The pharmacokinetics and safety profiles of belimumab after single subcutaneous and intravenous doses in healthy Japanese volunteers.

WHAT IS KNOWN AND OBJECTIVES: Belimumab is a recombinant human monoclonal antibody that binds and antagonizes the biological activity of soluble B-lymphocyte stimulator (BLyS) protein. BLyS appears to play a role in the pathogenesis of systemic lupus erythematosus, and the biological profile of belimumab suggests that it may have a therapeutic benefit in the treatment for the disease. In this healthy Japanese subjects study, we investigated the pharmacokinetics and safety of a single subcutaneous and intravenous injection of belimumab administered as a 200 mg/mL liquid formulation. METHODS: This was an open-label, randomized, parallel-group, single-dose study in healthy Japanese subjects. Each subject received a single intravenous infusion or a subcutaneous injection of 200 mg belimumab. The pharmacokinetic parameters and safety parameters including local tolerance (injection site), biomarkers, immunogenicity and adverse events were evaluated up to 70 days post-dosing. RESULTS: After a single intravenous or a subcutaneous administration of 200 mg belimumab, all 16 subjects completed the study. There were no serious adverse events or adverse events related to injection site reactions. All seven adverse events were considered mild or moderate in intensity and deemed unrelated to belimumab except for cellulitis following intravenous administration. The bioavailability of the single subcutaneous dose of 200 mg belimumab in the subjects was estimated to be 77·5%. Time to the maximum serum concentration after subcutaneous injection was 6·5 days (median). The geometric mean terminal half-life was comparable between the two administration routes (17·7 days intravenous and 15·9 days subcutaneous). Serum immunoglobulin G level decreased slightly after each treatment. No subjects were found to produce antibelimumab antibodies. WHAT IS NEW AND CONCLUSIONS: A favourable absolute bioavailability in healthy Japanese subjects was seen following a subcutaneous injection of 200 mg belimumab. Considering the intersubject variability, exposures were consistent with those previously observed in healthy non-Japanese subjects. Safety and biomarker data were also consistent with previous non-Japanese clinical studies.

Impact of severe coronary disease associated or not associated with diabetes mellitus on outcome of interventional treatment using stents: results from HERZ (Heart Research Group of Kanazawa) analyses.

Percutaneous coronary intervention (PCI) using a drug-eluting stent (DES) leads to less re-stenosis than PCI using a bare metal stent (BMS), however there is still controversy whether use of a DES for severe coronary disease leads to an acceptable outcome in patients with diabetes mellitus (DM). In this study 8159 lesions were treated in 6739 patients (mean age 68.9 years) with coronary artery disease. Use of a DES significantly decreased the re-stenosis rate compared with BMS in both DM (9.6% versus 21.3%) and non-DM (9.5% versus 17.1%) patients. The re-stenosis rate was significantly higher in DM than in non-DM patients in the BMS group but not in the DES group. There was no statistically significant difference in event-free survival after stenting of patients with left main coronary artery (LMCA) disease between the BMS and DES groups. It was concluded that, compared with BMS, DES reduced re-stenosis in patients with DM, however, we advise careful treatment after using DES for severe coronary disease, including LMCA lesions, in patients with DM.

Exercise-induced systolic dysfunction in patients with non-obstructive hypertrophic cardiomyopathy and mutations in the cardiac troponin genes.

OBJECTIVES: The aim of this study was to investigate left ventricular (LV) function reserve in hypertrophic cardiomyopathy (HCM) patients with and without cardiac troponin gene mutations before transition to the dilated phase. METHODS: LV ejection fraction (EF) was continuously evaluated in 52 patients with non-obstructive HCM during supine ergometer exercise using radionuclide ventricular function monitoring with a cadmium telluride detector (VEST). On the basis of genetic analysis, patients were divided into two groups: 10 with cardiac troponin gene mutations (group A) and 42 without these gene mutations (group B). RESULTS: Exercise duration, peak exercise load, and heart rate during exercise did not differ between the two groups. The differences from baseline to peak exercise ofthe LV end-diastolic volume decreased similarly in the twogroups. In contrast, the difference of the LV end-systolicvolume in group A increased significantly compared withgroup B (17.7% (SD 12.7%) vs 3.4% (SD 13.2%);p=0.0031). Consequently, the difference of LVEF ingroup A decreased significantly in contrast with group B(-14.1% (SD 11.1%) vs -1.2% (SD 11.7%); p=0.0025).Additionally, the changes in LVEF and stroke volumedecreased significantly more in group A than in group B(-22.2% (SD 18.6%) vs -1.1% (SD 17.8%); p=0.0017and -12.9% (SD 21.7%) vs 12.3% (SD 24.4%);p=0.0042, respectively). CONCLUSIONS: These results suggest that HCM patientswith cardiac troponin gene mutations may displayexercise-induced LV systolic dysfunction more frequentlythan HCM patients without this abnormality

Phenotypic differences between electrocardiographic and echocardiographic determination of hypertrophic cardiomyopathy in genetically affected subjects.

OBJECTIVES: In the molecular era, two types of phenotypic differences are recognized between electrocardiography (ECG) and echocardiography in hypertrophic cardiomyopathy (HCM); ECG abnormalities in carriers without left ventricular hypertrophy (LVH), and normal ECG patterns in carriers with LVH. The goal of this study was to evaluate the diagnostic value of ECG for detecting carriers without LVH, and also to assess normal ECG patterns in carriers with LVH from the genetic standpoint of HCM. SETTING: A matched case-control study in a university hospital and general hospitals in Japan. PATIENTS AND DESIGN: ECG and echocardiographic findings were analysed in 173 genotyped subjects (107 genetically affected, 66 unaffected) from families with disease-causing mutations in four genes. RESULTS: ECG abnormalities were found in 18 (54.5%) of 33 nonhypertrophic carriers, but only nine (13.6%) of 66 noncarriers (P < 0.001). For detecting nonhypertrophic carriers, ST-T abnormalities showed the highest accuracy amongst the three major ECG criteria. In contrast, normal ECG patterns were found in eight (10.8%) of 74 carriers with LVH. The sensitivity of ECG for detecting carriers with LVH in families with the cardiac myosin-binding protein C, cardiac troponin T and cardiac troponin I gene mutations was 83%, 88% and 94% respectively. CONCLUSION: These findings suggest that ECG may have favourable diagnostic value even for detecting nonhypertrophic carriers. Furthermore, diagnostic value of ECG may differ according to the genes involved. Our data may contribute to interpretation of phenotypic differences between ECG and echocardiography from the viewpoint of molecular genetics of HCM.

PRKAR1A gene mutation in patients with cardiac myxoma.

BACKGROUND: PRKAR1A gene encodes the type 1A regulatory subunit of protein kinase A. The mutation of this gene causes Carney complex which is an autosomal dominant multiple neoplasia syndrome characterized by spotty pigmentations, endocrine overactivity and cardiac myxoma. We hypothesized that cardiac myxoma may be associated with PRKAR1A gene mutation and determined whether mutation in the PRKAR1A gene is the cause of familial and sporadic cardiac myxoma. METHODS: We studied seven patients (three males and four females) with cardiac myxoma. Two of them had familial cardiac myxoma complicated with Carney complex. The other five patients were characterized as sporadic cardiac myxomas. We analyzed the PRKAR1A gene of all patients by the polymerase chain reaction (PCR)-single-strand conformation method, followed with direct sequence analysis. RESULTS: We identified a novel mutation (494delTG) in exon 4A of the PRKAR1A gene in the patients with Carney complex. A 16-year-old proband had a left atrial myxoma, pituitary adenoma and skin pigmentation. His father also had left atrial myxoma and skin pigmentation. In contrast, no mutations in the PRKAR1A gene were identified in the other five patients with sporadic cardiac myxomas. CONCLUSIONS: These results suggest that mutation of the PRKAR1A gene may be associated with familial cardiac myxoma in Carney complex but may not be associated with sporadic cardiac myxoma.

QT dispersion and left ventricular morphology in patients with hypertrophic cardiomyopathy.

OBJECTIVE: To evaluate the relation between QT variables and disproportion of left ventricular wall hypertrophy in patients with hypertrophic cardiomyopathy. DESIGN: Retrospective analysis of the results of echocardiography and electrocardiography. SETTING: University hospital (tertiary referral centre). PATIENTS: 70 patients with hypertrophic cardiomyopathy were divided into four groups according to the distribution of left ventricular wall hypertrophy on cross sectional echocardiography: group A--hypertrophy confined to the interventricular septum; group B--hypertrophy confined to the interventricular septum and left ventricular anterior wall; group C--hypertrophy confined to the interventricular septum, left ventricular anterior wall, and lateral free wall; group D--hypertrophy involving all portions of the left ventricle. MAIN OUTCOME MEASURES: QT intervals and QT dispersion in precordial six lead ECGs. RESULTS: There were no significant differences in the maximum left ventricular wall thickness among the four groups, and maximum and minimum QTc intervals also did not differ. QTc dispersion was increased significantly in groups A and B compared with groups C and D. Dispersions of the interval from the J point to the end of the T wave (JTc dispersions) in groups A and B were also increased significantly compared with groups C and D. By linear regression analysis, QTc and JTc dispersions correlated with the ratio of the interventricular septal thickness to left ventricular posterior wall thickness (p = 0.0152 and p = 0.0075, respectively). CONCLUSIONS: QT dispersion may be affected by not only electrical inhomogeneity but also by morphological inhomogeneity of the left ventricle in patients with hypertrophic cardiomyopathy.

Differential screening-selected gene aberrative in neuroblastoma protein modulates inflammatory pain in the spinal dorsal horn.

Differential screening-selected gene aberrative in neuroblastoma (DAN) belongs to a novel gene family that includes the Xenopus head-inducing factor, Cerberus and the dorsalizing factor, Gremlin. It has been suggested that members of this family control diverse processes in growth, development and the cell cycle.Here, we demonstrate that the DAN protein is produced in the small neurons of the dorsal root ganglion and is transported to the nerve terminals in the spinal dorsal horn in adult rats. Furthermore, intrathecal injection of an antibody to the DAN protein suppressed inflammatory pain caused by the introduction of complete Freund's adjuvant or carrageenan into the rat hindpaw. The amount of mRNA for DAN in dorsal root ganglion neurons and of its expressed protein in the spinal dorsal horn were both increased in inflammatory models.Together, these data suggest that the DAN protein may be a novel neuromodulator in primary nociceptive nerve fibers.

Acute up-regulation of brain-derived neurotrophic factor expression resulting from experimentally induced injury in the rat spinal cord.

Brain-derived neurotrophic factor (BDNF), a member of the nerve growth factor family of trophic factors, has multiple functions including a role in the promotion of neuronal survival and nerve fiber elongation in both the central and the peripheral nervous systems. We assessed the expression of endogenous BDNF following an experimentally induced compression injury to the spinal cord. Expression of BDNF mRNA was increased following the spinal cord injury; reaching maximum levels 24 h after the injury. Expression of BDNF mRNA returned to the levels observed in sham-operated control animals within 3 days of the injury. Using the in situ hybridization technique, we observed a wide distribution of BDNF expression among the different cell types in the spinal cord, including motor and sensory neurons, and in glia cells, including astrocytes. We also observed expression of BDNF in putative macrophages and/or microglia; however, this effect was not observed until day 7 following spinal cord injury. These results suggest that BDNF is synthesized in both neurons and astrocytes during the acute response to injury to the spinal cord, functioning in a mainly neuroprotective role. This is followed by a later phase of expression in which BDNF is produced by macrophages and/or microglia, apparently functioning in a restorative capacity.

[A novel neurotransmitter, DAN, mediates pain sensation in the spinal dorsal horn].

Differential screening-selected gene aberrative in neuroblastoma(DAN) belongs to a novel gene family(DAN family) that includes the head-inducing factor, Cerberus, and dorsaling factor, Gremlin. It has been suggested that DAN family members control diverse processes in growth, development and the cell cycle. Here, we demonstrate that DAN is produced in the small neurons of the dorsal root ganglion(DRG) and transported to the nerve terminals in the spinal dorsal horn in adult rats. Furthermore, intrathecal injection of an antibody to DAN suppressed pain sensations induced by the application of complete Freund's adjuvant and carageenan into the rat hindpaw, and the amount of DAN mRNA in the DRG neurons and of DAN in the spinal dorsal horn were increased in the inflammatory models. These data suggest that DAN in a novel neurotransmitter and/or modulator in the primary sensory nerve fibers for pain sensation.

Cyclin-dependent kinase 4 and cyclin D1 are required for excitotoxin-induced neuronal cell death in vivo.

Systemic administration of the glutamic acid analog kainic acid (KA) causes neuronal cell death in brain-vulnerable regions, such as the piriform cortex, hippocampus, and amygdala in rats. We investigated the relationship between the KA-induced neuronal apoptosis and expression of cyclin-dependent kinase 4 (CDK4) and cyclin D1, key regulators of cell cycle progression. Expression of CDK4 and cyclin D1 was upregulated in neurons of the rat piriform cortex and amygdala 1-3 d after KA administration in vivo. CDK4 and cyclin D1 proteins were induced in the cytoplasm and nuclei of neurons, with a concomitant increase of CDK4- and cyclin D1-positive microglia in the affected areas. Continuous infusion of 100 microm CDK4 or cyclin D1 antisense oligonucleotides into the lateral ventricle using mini-osmotic pumps suppressed the excitotoxin-induced neuronal cell death in the piriform cortex and basolateral amygdaloid nucleus, whereas sense oligonucleotides exhibited no such effect. Although KA administration causes prolonged c-Fos expression in the vulnerable regions that preceded the induction of neuronal apoptosis, the CDK4 or cyclin D1 antisense oligonucleotides exhibited no suppressive effect on c-Fos levels. Our results suggest that CDK4 and cyclin D1 are essential for KA-induced neuronal apoptosis in vivo.

Increased QT dispersion does not reflect the increased regional variation of cardiac sympathetic nervous activity in hypertrophic cardiomyopathy.

BACKGROUND: QT dispersion (QTD) reflects regional variation of ventricular repolarization. However, the relationship between QTD and the regional variation of cardiac sympathetic nerve activity in hypertrophic cardiomyopathy (HCM) is not yet elucidated. METHODS: Cardiac sympathetic nerve activity was evaluated in 25 patients with HCM by iodine 123 metaiodobenzylguanidine (MIBG) myocardial scintigraphy. With planar MIBG imaging, heart and mediastinum ratios (H/M) at early (20 minutes) and delayed (3 hours) acquisition and the washout rate (WR) were calculated. Polar maps of left ventricular myocardium were divided into 20 segments. The SD of early uptake (EU-SD), delayed uptake (DU-SD), and WR (WR-SD) in 20 segments as indices of regional variation were calculated. QT intervals were corrected by use of the Bazett formula. RESULTS: Maximum QTc correlated positively with H/M early, WR, and left ventricular wall thickness (LVWT). Minimum QTc correlated positively with WR and LVWT. Corrected QTD (QTDc) correlated negatively with EU-SD, DU-SD, and WR-SD and positively with the interventricular septal thickness/posterior wall thickness ratio. Stepwise regression analysis revealed that the most powerful determinants for maximum QTc, minimum QTc, and QTDc were WR, LVWT, and EU-SD, respectively. CONCLUSIONS: QTD correlated negatively rather than positively with the regional variability index of cardiac sympathetic nerve activity. These results suggest that increased QTD in patients with HCM may not reflect increased heterogeneity of cardiac sympathetic nerve activity.

Arrhythmias in patients with Brugada-type electrocardiographic findings.

Brugada syndrome is characterized by marked ST-segment elevation in the right precordial leads (Bru-ECG) and is associated with a high risk for sudden death. However, it is unclear whether the arrhythmogenesis is caused by the mechanisms responsible for Bru-ECG. The present study investigated the risk of arrhythmias in patients with Bru-ECG by retrospectively analyzing 30 patients (28 men; mean age, 51+/-14 years) with Bru-ECG. Aborted sudden cardiac death (ventricular fibrillation or syncope) occurred in 9 patients (30%); paroxysmal atrial fibrillation was present in 9 (30%) patients in addition to malignant ventricular arrhythmias, and some type of arrhythmic event (aborted sudden cardiac death or paroxysmal atrial fibrillation) occurred in 15 patients (50%). Of all the arrhythmic events, 93% occurred at night or early in the morning, and 92% had pronounced ST-segment elevation. These results suggest that Bru-ECG may be associated not only with an increased risk of ventricular tachyarrhythmias but also with an increased risk of paroxysmal atrial fibrillation, and that the arrhythmogenesis may be related to the pronounced ST-segment elevation.

Cardiac troponin T Arg92Trp mutation and progression from hypertrophic to dilated cardiomyopathy.

BACKGROUND: Mutations in the cardiac troponin T gene causing familial hypertrophic cardiomyopathy (HCM) are associated with a very poor prognosis but only mild hypertrophy. To date, the serial morphologic changes in patients with HCM linked to cardiac troponin T gene mutations have not been reported. HYPOTHESIS: The aim of this study was to determine the long-term course of patients with familial HCM caused by the cardiac troponin T gene mutation, Arg92Trp. METHODS: In all, 140 probands with familial HCM were screened for mutations in the cardiac troponin T gene. RESULTS: The Arg92Trp missense mutation was present in 10 individuals from two unrelated pedigrees. They exhibited different cardiac morphologies: three had dilated cardiomyopathy-like features, five had asymmetric septal hypertrophy with normal left ventricular systolic function, one had electrocardiographic abnormalities without hypertrophy, and one had the disease-causing mutation but did not fulfill the clinical criteria for the disease. The mean maximum wall thickness was 14.1 +/- 6.0 mm. The three patients with dilated cardiomyopathy-like features had progressive left ventricular dilation. Three individuals underwent right ventricular endomyocardial biopsy. There was a modest degree of myocardial hypertrophy (myocyte diameter: 18.9 +/- 5.2 microm), and minimal myocardial disarray and mild fibrosis were noted. CONCLUSION: The Arg92Trp substitution in the cardiac troponin T gene shows a high degree of penetrance, moderate hypertrophy, and early progression to dilated cardiomyopathy in Japanese patients. Early identification of individuals with this mutation may provide the opportunity to evaluate the efficacy of early therapeutic interventions.

Quantitative assessment of diffuse coronary artery disease using a three-dimensional reconstruction method compared with intravascular ultrasound images.

BACKGROUND: It can be difficult to estimate the degree of stenosis in patients with diffuse coronary artery disease (CAD), because of the lack of a normal reference segment. If the size of normal coronary lumen has a direct relation to size of distal myocardial bed, it could be used to estimate the 'normal' cross-sectional area of coronary lumen. Accordingly, we could estimate the degree of stenosis of coronary arteries with diffuse disease by comparing them with calculated 'normal' areas of lumen. OBJECTIVE: To assess the validity of the above hypothesis. METHOD: Fourteen subjects without coronary atherosclerosis (group A) and 16 patients with CAD (group B) underwent simultaneous bidirectional coronary arteriography. Using these coronary arteriograms, we determined the relationship between cross-sectional area of coronary lumen measured by using a computerized edge-detection system and summed distal branch length calculated by using our computerized three-dimensional reconstruction method. RESULTS: For group A, we found a close correlation between area of lumen and branch length (r= 0.948). However, for group B, there were some segments for which the measured area of lumen was clearly smaller than that expected from the relationship for group A. From this relationship for group A, we calculated the stenosis ratios of 22 segments and, to confirm their accuracy, we compared the stenotic ratios with those measured on intravascular ultrasound images. The stenotic ratio of each segment of stenotic coronary artery calculated by our method agreed significantly well with the results obtained from the ultrasound measurements (r= 0.980). CONCLUSIONS: These observations validate a novel approach to quantifying diffuse CAD using clinical arteriograms.

Coronary lesion morphology and prognosis in young males with myocardial infarction with or without familial hypercholesterolemia.

The present study examined the angiographic characteristics and prognosis of young males under 40 years of age with acute myocardial infarction (AMI) and familial hypercholesterolemia (FH). The study group was divided into an FH group (n=16) and a non-FH group (n=27). Lesion morphology was classified as complex or smooth. Overall 36 patients were followed up for an average of 9.4 years. The frequency of angiographic normal or nonobstructive culprit lesions was significantly higher in the non-FH group (p<0.01). In contrast, the incidence of complex or totally occlusive lesions was higher in the FH group (p<0.01). At 10-year follow-up, survival rates from cardiac death (FH 85% vs non-FH 100%, p=0.06), from AMI (FH 43% vs non-FH 80%, p<0.05), and from any ischemic event at a new lesion (FH 9% vs non-FH 67%, p<0.01) were all reduced in the FH group. These results suggest that the mechanism of AMI in young male patients with FH differs from that in similar aged patients without FH, and that the overall prognosis of these patients is less favorable.

Systolic dysfunction and blood pressure responses to supine exercise in patients with hypertrophic cardiomyopathy.

Left ventricular function and blood pressure responses were evaluated in 56 patients with non-obstructive hypertrophic cardiomyopathy (HCM) and 12 control subjects by using a radionuclide ventricular function monitor during supine ergometer exercise. Patients with HCM were divided into 2 groups: (i) group A had no decrease in ejection fraction (EF) during exercise; and (ii) group B had a decrease in EF during exercise. During exercise, the change in end-diastolic volume did not differ between the 3 groups. In contrast, the change in end-systolic volume differed between the 3 groups (p<0.0001). The change in systolic blood pressure (SBP) also differed significantly between the 3 groups. The change in SBP in group B was smaller than that in the control group and group A, and changes in the EF and changes in the SBP between rest and peak exercise showed a significant correlation (p<0.005). These results suggest that exercise-induced systolic dysfunction in patients with non-obstructive HCM may contribute to abnormal blood pressure response in those patients.

Collagen remodeling and cardiac dysfunction in patients with hypertrophic cardiomyopathy: the significance of type III and VI collagens.

BACKGROUND: The relationship between the extent of myocardial interstitial fibrosis, the percentage of each type of collagen, and cardiac function in patients with hypertrophic cardiomyopathy (HC) has not been established. HYPOTHESIS: The study aimed to establish that increases in some types of collagen may correlate with cardiac dysfunction. METHODS: Mallory-Azan staining and immunohistochemical staining by the avidin-biotin-complex (ABC) method using anticollagen antibodies were performed on the myocardial biopsy specimens in 35 patients with HC, and the percentage and type of collagen present was determined. Left ventricular (LV) function was evaluated by cardiac catheterization and ventriculography. RESULTS: The percentage of myocardial interstitial fibrosis correlated highly with indices of LV diastolic and systolic function. The amount of type III collagen correlated significantly with the peak negative dp/dt, the rapid filling volume/stroke volume, and the ejection fraction (EF). Significant correlations also were noted between the amount of type VI collagen and peak negative dp/dt, peak positive dp/dt, and EF. Type I collagen did not correlate with any of the LV function indices, and type IV collagen correlated only with peak ejection rate. Type V collagen did not accumulate substantially in the myocardial interstitium. CONCLUSIONS: The progression of myocardial interstitial fibrosis in the HC heart adversely impacts both the diastolic and systolic function of the LV. Increases in the percentage of type III and VI collagen correlate with cardiac dysfunction.

Acute increases in plasma oxidized low-density lipoprotein immediately after percutaneous transluminal coronary angioplasty.

To investigate the acute changes in plasma oxidized low-density lipoprotein before and immediately after coronary angioplasty, we studied 132 consecutive patients who successfully underwent this procedure. Plasma oxidized low-density lipoprotein levels were significantly increased immediately after coronary angioplasty in patients with stable angina pectoris as well as in those with acute coronary syndromes.

Morphological change of substance P receptor immunoreactive dendrites of preganglionic sympathetic neurons.

Substance P (SP)-containing terminals and SP receptors (SPRs) are found on the dendrites of preganglionic sympathetic neurons (PSNs) in the intermedio-lateral nucleus (IML) of the spinal cord. The SP-containing fibers were thought to be of supraspinal origin. However, the primary sensory nerve fibers terminated around PSNs, and some of them directly on PSNs. We observed approximately 150 SPR-immunoreactive (ir) varicosities on the dendrites of PSNs in slices of the first thoracic segment (T1) in control rats. The number of varicosities decreased to 41% 14 days after hemisection of the spinal cord at the fourth cervical segment (C4), and to 55% 14 days after sectioning the spinal dorsal roots at the C8 and T1 levels. The number of varicosities decreased by 33% in 8-week-old rats which had been administered capsaicin subcutaneously within 24 hours after birth to eradicate unmyelinated sensory fibers. However, varicosities increased by 15% 15 minutes after injection of capsaicin into the plantar surface of the front paw to stimulate somatosensory nerve fibers in adult rats. The results demonstrate that SPR-ir varicosities on the dendrites of PSNs were modulated not only by the supraspinal nervous system but also directly by the primary sensory nerve terminals.