The presentation of AMI was different between the two group. The incidence of ST-segment elevation MI (STEMI) was 70.7% in non-octogenarians and 62.0% in octogenarians. Non-STEMI with CK elevation and without CK elevation were 16.2% and 13.1% in non- octogenarians, and 20.9% and 17.1% in octogenarians. In-hospital mortality was higher in octogenarians (4.7% and 13.2%, P<0.001). Especially, octogenarians with STEMI and non-STEMI with CK elevation showed the highest in-hospital mortality. And octogenarians without CK elevation showed similar in hospital mortality with non-octogenarians with STEMI (Figure).

Conclusions

J-MINUET showed the poor prognosis of octogenarians who were diagnosed as AMI based on cTn.

Acknowledgement/Funding

None

Emicizumab, the bispecific antibody to factors IX/IXa and X/Xa, potentiates coagulation function in factor XI-deficient plasma in vitro

Essentials Emicizumab mimics factor (F)VIIIa cofactor function, augments the intrinsic tenase activity. We assessed the emicizumab-driven hemostatic function in FXI-deficient plasmas. Emicizumab improved the coagulation potentials in severe FXI-deficient plasma. Emicizumab may provide a possibility for clinical application in patients with FXI deficiency. SUMMARY: Background Patients with factor (F)XI deficiency commonly present with markedly prolonged activated partial thromboplastin times (APTT), although bleeding phenotypes are heterogeneous. Emicizumab, a bispecific monoclonal antibody to FIX/FIXa and FX/FXa, mimics FVIIIa cofactor function on phospholipid (PL) surfaces. Antibody reactions were designed, therefore, to augment mechanisms during the propagation phase of blood coagulation. Aim To assess emicizumab-driven hemostatic function in FXI-deficient plasmas. Methods and Results Standard ellagic acid (Elg)/PL-based APTTs of different FXI-deficient plasmas (n = 13; FXI activity, < 1 IU dl-1 ) were markedly shortened dose dependently by the presence of emicizumab. To further analyze the effects of emicizumab, clot waveform analysis (CWA) in FXI-deficient plasmas with emicizumab, triggered by tissue factor (TF)/Elg demonstrated improvements in both clot times, reflecting the initiation phase, and coagulation velocity, which represents the propagation phase. Emicizumab also enhanced the TF/Elg-triggered thrombin generation in FXI-deficient plasmas dose-dependently although the degree of enhancement varied in individual cases. Thrombin generation with either FVII-deficient plasma or FIX-deficient plasma treated with anti-FXI antibody showed little or no increase by the co-presence of emicizumab, suggesting that the accelerated thrombin generation in FXI-deficient plasmas by emicizumab should depend on the FIXa-involved coagulation propagation initially triggered by FVIIa/TF. The ex vivo addition of emicizumab to whole blood from three patients with severe FXI deficiency demonstrated modest, dose-dependent improvements in Ca2+ -triggered thromboelastograms (NATEM mode). Conclusion Emicizumab appeared to improve coagulation function in severe FXI-deficient plasma, and might provide possibilities for clinical application in patients with FXI deficiency.

Routine measurements of factor VIII activity and inhibitor titer in the presence of emicizumab utilizing anti-idiotype monoclonal antibodies

Essentials Emicizumab (Emi) affects the APTT-based assays of factor (F)VIII activity and inhibitor titer. A mixture of two anti-Emi monoclonal antibodies (mAb) effectively neutralized the Emi activity. Anti-Emi mAbs completely eliminated the influence of Emi on FVIII activity and inhibitor titer. The inclusion of anti-Emi mAbs in routine FVIII assays would be useful for Emi-treated patients.

SUMMARY

Background Emicizumab is an anti-factor (F)IXa/X bispecific monoclonal antibody (mAb), mimicking the factor (F)VIIIa cofactor activity. Emicizumab does not require activation by thrombin and its shortening effect on the activated partial prothrombin time (APTT) is more pronounced than that of factor (F)VIII. APTT-based FVIII activity (FVIII:C) and FVIII inhibiter titer measurements are influenced by the presence of emicizumab. Aim To establish a reliable APTT-based assay to measure FVIII in the presence of emicizumab. Methods Plasmas from hemophilia A (HA) patients without or with inhibitors were studied using one-stage FVIII:C and Bethesda inhibitor assays. Two recombinant anti-idiotype mAbs to emicizumab (anti-emicizumab mAbs) were prepared, rcAQ8 to anti-FIXa-Fab and rcAJ540 to anti-FX-Fab. Results The combined anti-idiotype mAbs (2000 nm each) eliminated the effects of emicizumab on APTTs of HA plasmas without or with inhibitor by competitive inhibition of antibody binding to FIX(a)/FX(a). Measurements of FVIII coagulation activity in HA plasmas without inhibitor were overestimated in the presence of emicizumab (1 μm = ~150 μg mL-1 ) at all reference levels of FVIII. The addition of anti-emicizumab mAbs to the assay mixtures completely neutralized the emicizumab and facilitated accurate determination of FVIII:C. Anti-FVIII inhibitor titers were undetectable in the presence of emicizumab in HA plasmas with inhibitor or normal plasmas mixed with anti-FVIII neutralizing antibodies. These effects of emicizumab were completely counteracted by the addition of the anti-idiotype mAbs, allowing accurate assessment of inhibitor titers. Conclusion The in vitro inclusion of anti-emicizumab mAbs in the standard one-stage coagulation assays prevented interference by emicizumab and enabled accurate measurements of FVIII:C and inhibitor titers.

Modified clot waveform analysis to measure plasma coagulation potential in the presence of the anti-factor IXa/factor X bispecific antibody emicizumab

Essentials The activated partial prothrombin time (aPTT) cannot predict the activity of emicizumab (Emi). Adjusted clot waveform analyses using a prothrombin time (PT)/aPTT initiator were developed. Activity of Emi in the co-presence of factor VIII or bypassing agents was quantified. This assay is useful for assessing coagulation potential in Emi-treated hemophilia A.

SUMMARY

Background Emicizumab is an anti-activated factor IX/FX bispecific antibody that mimics activated FVIII cofactor function. Emicizumab does not require activation by thrombin, and its effect on shortening the activated partial thromboplastin time (APTT) is much greater than that of FVIII. Therefore, the APTT has limited utility in hemophilia A (HA) patients treated with emicizumab. Aim To evaluate the global coagulation potential of emicizumab. Methods Clot waveform analysis (CWA) with prothrombin time (PT)/APTT mixed reagents was used to define hemostatic monitoring protocols in HA patients. A modified parameter, adjusted-|min1| (Ad|min1|), was developed. Maximum and minimum percentage transmittance were defined as 100% and 0% in the precoagulation and postcoagulation phases, respectively. Ad|min1| was calculated as an index of the maximum velocity of the coagulation process. Results Ad|min1| obtained with mixed-trigger reagent (PT/APTT/buffer, 1 : 15 : 135) in the presence of emicizumab optimally corresponded to the conversion rate estimated in animals; 0.2-0.4 IU dL-1 equivalent FVIII per 1 μg mL-1 emicizumab). Ex vivo addition of emicizumab to HA plasma with or without inhibitors resulted in concentration-dependent increases in Ad|min1|, with some individual variations. The addition of various concentrations of FVIII to HA plasma mixed with emicizumab resulted in dose-dependent increases in Ad|min1|. Similarly, mixtures of activated prothrombin complex concentrate and emicizumab added to HA plasma resulted in dose-dependent increases in Ad|min1|. In contrast, enhanced coagulation potential appeared to be better defined by the clot time than by Ad|min1| in experiments using recombinant activated FVII. Conclusion The PT/APTT reagent-triggered adjusted CWA could provide a useful means of assessing global coagulation potential in emicizumab-treated HA patients, with enhanced activity neither masking nor being masked by FVIII or bypassing agents.

A possible role of low regulatory T cells in anti-acetylcholine receptor antibody positive myasthenia gravis after bone marrow transplantation

BACKGROUND

Chronic graft-versus-host disease (GVHD) appears several months following allogenic hematopoietic stem cell transplantation (HSCT) and is clinically analogous to autoimmune disorder. Polymyositis is a common neuromuscular disorder in chronic GVHD, but myasthenia gravis (MG) is extremely rare. Hence, its pathophysiology and treatment have not been elucidated.

CASE PRESENTATION

A 63-year-old man with a history of chronic GVHD presented with ptosis, dropped head, and dyspnea on exertion, which had worsened over the previous several months. He showed progressive decrement of compound muscle action potential in the deltoid muscle evoked by 3-Hz repetitive nerve stimulation, a positive edrophonium test, and elevated levels of serum anti-acetylcholine receptor antibodies, which suggested a diagnosis of generalized MG. No thymoma was found. Flow cytometric analysis revealed a remarkable depletion of peripheral Tregs (CD4⁺CD25^highFOXP3⁺ cells, 0.24% of the total lymphocytes). Administration of prednisolone and tacrolimus was insufficient to alleviate his symptoms; however, the use of rituximab successfully improved his condition.

CONCLUSIONS

Myasthenic symptoms appeared in the process of tapering prednisolone for the treatment of chronic GVHD, supporting the diagnosis of MG associated with chronic GVHD. The present case proposes a possibility that reduction of Tregs might contribute to the pathogenesis of MG underlying chronic GVHD. Immunotherapy with rituximab is beneficial for treatment of refractory MG and GVHD.

Cauda equina involvement in post-radiation lower motor neuron syndrome

Post-radiation lower motor neuron syndrome (PRLMNS) is a rare neurological complication of radiation therapy and its pathogenesis is unclear. We herein report a patient with PRLMNS who developed leg weakness 17 years after craniospinal radiation as a treatment for suprasellar germinoma. The electrophysiological evaluation, via a novel magnetic stimulation method, indicated a prolonged cauda equina conduction time, suggesting focal demyelination of the nerve roots in the cauda equina. The distribution of the denervated muscles detected by magnetic resonance imaging was consistent with patchy motor nerve root lesions. These results support the hypothesis that PRLMNS originates from ischemic radiculopathy in the cauda equina.

Anti-factor IXa/X bispecific antibody (ACE910): hemostatic potency against ongoing bleeds in a hemophilia A model and the possibility of routine supplementation

BACKGROUND

We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation.

OBJECTIVES

To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use.

METHODS

A non-human primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed.

RESULTS

A single bolus of 1 or 3 mg kg-1 ACE910 showed hemostatic activity comparable to that of 10 U kg-1 (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis.

CONCLUSIONS

ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.

Anti-factor IXa/X bispecific antibody (ACE910): hemostatic potency against ongoing bleeds in a hemophilia A model and the possibility of routine supplementation

BACKGROUND

We previously reported that a humanized anti-factor IXa/X bispecific antibody, hBS23, mimics the function of FVIII even in the presence of FVIII inhibitors, and has preventive hemostatic activity against bleeding in an animal model of acquired hemophilia A. After further molecular engineering of hBS23, we recently identified an improved humanized bispecific antibody, ACE910, for clinical investigation.

OBJECTIVES

To elucidate the in vivo hemostatic potency of ACE910 by examining its effect against ongoing bleeds, and to determine its pharmacokinetic parameters for discussion of its potency for prophylactic use.

METHODS

A nonhuman primate model of acquired hemophilia A was established by injecting anti-primate FVIII neutralizing antibody. When bleeds emerged following an artificial bleed-inducing procedure, either ACE910 or recombinant porcine FVIII (rpoFVIII) was intravenously administered. rpoFVIII was additionally administered twice daily on the following 2 days. Bleeding symptoms were monitored for 3 days. A pharmacokinetic study and multiple-dosing simulations of ACE910 were also performed.

RESULTS

A single bolus of 1 or 3 mg kg⁻¹ ACE910 showed hemostatic activity comparable to that of 10 U kg⁻¹ (twice daily) rpoFVIII against ongoing bleeds. The determined ACE910 pharmacokinetic parameters included a long half-life (3 weeks) and high subcutaneous bioavailability (nearly 100%). The simulation results based on pharmacokinetic parameters indicated that the above hemostatic level could be maintained with once-weekly subcutaneous administration of ACE910, suggesting the possibility of more effective prophylaxis.

CONCLUSIONS

ACE910 may offer an alternative on-demand treatment option for patients with hemophilia A, as well as user-friendly and aggressive routine supplementation.

Aquaporin-4 expression in distal myopathy with rimmed vacuoles

Background

Distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy is clinically characterized by the early involvement of distal leg muscles. The striking pathological features of the myopathy are muscle fibers with rimmed vacuoles. To date, the role of aquaporin-4 water channel in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy has not been studied.

Case presentation

Here, we studied the expression of aquaporin-4 in muscle fibers of a patient with distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy. Immunohistochemical and immunofluorescence analyses showed that sarcolemmal aquaporin-4 immunoreactivity was reduced in many muscle fibers of the patient. However, the intensity of aquaporin-4 staining was markedly increased at rimmed vacuoles or its surrounding areas and in some muscle fibers. The fast-twitch type 2 fibers were predominantly involved with the strong aquaporin-4-positive rimmed vacuoles and TAR-DNA-binding protein-43 aggregations. Rimmed vacuoles with strong aquaporin-4 expression seen in the distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy patient were not found in control muscles without evidence of neuromuscular disorders and the other disease-controls.

Conclusions

Aquaporin-4 might be crucial in determining the survival or degeneration of fast-twitch type 2 fibers in distal myopathy with rimmed vacuoles/hereditary inclusion body myopathy.

[Median re-sternotomy for aortic valve re-replacement assisted by video-assisted thoracic surgery]

Cardiac reoperation via a median re-sternotomy is associated with a high risk of injury to cardiac structures and the great vessels, and may result in massive bleeding. We report a case of aortic valve re-replacement, and severe adhesion was suspected between the sternum and the left brachiocephalic vein by preoperative computed tomography (CT) scans. To avoid injury to the vein, the adhesive tissue was dissected under video-assisted thoracic surgery (VATS). Then median re-sternotomy was performed safely, and the aortic valve was replaced again. The patient's postoperative course was uneventful. Since sternal adhesions are checked and dissected visually, concomitant VATS might be a very useful option after previous cardiac surgery.

Electron Channeling X-ray Microanalysis for Cation Configuration in Irradiated Magnesium Aluminate Spinel

High angular resolution electron channeling x-ray spectroscopy (HARECXS) was examined as a practical tool to locate lattice-ions in spinel crystals. The orientation dependent intensity distribution of emitted x-rays obtained by HARECXS is so sensitive to lattice-ion configuration in the illuminated areas that the occupation probabilities on specific positions in the crystal lattice can be determined accurately through comparison with the theoretical rocking curves. HARECXS measurements have revealed partially disordered cation arrangement in MgO·nAl2O3 with n= 1.0 and 2.4. Most A13+ lattice-ions occupy the octahedral (VI) sites with 6-fold coordination, while Mg2+ lattice-ions reside on both the tetrahedral (IV) and the octahedral (VI) sites. The structural vacancies are enriched in the IV-sites. Further evacuation of cations from the IV-sites to the VI-sites is recognized in a disordering process induced by irradiation with 1 MeV Ne+ ions up to 8.9 dpa at 870 K.

Mechanisms of factor VIIa-catalyzed activation of factor VIII

BACKGROUND

Factor (F)VIIa, complexed with tissue factor (TF), is a primary trigger of blood coagulation, and has extremely restricted substrate specificity. The complex catalyzes limited proteolysis of FVIII, but these mechanisms are poorly understood.

OBJECTIVES

In the present study, we investigated the precise mechanisms of FVIIa/TF-catalyzed FVIII activation.

RESULTS

FVIII activity increased ~4-fold within 30 s in the presence of FVIIa/TF, and then decreased to initial levels within 20 min. FVIIa (0.1 nM), at concentrations present physiologically in plasma, activated FVIII in the presence of TF, and this activation was more rapid than that induced by thrombin. The heavy chain (HCh) of FVIII was proteolyzed at Arg(740) and Arg(372) more rapidly by FVIIa/TF than by thrombin, consistent with the enhanced activation of FVIII. Cleavage at Arg(336) was evident at ~1 min, whilst little cleavage of the light chain (LCh) was observed. Cleavage of the HCh by FVIIa/TF was governed by the presence of the LCh. FVIII bound to Glu-Gly-Arg-active-site-modified FVIIa (K(d), ~0.8 nM) with a higher affinity for the HCh than for the LCh (K(d), 5.9 and 18.9 nm). Binding to the A2 domain was particularly evident. Von Willebrand factor (VWF) modestly inhibited FVIIa/TF-catalyzed FVIII activation, in keeping with the concept that VWF could moderate FVIIa/TF-mediated reactions.

CONCLUSIONS

The results demonstrated that this activation mechanism was distinct from those mediated by thrombin, and indicated that FVIIa/TF functions through a 'priming' mechanism for the activation of FVIII in the initiation phase of coagulation.

Diabetic striatal disease: clinical presentation, neuroimaging, and pathology

BACKGROUND

Unilateral movement disorders and contralateral neuroimaging abnormalities of the striatum have been sporadically reported as a rare syndrome associated with diabetes mellitus. Despite characteristic imaging findings and clinical manifestations, the mechanism underlying this syndrome is still unclear.

METHODS

Six patients with this syndrome were studied clinically and subjected to MRI neuroimaging; one underwent biopsy of the striatum, and another underwent additional MR spectroscopy at 3.0T and FDG-PET.

RESULTS

Neuroimaging findings were characterized by a T1-hyperintense unilateral lesion restricted to the striatum, contralateral to the symptomatic limbs. The biopsied striatum contained patchy necrotic tissue, severe thickening of all layers of arterioles, and marked narrowing of vessel lumens. Hyaline degeneration of the arteriolar walls, extravasation of erythrocytes, and prominent capillary proliferation were also notable, together with lymphocytic infiltration and macrophage invasion. In one patient, PET examination revealed decreased accumulation of FDG in the lesion. The MR spectrum for the diseased striatum revealed a decrease in the NAA/Cr ratio (1.35), normal Cho/Cr ratio (1.22), and a peak for myoinositol, while the spectrum on the contralateral site revealed a decrease in the NAA/Cr ratio (1.48), increase in Cho/Cr (1.32), but no peak for myoinositol.

CONCLUSION

The constellation of signs and symptoms and neuroimaging characteristics in previous reports and the six additional cases described here with neuropathological data and findings of MR spectroscopy appears unique enough to be termed "diabetic striatopathy." This syndrome appears in poorly controlled diabetics due to obliterative vasculopathy with prominent vascular proliferation, vulnerability to which is restricted to the striatum.

Factor XI contributes to thrombus propagation on injured neointima of the rabbit iliac artery

BACKGROUND

Thrombus formation through the activation of tissue factor (TF) and factor (F) XI is a critical event in the onset of cardiovascular disease. TF expressed in atherosclerotic plaques and circulating blood is an important determinant of thrombogenicity that contributes to fibrin-rich thrombus formation after plaque disruption. However, the contribution of FXI to thrombus formation on disrupted plaques remains unclear.

METHODS

A mouse monoclonal antibody against FXI and activated FXI (FXIa) (XI-5108) was generated by immunization with activated human FXI. Prothrombin time (PT), activated partial thromboplastin time (APTT), bleeding time, and ex vivo platelet aggregation in rabbits were measured before and after an intravenous bolus injection of XI-5108. We investigated the role of FXI upon arterial thrombus growth in the rabbit iliac artery in the presence of repeated balloon injury.

RESULTS

The XI-5108 antibody reacted to the light chain of human and rabbit FXI/FXIa, and inhibited FXIa-initiated FXa and FXIa generation. Fibrin-rich thrombi developed on the injured neointima that was obviously immunopositive for glycoprotein IIb-IIIa, fibrin, TF, and FXI. Intravenous administration of XI-5108 (3.0 mg kg(-1)) remarkably reduced thrombus growth, and the APTT was significantly prolonged. However, PT, bleeding time and platelet aggregation were not affected.

CONCLUSIONS

These results indicate that plasma FXI plays a potent role in thrombus growth on the injured neointima. Inhibition of plasma FXI activity might help to reduce thrombus growth on ruptured plaques without prolonging bleeding time.

[Acute type A aortic dissection combined with surgical treatment with acute myocardial infarction]

Acute myocardial infarction, as a result of coronary malperfusion caused by acute type A aortic dissection, has been identified as one of significant factors relating to operative mortality. This complication could be diagnosed with a combination of electrocardiography and echocardiography in acute phase. However, the indication of coronary angiography and/or intervention has been controversial as it is time-consuming and renders additional stress to a critical patient requiring an emergency operation. We report a case of myocardial infarction successfully treated with percutaneous transluminal coronary angioplasty (PTCA) at first, after that, recognition of dissection of aorta necessitated subsequent surgical therapy. In this particular case, coronary intervention in advance proved to be mandatory.

Intracranial invasive aspergillosis originating in the sphenoid sinus: a successful treatment with high-dose itraconazole in three cases

We report three cases of intracranial aspergillosis originating in the sphenoid sinus in immunocompetent patients. The patients presented with an orbital apex syndrome in that a unilateral loss of vision and cranial nerve III palsy were seen in all cases and a contralateral involvement was also seen in one case. Despite the initial treatment with a conventional dose of itraconazole (ITCZ, 200 mg/day), the neurological deficits failed to improve and the granulomatous inflammation was not suppressed. Therefore, we treated with a combination of a high dose of ITCZ at 500-1000 mg/day (16-24 mg/kg/day) and amphotericin B (AMPH-B) at 0.5 mg/kg/day, in conjunction with a pulse dose of methylprednisolone at 1000 mg/day. Two cases responded favorably in that the ocular movements completely recovered, and their maximum serum concentrations of the hydroxy ITCZ were 7816 ng/ml and 5370 ng/ml. However, the other case worsened, despite ITCZ treatment at 16 mg/kg/day, and the serum concentration of the hydroxy ITCZ was 3863 ng/ml. The surgical decompression of the cavernous sinus via an extradural approach was performed, and the dose of ITCZ was increased to 24 mg/kg/day. The resulting serum concentration of the hydroxy ITCZ was 4753 ng/ml, and the outcome of this case has been favorable. These results suggest that a high blood level of the hydroxy ITCZ (more than 4500 ng/ml) is a prerequisite for the successful treatment of intracranial aspergillosis and that the combination treatment of ITCZ with AMPH-B would be preferred. The concomitant use of steroid and/or surgical decompression should be considered, if the invasiveness is not well-controlled in spite of intensive medical therapy.

[A case of hypertrophic pachymeningitis, resolved by antimicrobial therapy]

A 65-year-old woman with diabetes mellitus and chronic otitis media developed headache, fever, and hoarseness, all of which did not responded to the oral antibiotics. As stiff neck and lower cranial nerve palsies appeared, bacterial meningitis was suspected. Neurological examination revealed the right hearing disturbance, right recurrent laryngeal nerve palsy, left sternocleidomastoid muscle atrophy and bilateral tongue atrophy. The CSF examination revealed mild pleocytosis and elevated protein, but no bacterial organism was cultured from the CSF. CT scans showed bilateral mastoiditis, and the right mastoid process and a posterior part of the petrous bone were eroded, indicating the exposed bony structures to the posterior fossa. MRI scans demonstrated the thickening of the dura mater of the posterior fossa and the right cerebellar tentorium. This is a rare example of bacterial pachymeningitis of the posterior fossa, the clinical symptoms and MRI findings of which resolved solely by antimicrobial agents without corticosteroid.

Cold induces shifts of voltage dependence in mutant SCN4A, causing hypokalemic periodic paralysis

BACKGROUND

The authors reported a mutation, P1158S, of the human skeletal muscle sodium channel gene (SCN4A) in a family with cold-induced hypokalemic periodic paralysis (hypoKPP) and myotonia.

OBJECTIVE

To identify mechanisms of temperature dependency in this channelopathy.

METHODS

Using the amphotericin B perforated patch clamp method, sodium currents were recorded at 22 and 32 degrees C from the wild-type (WT) and P1158S mutant SCN4A expressed in tsA201 cells. Computer simulation was performed, incorporating the gating parameters of the P1158S mutant SCN4A.

RESULTS

P1158S mutant SCN4A exhibited hyperpolarizing shifts in voltage dependence of both activation and inactivation curves at a cold temperature and a slower rate of inactivation than the WT. Computer simulation reproduced the abnormal skeletal muscle electrical activities of both paralysis at a low potassium concentration in the cold and myotonia at a normal potassium concentration.

CONCLUSIONS

Both paralysis and myotonia are attributable to the biophysical properties of the SCN4A mutation associated with hypoKPP. This is the first report of an SCN4A mutation that exhibits temperature-dependent shifts of voltage dependence in sodium channel gating.

[A case report of Ebstein's anomaly treated with Hetzer's procedure]

A 27-year-old male who had been diagnosed with Ebstein's anomaly was admitted with uncontrollable congestive heart failure. The echocardiogram revealed severe tricuspid valve incompetence and the electrocardiogram showed atrial fibrillation. He underwent Hetzer's repair procedure for tricuspid valve incompetence and Minzioni's right atrial isolation technique to restore sinus rhythm. His congestive heart failure quickly disappeared and sinus rhythm was restored after operation. He was discharged 3 weeks postoperatively and remains well 22 months after his operation. Hetzer's technique for tricuspid valve repair in Ebstein's anomaly restructures the valve mechanism at the level of the true tricuspid anulus by using the most mobile leaflet for valve closure without plication of the atrialized chamber. We conclude that Hetzer's procedure is an effective operation for Ebstein's anomaly.

Surgical treatment of abdominal aortic aneurysms located close to the visceral arteries: report of three cases

The standard surgical treatment for abdominal aortic aneurysms (AAA) is in situ replacement of the infrarenal aorta, which is associated with a low mortality rate. On the other hand, thoracoabdominal aortic aneurysms (TAA) remain a formidable challenge and the complications that can occur may be severe including neurologic dysfunction and renal failure. We report herein three cases of patients with AAA located very close to the visceral arteries, for which in situ replacement of the infrarenal aorta was not feasible due to severe inflammation and adhesion. Therefore, aortic stump closure and in situ bypass grafting was performed to avoid reconstruction of the visceral arteries. No major complications or operation-related deaths occurred. Thus, while in situ replacement is usually recommended over bypass grafting for patients whose aneurysms are located very close to the visceral arteries, aortic stump closure and in situ bypass grafting should be considered as a more effective surgical option.

Penetrating atherosclerotic ulcer at the proximal aorta complicated with cardiac tamponade and aortic valve regurgitation

A 56-year-old man had a penetrating atherosclerotic ulcer originating in the proximal ascending aorta, which is an unusual case of penetrating aortic ulcer complicated with the aortic valve regurgitation and cardiac tamponade. This hemodynamically unstable patient was successfully treated by conservative management to control his blood pressure and was also monitored closely with follow-up imaging studies.

Antibody fragments as inhibitors of Japanese radish acid phosphatase

VH (heavy-chain variable region) and VL (light-chain variable region) genes were amplified by PCR from hybridomas producing MAb-11 and MAb-18 which inhibited Japanese radish acid phosphatase. Nucleotide sequencing of the V genes demonstrates that the MAbs contained similar VH and identical VL domains. Initially, the VH and VL genes were expressed in Escherichia coli as single-chain Fv (ScFv) fragments. Fragments ScFv-11 and ScFv-18, named for MAb-11 and MAb-18, respectively, inhibited the enzyme activity to the same extent as the intact MAbs. Both of the antibody fragments widely cross-reacted with other phosphatases, including some phosphomonoesterases and phosphodiesterases from different sources. ScFv-18 also inhibited acid phosphatase from a different origin, but stimulated the activity of alkaline phosphatase from calf intestine. The PCR-amplified VH and VL genes were subsequently expressed separately in Escherichia coli as fusion products with glutathione S-transferase. The fusion proteins had little effect on Japanese radish acid phosphatase. Furthermore, a large number of recombinant ScFv fragments specific to the acid phosphatase were generated by using a bacteriophage expression system and a mouse ScFv gene library. These ScFv fragments had a range of effects on the enzyme activity, including inhibition, stimulation, and none. Among them, an ScFv fragment, designated ScFv-G7, inhibited more strongly than ScFv-11 and ScFv-18.

Simultaneous measurements of lactate and blood flow during hypoxia and recovery from hypoxia in a localized region in the brain of the anesthetized rabbit

We observed simultaneous changes in lactate level and regional blood flow (rBF) in the brain of the anesthetized rabbit by using localized proton magnetic resonance spectroscopy (1H MRS) and laser Doppler flowmetry. The volume of interest of 0.5 ml for 1H MRS contained mostly thalamic nuclei. During hypoxia peak area for lactate increased up to 57% of that from N-Acetylaspartate. While the rBF increased during hypoxia up to 260% of the control, oxygen delivery (rBF x arterial oxygen content) decreased. In the normoxic recovery period following hypoxia, the rBF recovered slowly and a consequent overshoot of oxygen delivery was observed. The multiple and stepwise linear regression analyses revealed that the averaged decrease in oxygen delivery during hypoxia was the most significant independent variable for the increase in lactate during hypoxia (correlation coefficient; r2 = 0.68) and also that the increase in lactate during hypoxia was the most significant independent variable for the time for half-recovery of rBF (r2 = 0.75). These results suggest that the increase in lactate during hypoxia is due to the deficiency of oxygen delivery and that the increase in lactate during hypoxia prolongs the period of enhancement of rBF during recovery from hypoxia.

Iliac artery dissection originating in a true aneurysm. A case report

The spontaneous dissection of a peripheral artery not involving the aorta is rare and usually does not arise from a true aneurysm. This is the first report of a spontaneous external iliac artery dissection originating in a true aneurysm.

[A case report of huge bronchogenic cyst originated in the atrial septum]

Bronchogenic cysts of the heart are extremely rare neoplasma comprising only 1.3% of all the primary cardiac and pericardial tumors. We experienced a case of bronchogenic cyst originated in the interatrial septum that caused the marked swelling of the septum. An asymptomatic woman of 43 years of age was evaluated because of cardiac enlargement on the chest X-ray film. The examinations including cardiac catheterization indicated a left atrial tumor broadly based on the atrial septum. Surgical removal was attempted, and the tumor was revealed to be a cyst involving the whole atrial septum. The histological diagnosis was bronchogenic cyst. The surgery included resection of the cyst together with the septum that was reconstructed with Dacron patch. Postoperative course was smooth, and the patient has returned to normal daily life without any sign of recurrence for two years.

[A case of aortic dissection associated with congenital bicuspid aortic valve]

It is known that bicuspid aortic valve with dilatation of the ascending aorta is one of risk factors of the aortic dissection. A case of acute aortic dissection (DeBakey type-II) associated with bicuspid aortic valve who underwent successfully operation 8 hours after onset is reported. This patient went into cardiogenic shock because of cardiac tamponade and aortic valve regurgitation immediately after onset. Aortic valve and the ascending aorta were replaced using composite graft (#23 SJM prosthetic aortic valve and 26 mm woven Dacron vascular graft) combined with coronary artery reconstruction by Cabrol's technique. Aortic valve showed bicuspid and histological examination revealed cystic medionecrosis and loss of elastic fiber. Postoperative course was uneventful and this patients is doing well 3 years after the operation.

Repair of a ruptured aortic arch aneurysm complicated by postoperative paraplegia: report of a case

We report herein the rare case of a 79-year-old man who suffered permanent paraplegia after undergoing an otherwise successful total arch replacement for a ruptured aortic arch aneurysm. During cardiopulmonary bypass, perfusion to the distal aorta was maintained from the femoral artery, and postoperative aortography showed intact tributaries from the aorta including the intercostal arteries. Postoperative paraplegia is an extremely rare complication of operations on the aortic arch; however, we speculate that the paraplegia in this patient could be attributed either to a steal phenomenon involving the radicular artery, or to the anatomical particularity of the spinal cord artery described by Cole and Gutelius as the "segmental system".

[Factors affecting the occurrence of anastomotic leakage after graft replacement of type A aortic dissection]

Fifty-seven patients of type A aortic dissection were underwent operations from Jan. 1985 to Nov. 1994. The number of patients who underwent graft replacement of the aorta and received aortogram after the operation was twenty-nine. To investigate factors affecting the occurrence of anastomotic leakage after graft replacement of the aorta, the aortograms of the 29 patients were examined retrospectively. The aortograms revealed leakage at the distal anastomotic site on 11 of the 29 patients. Eight factors: the kind of graft, Marfan's syndrome, the use of felt at the anastomotic site, the clamping method, distal anastomotic site, acute or chronic, the state of the aortic wall at the anastomotic site and the blood pressure control after operation, were examined relating to the occurrence of anastomotic leakage. The results showed 3 factors; acute or chronic, the state of the aortic wall and the blood pressure control, affected the occurrence of anastomotic leakage. In short, the anastomotic leakage easily occurred in patients who underwent in the acute stage and whose blood pressure was uncontrolled after the operation. Therefore, strict control of the blood pressure after the operation is the most effective for preventing anastomotic leakage.

The effect of body position on a free-floating ball thrombus as observed by transesophageal echocardiography

Two cases of free-floating left atrial ball thrombi (FLABT) in association with mitral stenosis were observed by transesophageal echocardiography (TEE). Our report describes the relation between body position and thrombi kinetics. Both cases demonstrated similar kinetics. In the supine and right lateral decubitus positions, the thrombi recoiled from and sometimes became entrapped within the mitral valve. In the sitting and left lateral decubitus positions, the thrombi appeared to be nearly fixed and did not contact with the mitral valve. Our results indicate that the latter two positions prevent thrombi disintegration and incarceration into the mitral valve. Finally, TEE is an extremely useful tool for assessing the safest position for individuals with FLABT.

Myocardial microdialysis of salicylic acid to detect hydroxyl radical generation during ischemia

We examined in vivo monitoring of hydroxyl radical (.OH) generation during myocardial ischemia for 30 min by occluding the left anterior descending (LAD) in dog heart using a microdialysis technique. The hydroxyl radical reacts with salicylate and generates 2,3- and 2,5-dihydroxybenzoic acids (DHBA) which can be measured electrochemically in picomole quantity by a high pressure liquid chromatography-electrochemical (HPLC-EC) procedure. When the premature ventricular contraction (PVC) occurred at almost 25 sec intervals, marked elevation of the levels of 2,3- and 2,5-DHBA was observed in the heart dialysate of 30-min ischemia. This study demonstrated the generation of .OH in the canine heart subjected to 30-min ischemic insult.

Biocompatibility of a heparin-bonded membrane oxygenator (Carmeda MAXIMA) during the first 90 minutes of cardiopulmonary bypass: clinical comparison with the conventional system

We clinically compared a heparin-bonded Carmeda MAXIMA membrane oxygenator to a nonheparin-bonded MAXIMA in 20 patients undergoing coronary artery bypass grafting or valve replacement. Reductions of fibrinogen, factor XII, and high molecular weight kininogen were greater in the MAXIMA group. Serum C3a and free hemoglobin were lower in the Carmeda group. The level of C4a, though remarkably lower than that of C3a, was higher in the Carmeda group then in the MAXIMA group. Both oxygenators performed well in terms of blood gas exchange. We conclude that the heparin-bonded Carmeda oxygenator offers superior biocompatibility during cardiopulmonary bypass.

[Effect of pirenzepine on gastric mucosal blood flow in patients after cardiac surgery]

Effect of pirenzepine on gastric mucosal blood flow (GMBF) in adult patients after coronary artery bypass grafting and mitral and aortic valve replacement was evaluated by using endoscopic laser-Doppler velocimetry. Heart rate, blood pressure and cardiac output increased temporarily after intravenous administration of pirenzepine 20 mg. GMBF also increased with these hemodynamic changes. However, GMBF remained significantly higher even after the decrease of cardiac output. Therefore, the increase in GMBF, which might be due in part to increase in cardiac output, could be explained by pirenzepine's own effect on gastric mucosa. Since the GMBF is one of the most important gastric mucosal defensive factors, pirenzepine may be useful in preventing acute gastric mucosal lesions in patients with low cardiac output.

[Two cases of aortoesophageal fistula due to ruptured thoracic aortic aneurysm]

Aortoesophageal fistula due to ruptured thoracic aortic aneurysm is uncommon, and exhibits extremely high mortality. We experienced two cases of such lesion. The first case showed aneurysm in the aortic arch closed with Dacron patch but leaving the esophageal defect. The patient died of an infection of the patch graft after oral feeding. The second case was demonstrated infected aneurysm of the descending aorta. The patient was rescued by primary operation, replacement of the aorta by an artificial graft and resection of the esophagus, and the secondary operation, reconstruction of the esophagus. We recommend resection of aneurysm and the esophagus as well in the aspect of lower post-operative infection in the graft and of the better prognosis of the lesion.

[Surgical treatment of endocardial cushion defect in 3 elderly patients]

We performed surgical treatment for partial endocardial cushion defect in 3 patients over fifty year old. Case 1 was a 55-year-old-male with TR of grade II. Case 2 was a 59-year-old-female with TR and MR, and was repaired mitral cleft by a mattress suture. She needed infusion of dopamine (over 5 micrograms/kg/min) for 6 days and therapy of mediastinitis postoperatively. Case 3 was 56-year-old-male without atrioventricular valve regurgitation. Preoperative left ventricular volume was small in all patients, therefore perioperative circulatory control, mainly water balance, and respiratory control were importance. All patients survived, and both decreasing of CTR and improvement of NYHA classification were recognized in all three patients. In conclusion the operation for ECD in even elder patients was effective, but intensive care needed perioperatively.

[A case of small-sized lung adenocarcinoma, 4 mm in diameter, detected by CT]

A 67-year-old woman presented to our hospital because of an abnormal shadow on her chest X-ray film. The film showed a well-circumscribed nodule, 15 mm in diameter, in her left lower lung field. Compared with her prior film of 1.5 years ago, the size of the nodule had not changed, suggesting the possibility of a benign lung tumor. Chest CT with 10 mm-thick collimation demonstrated another small round opacity near the nodule in the left lower lobe; this small opacity was not detectable on plain chest films. For further analysis of the small opacity, high resolution CT was carried out. High resolution CT with 1.5 mm collimation showed a 4 mm nodule with an ill-defined margin and relatively low internal density, and probable involvement of a peripheral branch of the pulmonary vein. These features suggested the possibility of malignant characteristics of this small opacity. The patient underwent thoracotomy and pathologic examination revealed that the large well-circumscribed nodule was a hamartoma and the small nodule was a papillary adenocarcinoma lesion. High resolution CT is prerequisite to diagnosing the characteristics of small pulmonary nodules.

[Effect of maternally derived antibody levels on antibody responses to canine parvovirus, canine distemper virus and infectious canine hepatitis virus after vaccinations in beagle puppies]

Antibody titers against canine parvovirus (CPV), canine distemper virus (CDV) and infectious canine hepatitis virus (ICHV) in serum were measured in 6 beagle dams and their 38 puppies bred in our colony, in order to clarify the effects of maternally derived antibodies to antibody responses against the viruses after vaccinations in puppies. Correlation coefficient on antibody titers between puppies and dams were CPV: r = 0. 7935, CDV: r = 0.8194 and ICHV: r = 0.8105. Mean maternal antibody positive rates in 7-day-old puppies from their dams were CPV: 67%, CDV: 46% and ICHV: 45%. Mean half-lives of the maternal antibodies in puppies were estimated to be CPV: 13.5 days, CDV: 15.1 days and ICHV: 15.4 days. The antibody response against CPV vaccination in puppies was mainly observed in dogs being titers of less 1:5 and positivity was 39% (15/38 puppies) after 1st vaccination at 42 days after birth, and 82% (31/38 puppies) after 2nd vaccination at 70 days. That against CDV vaccination (at 56 days after birth) was seen highly in dogs being titers of less 1:10 and positivity was 53% (20/38). Also that against ICHV vaccination (at 56 days after birth) was seen frequently in dogs being titers of less 20 holds and the rate was 87% (33/38). From these results, it was estimated that the age when high antibody response against each vaccination could be expected in puppies might be CPV: between 40 and 69 days, CDV: between 32 and 92 days and ICHV: between 31 and 52 days, respectively.

[Cerebral hemodynamics in multiple cerebral infarction with or without dementia]

Cerebral blood flow and metabolism in 25 patients with multiple cerebral infarcts (14 with dementia) and 5 healthy age-matched controls were measured to investigate the difference in cerebral blood low (CBF) and cerebral oxygen consumption (CMRO2) between patients with dementia and patients without dementia. None of the patients had any lesions in the cortex, but all had multiple lesions in the basal ganglionic region, and in the white matter, according to CT images. CBF, CMRO2 and oxygen extraction fraction were measured by positron emission tomography (PET) using the 15O2, C15O2 steady state inhalational technique. In patients with multiple cerebral infarcts the absolute values of CBF and CMRO2 were decreased significantly from normal control values, and there was no significant difference in the absolute values of CBF and CMRO2 between patients with dementia and patients without dementia. In most patients with dementia, relative values (regional value/mean cortical value) of CBF and CMRO2 decreased in the frontal and the parietal cortex. Four patients had repeated PET studies. In two of them, decrease in CMRO2 was preceded by decrease in CBF. These results suggest that dysfunction of frontal cortex and parietal cortex, and chronic ischemia might be related to the occurrence of dementia in patients with multiple cerebral infarcts, which were in the basal ganglia and the white matter.

[Cerebral blood flow and oxygen metabolism in patients with Parkinson's disease]

The distribution of cerebral blood flow and metabolism is related to neuronal activity. Cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and oxygen extraction fraction (OEF) in ten patients with Parkinson's disease and five age-matched normal control subjects were measured with positron emission tomography (PET) using 15O2, C15O2 steady state inhalational technique to investigate functional changes of the cortex and the basal ganglia in Parkinson's disease. All patients had no history of cerebrovascular disease and CT scan showed no abnormal findings except for moderate cerebral atrophy in only one patient. When the level of clinical disability was related on the scale of Hoehn and Yahr, one patient was stage I, four were stage II, four were stage III, and one was stage IV. Psychic symptoms which include hallucination, depression, and dementia were recognized in four patients. One of these four patients was mildly demented. Four patients were newly diagnosed and had never been treated with antiparkinsonian medication before. Before the patients had their PET study their antiparkinsonian medication was discontinued for more than three days. But in two patients PET study was performed without discontinuity of antiparkinsonian medication. The values for regional CBF and regional CMRO2 were lower in the patients than in the normal control subjects, especially in the frontal cortex there was a significant decrease of CBF and CMRO2. There was no discrepancy between CBF and CMRO2 both in the patients and the normal control. CBF and CMRO2 in the cortex and the basal ganglia were not correlated with the severity of tremor, bradykinesia, and rigidity.(ABSTRACT TRUNCATED AT 250 WORDS)