Unusual changes detected by iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid myocardial single photon emission computed tomography in the process of acute myocardial infarction: a case report

Iodine-123 15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid myocardial single photon emission computed tomography(iodine-123 BMIPP myocardial SPECT) is useful for the diagnosis and evaluation of ischemic myocardial disease or cardiomyopathy. Changes in fatty acid metabolism in the post-myocardial ischemic state were evaluated using iodine-123 BMIPP myocardial SPECT. A 77-year-old woman was hospitalized for treatment of acute myocardial infarction. Emergency coronary angiography showed severe stenosis with delayed filling of contrast medium in the middle portion of the left anterior descending artery, so primary percutaneous transluminal coronary angioplasty was performed successfully. On the second day, iodine-123 BMIPP uptake was decreased slightly on the early imaging in the apico-anterior region, and increased slightly on the delayed imaging. On the seventh day, iodine-123 BMIPP uptake was decreased moderately or markedly in the apico-anterior region on the early imaging, and decreased markedly on the delayed imaging. Iodine-123 BMIPP myocardial SPECT subsequently became almost normalized. These unusual dynamic changes In iodine-123 BMIPP myocardial SPECT imaging may reflect metabolic changes of fatty acids in the ischemic state, the size of the triacylglycerol pool, and the degree of turnover in the triacylglycerol pool.     

Can serum carnitine levels distinguish hypertrophic cardiomyopathy from hypertensive hearts?

Although echocardiography is a useful diagnostic tool in hypertrophic cardiomyopathy (HCM), it is sometimes difficult to differentiate it from hypertensive heart disease (HHD): some patients with HCM show symmetrical hypertrophy, whereas patients with HHD sometimes show asymmetrical septal hypertrophy. We used a radioiodinated long-chain fatty acid tracer to visualize the altered myocardial fatty acid metabolism of HCM and HHD. Carnitine is the essential substance for the beta-oxidation of long-chain fatty acids. We recently reported that serum free carnitine levels in HCM were elevated and that they were significantly correlated with the severity of myocardial fatty acid metabolic disorder. Therefore, we investigated serum carnitine levels in patients with HCM and HHD, which can contribute to the differentiation of each other. We studied 56 patients with HCM and 20 patients with essential hypertension. Serum free carnitine levels were significantly higher in patients with HCM than those with HHD (HCM 52.5+/-9.5 nmol/mL, HHD 46.6+/-6.4 nmol/mL, P<0.01), but they showed no statistical difference between patients with HHD and normal subjects. Serum acylcarnitine levels were significantly lower in patients with HCM than those with HHD (HCM 10.1+/-4.0 nmol/mL, HHD 14.5+/-4.9 nmol/mL, P<0.0005), although they did not differ between patients with HHD and normal subjects. Scintigraphic analyses with a long-chain fatty acid analog revealed that myocardial tracer uptake was much reduced in patients with HCM compared with that in patients with HHD (quantitative analysis: HCM 2.11+/-0.12, HHD 2.22+/-0.17, P<0.05; semiquantitative analysis: HCM 13.6+/-6.3, HHD 2.0+/-1.5, P<0.0001). In conclusion, the differences in serum carnitine levels between HCM and HHD reflect altered myocardial fatty acid metabolic impairment, and the levels can help to distinguish these 2 diseases.     

Two cases of long lasting bacteremia due to Mycobacterium avium complex despite new macrolides-containing regimens in patients with acquired immunodeficiency syndrome

The prognosis of Mycobacterium avium complex (MAC) infection has been improved by new macrolides-containing regimens and the use of highly active antiretroviral therapy (HAART) in the treatment of acquired immunodeficiency syndrome (AIDS). We report on two AIDS cases with long lasting bacteremia due to MAC under this regimen. Both patients experienced problems due to side effects from the anti-MAC regimen and from an immune-reconstitution syndrome related to HAART. MAC infection persisted despite treatment, however, no anti-MAC drug-resistant isolates emerged throughout the clinical course in either case. These cases demonstrate that therapy for disseminated MAC infection is sometimes difficult even with HAART and macrolides-containing regimens.     

Pro-oxidative effect of alpha-tocopherol in the oxidation of LDL isolated from co-antioxidant-depleted non-diabetic hemodialysis patients

The association between the antioxidants in LDL and the oxidizability of LDL assessed by the oxidation lag time during copper ion-catalyzed oxidation was investigated in 69 non-diabetic hemodialysis patients and 23 healthy volunteers. The concentrations of co-antioxidants, including ubiquinol-10, lycopene and beta-carotene, in LDL were significantly lower in the hemodialysis patients than in the healthy volunteers, while there was no difference in the alpha-tocopherol concentration between the groups. The lag time showed a significantly positive correlation with the alpha-tocopherol level (r = 0.62, P < 0.01) in the healthy subjects, but a significantly negative correlation (r = -0.38, P < 0.05) in the hemodialysis patients. Furthermore, in vitro incubation of LDL with alpha-tocopherol prolonged the lag time in the healthy subjects, but shortened it in the hemodialysis patients. These results suggested that the alpha-tocopherol might exert the pro-oxidative effect in co-antioxidant-depleted LDL that was isolated from the hemodialysis patients. Despite such co-antioxidant depletion and the pro-oxidative effect of alpha-tocopherol, the lag time in the hemodialysis patients was not statistically different from that in the healthy volunteers. This might have been because the polyunsaturated fatty acids concentration, another determinant of the lag time, in LDL was less in the hemodialysis patients than in the healthy controls.     

Impairment of lymphopoiesis and myelopoiesis in mice reconstituted with bone marrow-hematopoietic progenitor cells expressing SDF-1-intrakine

Both SDF-1 and CXCR4 disruption are lethal to mice at the embryonic stage and cause abnormalities in B lymphopoiesis, myelopoiesis, cardiogenesis, vasculogenesis, and cerebellar development. To investigate the role of SDF-1 and CXCR4 in hematopoiesis during the adult stage, mice reconstituted with bone marrow-derived hematopoietic progenitor cells transduced with either the SDF-1 or a genetically modified SDF-1-intrakine gene using a retroviral expression vector were analyzed. Flow cytometric (FCM) analysis showed a dramatic reduction of CXCR4 expression on the cells of intrakine-transduced mice, whereas CCR7 and CCR1 expression was unchanged or marginally decreased on splenocytes. Migration of splenocytes and bone marrow cells to SDF-1 was markedly suppressed in intrakine-transduced mice. FCM analysis of bone marrow cells of intrakine-transduced mice exhibited decreased numbers of pro-B (B220(+) CD43(+)), pre-B (B220(+) CD43(-)), and immature B (B220(+) IgM(+)) cells and a decreased number of granulocytes/myeloid (Gr1(+) CD11b(+)) cells. Impaired B lymphopoiesis and myelopoiesis in intrakine-transduced mice were confirmed by an in vitro colony-forming assay of bone marrow cells. In contrast, B lymphopoiesis and myelopoiesis were enhanced in SDF-1-transduced mice. Interestingly, T-cell maturation in the thymus was impaired both in intrakine- and SDF-1-transduced mice, suggesting that SDF-1 and CXCR4 play an important role in T lymphopoiesis as well as in B lymphopoiesis and myelopoiesis in adults. These results demonstrate an essential role of CXCR4 and its ligand SDF-1 in adult hematopoiesis, and they indicate the intrakine method as a powerful tool for functional analysis of chemokines/chemokine receptors in vivo and as a potential therapeutic approach for acquired immunodeficiency syndrome.     

Pharmacological and electrophysiological characterization of junctional rhythm during radiofrequency catheter ablation of the atrioventricular node: possible involvement of neurotransmitters from autonomic nervous system.

Catheter ablation of the atrioventricular node (AVN) with radiofrequency current is closely associated with the short-term onset of a junctional rhythm. The origin of this rhythm was analyzed in Beagle dogs which were anesthetized with pentobarbital sodium. Atrioventricular (AV) conduction block was induced first using a standard catheter ablation technique for the AVN, so that the sinus automaticity could not override the junctional ectopy during the following energy delivery. The ablation catheter was kept in the initial position and the delivery of radiofrequency energy was repeated. The pattern of ECG changes suggests that the dominant pacemaker may shift from the distal portion of the AV junctional area to the proximal portion during the energy delivery. This enhanced junctional automaticity was suppressed by the beta-blocker esmolol, but was not affected by M-antagonist atropine. Moreover, the beta-agonist isoproterenol did not induce the same type of junctional tachycardia, but the pacemaker shift was induced by the increased sympathetic tone after transient asystole by ventricular overdrive pacing or acetylcholine administration. These results suggest that proximal portion of the AV junctional area has extremely slow pacemaker activity, but responds to locally released norepinephrine with an abrupt rise and fall in rate, resulting in a typical pattern of junctional tachycardia during the ablation of the AVN.     

Acute production of vascular superoxide by angiotensin II but not by catecholamines

OBJECTIVE: To determine whether vascular superoxide is rapidly released by angiotensin II and is involved in vascular contraction. DESIGN: The effect of superoxide dismutase (SOD) on angiotensin II induced elevation of mean arterial blood pressure was measured. Subsequently, acute production of vascular superoxide by angiotensin II and its effect on isometric tension were measured in rat aortic rings. The effects of catecholamines were concomitantly measured. METHODS AND RESULTS: The acute pressor effects of angiotensin II were significantly reduced when rats were pretreated intravenously with SOD. When angiotensin II was added on aortic segments in the presence of Cypridina luciferin analog, immediate elevations of chemiluminescence were observed which were inhibited by SOD. Furthermore, angiotensin II-induced elevations of isometric tension in aortic rings were significantly reduced by SOD. The effects of epinephrine and norepinephrine were concomitantly measured and were not significant CONCLUSIONS: The acute superoxide producing effect is likely to be specific to angiotensin II, because such a significant modification of the effects was not observed for catecholamines. Our results suggest that angiotensin II causes acute vascular superoxide production, which may be involved in the acute pressor effects.     

Comparison of the newly developed MB redox system with mycobacteria growth indicator tube (MGIT) and 2% Ogawa egg media for recovery of mycobacteria in clinical specimens

The rate of recovery and the mean time to detection of mycobacteria in clinical specimens were determined in a newly-developed MB Redox system based on liquid medium, and the results were compared with those of MGIT and 2% Ogawa egg media. From 587 sputum specimens processed, totally 203 mycobacterial isolates were detected, of which 177 (87.2%) with MB Redox, 185 (91.1%) with MGIT and 133 (65.6%) with 2% Ogawa medium. The difference in the percentages of positive cultures between either of the two liquid media and 2% Ogawa medium was significant (p < 0.0001). The mean time to detection of the Mycobacterium tuberculosis complex was 17.5 days with MB Redox, 18.7 days with MGIT, and 26.2 days with 2% Ogawa medium. The contamination rates were 1.5, 1.7, and 4.1% for MB Redox, MGIT, and 2% Ogawa medium, respectively. In conclusion, both MB Redox and MGIT systems, based on liquid medium, are more efficient than 2% Ogawa medium for the recovery of mycobacteria in clinical specimens.     

Effectiveness of an antiplatelet agent for coronary artery ectasia associated with silent myocardial ischemia

A 74-year-old Japanese male was referred to our hospital because of an abnormal electrocardiogram. The electrocardiogram revealed tall P waves in leads II, III, and aV(F). Echocardiography disclosed hypokinesis extending from the anteroseptal region to the apex. Iodine-123 15-(p-iodophenyl)-3-(R,S)-methylpentadecanoic acid (123-BMIPP) scintigraphy revealed reduced uptake from the anteroseptal region to the apex. Coronary arteriography demonstrated diffuse dilatation of the right and left coronary arteries without organic stenosis, and left ventriculography showed hypokinesis at the same area. Furthermore, the coronary flow reserve in the left anterior descending artery was decreased. He was treated with an antiplatelet agent. Ten months later, the left ventriculography, 123I-BMIPP scintigraphy findings and coronary flow reserve were normalized. These findings demonstrate that antiplatelet therapy may be useful in the preservation of left ventricular function in patients with coronary artery ectasia.     

Adrenal pheochromocytoma with multiple neurofibromatosis on the trunk

We report a case of adrenal pheochromocytoma in a patient with neurofibromatosis type 1 (NF1). A 65-year-old female patient was admitted to our hospital for examination of a right adrenal mass. The adrenal tumor was incidentally discovered by abdominal computed tomography during examination for hypertension in another hospital. She had large multiple neurofibromatous lesions and café-au-lait spots on the trunk. We thought that it was difficult to make a skin incision on normal skin. Serum and urinary catecholamines were markedly increased. Magnetic resonance imaging revealed a solid round tumor 3 cm in diameter, located in the right adrenal gland. Laparoscopic right adrenalectomy was performed. Serum and urinary catecholamines returned to the normal range on post-operative day 10. Laparoscopic surgery may be a good option for NF1 patients with pheochromocytoma, especially those who had multiple neurofibromatosis on the trunk.