Comprehensive Evaluation of (+)-Usnic Acid-induced Cardiotoxicity in Rats by Sequential Cross-omics Analysis.

Two-week administration of (+)-usnic acid (UA) induces mitochondrial swelling of cardiomyocytes, and toxicogenomic analysis of the heart revealed upregulation of oxidative stress, amino acid limitation, and endoplasmic reticulum stress-related genes in rats. To analyze the pathogenesis, UA was orally administrated to rats for 1, 4, 7, and 14 days, and sequential histopathological, genomic, and metabolomic analyses were performed on the heart, liver, and plasma. As a result, mitochondrial swelling of cardiomyocytes was observed on day 15 preceded by genomic upregulation on days 5 and 8. Of the focused gene groups, amino acid limitation-related genes represented by Mthfd2 showed numerically higher values or upregulation from day 5, which was sustained through the experimental period. On the contrary, oxidative stress-related genes were upregulated temporally on day 5. In metabolomic analysis, amino acids such as taurocholate and their metabolites fluctuated in concert with the upregulation of amino acid limitation-related genes in the heart, liver, and plasma. Moreover, accumulations of bile acids were manifested in all the tested tissues, while no histopathological change was seen in the liver. Increased bile acids might have an indirect effect on the myocardium; however, more detailed analysis is required. In conclusion, amino acid limitation was suggested as the pivotal toxic trigger of UA-induced cardiotoxicity.

Species-specific differences in coumarin-induced hepatotoxicity as an example toxicogenomics-based approach to assessing risk of toxicity to humans.

One expected result from toxicogenomics technology is to overcome the barrier because of species-specific differences in prediction of clinical toxicity using animals. The present study serves as a model case to test if the well-known species-specific difference in the toxicity of coumarin could be elucidated using comprehensive gene expression data from rat in-vivo, rat in-vitro, and human in-vitro systems. Coumarin 150 mg/kg produced obvious pathological changes in the liver of rats after repeated administration for 7 days or more. Moreover, 24 h after a single dose, we observed minor and transient morphological changes, suggesting that some early events leading to hepatic injury occur soon after coumarin is administered to rats. Comprehensive gene expression changes were analyzed using an Affymetrix GeneChip approach, and differentially expressed probe sets were statistically extracted. The changes in expression of the selected probe sets were further examined in primary cultured rat hepatocytes exposed to coumarin, and differentially expressed probe sets common to the in-vivo and in-vitro datasets were selected for further study. These contained many genes related to glutathione metabolism and the oxidative stress response. To incorporate human data, human hepatocyte cultured cells were exposed to coumarin and changes in expression of the bridging gene set were examined. In total, we identified 14 up-regulated and 11 down-regulated probe sets representing rat-human bridging genes. The overall responsiveness of these genes to coumarin was much higher in rats than humans, consistent with the reported species difference in coumarin toxicity. Next, we examined changes in expression of the rat-human bridging genes in cultured rat and human hepatocytes treated with another hepatotoxicant, diclofenac sodium, for which hepatotoxicity does not differ between the species. Both rat and human hepatocytes responded to the marker genes to the same extent when the same concentrations of diclofenac sodium were exposed. We conclude that toxicogenomics-based approaches show promise for overcoming species-specific differences that create a bottleneck in analysis of the toxicity of potential therapeutic treatments.

Pharbitis class-1 knotted-like homeobox gene, PKn3, shares similar characteristics to those of class-2 knotted-like genes.

Three novel homeobox genes, PKn1-3 (Pharbitis knotted-like), were isolated from Japanese morning glory (Pharbitis nil Chois, strain Violet). A sequence analysis showed that these genes belong to the knotted class-1 gene family and that PKn3 has a relatively unique sequence. All PKn genes are expressed in shoot apices, stems and roots, but not in cotyledons. Transformed tobacco with PKn1 or PKn2 displayed leaf shrinkage and a dwarf phenotype, while the ectopic expression of PKn3 gave no altered phenotypes. In situ hybridization showed that PKn3 is up-regulated in developing leaf primordia and that this expression becomes restricted in the basal region of young leaf blades, which is reminiscent of the expression pattern of the class-2 knotted gene, NTH23. These data suggest that these Pharbitis homeobox genes participate in the differentiation in shoots and suggest a unique function of PKn3 in developing leaves.

[A case of video-assisted thoracoscopic surgery for patent ductus arteriosus under transesophageal echocardiography].

A six-year-old boy with patent ductus arteriosus was successfully treated by thoracoscopic surgery under transesophageal echocardiography, by which interruption of the ductal flow was confirmed. Postoperative course was uneventful and the patient was discharged on the 3rd postoperative day. The transesophageal echocardiography was effective to confirm disappearance of the flow in the operating room real-time. Video-assisted endoscopic surgery have reduced operative trauma in adult thoracic and general surgery, and can be safely applied to pediatric patients with patent ductus arteriosus. This technique may be an effective addition to the staged management of more complex forms of congenital heart disease.

[Electrophysiologic effects of intravenous digoxin in infants and children with Wolff-Parkinson-White syndrome].

Electrophysiologic properties of the accessory pathway were investigated before and after the intravenous administration of digoxin (0.01-0.02 mg/kg) during electrophysiologic studies in 14 infants and children with the Wolff-Parkinson-White syndrome. Determination of electrophysiologic properties of the accessory pathway was made using transesophageal atrial pacing and/or intracardiac right atrial pacing. Maximal effect on the accessory pathway after intravenous digoxin was observed during one to six hours. Effective refractory period of the accessory pathway increased in 6 of the 14 patients, decreased in 4 and unchanged in 4. Shortest AP 1:1 conduction increased in 5 of the 12 patients, decreased in 3 and unchanged in 4. Tachycardia was not induced after digoxin in only one patient. Tachycardia cycle length, ventriculoatrial conduction time and atrioventricular conduction time were unchanged after digoxin in almost all cases. Thus, digoxin is not the first choice drug for termination and prevention of the preexcitation syndrome.

PPARα-mediated responses in human adult liver stem cells: In vivo/in vitro and cross-species comparisons.

The peroxisome proliferator-activated receptor α (PPARα) is a ligand-activated transcription factor that regulates a variety of biological processes including lipid metabolism and energy homeostasis. Peroxisome proliferators (PPs) are carcinogens in rodents, while humans are resistant to peroxisome proliferation and carcinogenesis. In this study, we examined the differential gene expression elicited by clofibrate (CLO) and WY-14,643 (WY) in C57BL/6 mouse liver compared to responses in human HepG2 hepatoma and HL1-1 adult stem cells. Mice were gavaged with sesame oil, 300mg/kg CLO or WY for 2, 4, 8, 12, 18 or 24h, or daily for 4 or 14 days. Although no significant changes in body weight gain were observed, WY induced relative liver weight at 4 and 14 days. Genome-wide hepatic gene expression analysis identified 719 and 1443 differentially expressed unique genes elicited by CLO and WY, respectively (|fold change|>1.5, P1(t)>0.99). Functional analysis associated the gene expression changes with lipid metabolism, transport, cell cycle and immune response. Most differentially expressed genes were in common to both treatments and clustered together only at early time points (2-8h). Complementary QRT-PCR studies in human HL1-1 and HepG2 cells treated with 50µM WY or DMSO for 1, 2, 4, 8, 12, 24 or 48h identified a minimal number of conserved orthologous responses (e.g., Pdk4, Adfp and Angptl4) while some genes (i.e., Bmf, a tumor suppressor) exhibited induction in human cells but repression in mice. These data suggest that PPs elicit species-specific PPARα-mediated gene expression.

Anthracycline-induced congestive heart failure in two pediatric leukemia cases and long term follow-up.

Endomyocardial biopsy was performed on two leukemia patients who had recovered from severe congestive heart failure (CHF) due to anthracycline cardiomyopathy at 41 months and 47 months after CHF. Microscopic myocardial findings in both patients revealed that myocytes were hypertrophic, but interstitial fibrosis was not observed, suggesting a compensatory mechanism for the damaged heart muscle during the acute episode of CHF. The improvement of clinical symptoms and the normalization of cardiac function, including fractional shortening and ECG changes, is thought to have been associated with this myocardial repairing process.

Childhood drownings and near-drownings in Japan.

In Japan, the leading cause of death for children over 1 year old is injury, and for children aged 0-14, drowning is the second leading cause of death. The purpose of the present study was to describe the epidemiological factors of drownings and near-drowning among Japanese children and to ascertain whether there are characteristic patterns for different age groups. Epidemiologic data was obtained by questionnaire. A total of 604 cases of submersion injuries were reported from 49 hospitals located in 22 Japanese prefectures. In the present paper, victims of drowning (n = 134) and near-drowning with permanent severe brain damage (n = 51) and those of near-drowning with intact survival or mild impairment (n = 419) were investigated. Preschool-aged children, especially toddlers, are at the greatest risk of drowning and near-drowning, and for children over 2 years of age, boys have three times greater risk than girls. The bathtub is the most common place of submersion injuries in Japan, especially for children under 4 years of age. The important risk factors for the victims who died or were severely impaired were associated with duration of submersion and necessity of emergency cardiopulmonary resuscitation on arrival at hospital.

Asymptomatic myocardial infarction in Kawasaki disease: long-term prognosis.

Eight patients with Kawasaki disease who had sustained asymptomatic myocardial infarction 8-15 years ago (mean, 13.1 years) were reexamined by various noninvasive cardiac function tests to assess long-term prognosis. At present, electrocardiograms (ECGs) are normal in six patients. However, all eight patients had a prolonged preejection period (PEP) to left ventricular ejection time (LVET) ratio 30 s after amylnitrate (AN) inhalation. Six patients had perfusion defects by exercise thallium-201 myocardial scintigraphy, and two patients developed ST segment depression in treadmill exercise testing. These patients are symptom-free even though their physical activity has not been restricted. Yet they proved to have serious abnormalities suggesting sequelae of myocardial infarction or existing myocardial ischemia. Judging from the results of noninvasive cardiac function tests and recently performed coronary angiography, five of the eight patients require coronary bypass surgery.

Optimal dosage and differences in therapeutic efficacy of IGIV in Kawasaki disease.

In an initial study, three groups of patients with Kawasaki disease received either aspirin alone or alkylated immunoglobulin G intravenous preparation (IGIV) 200 mg/kg daily x 3 days + aspirin, or 400 mg/kg alkylated IGIV daily x 3 days + aspirin. In a second study, three groups of patients were treated with either 100, 200 or 400 mg/kg of native IGIV in combination with aspirin daily for 5 days. While the regimen of 200 mg/kg native IGIV daily x 5 days was found to be effective, the incidence of coronary artery lesions (CAL) was even less on a regimen of 400 mg/kg daily x 5 days. It is therefore suggested that a better therapeutic effect can be achieved with a 400 mg/kg dose of native IGIV. Based on the results from these two studies, it is assumed that native IGIV is more effective in inhibiting CAL formation and persistence than the chemically modified preparation in which the biological activity of the Fc region in the immunoglobulin G molecule is altered.

Muscular changes in Engelmann's disease.

In a case of Engelmann's disease in an 11-year-old Japanese boy the muscular changes were studied in detail. Muscle weakness was maximal about the pelvic girdle. Muscle biopsy showed the selective atrophy of type II fibres, and no degenerative change could be seen histologically, histochemically, or electron-microscopically. Although the distribution of muscular weakness in Engelmann's disease is similar to that of a progressive muscular dystrophy, the disease does not seem to be a myopathy.

Aneurysms of the coronary arteries in Kawasaki disease. An angiographic study of 30 cases.

Thirty patients with coronary aneurysms associated with Kawasaki disease underwent coronary arteriography. Of 53 aneurysms, five were saccular, 24 sacculofusiform, 19 fusiform and five tubular. When tubular aneurysms were included in the fusiform type, the incidence of each configuration in the right coronary artery was almost the same as that in the left coronary artery. The left anterior descending coronary artery had the most aneurysms, followed by the right coronary, left main and circumflex arteries. Right coronary aneurysms always involved the bifurcation or the region from which a branch vessel arose; 13 of 31 left coronary aneurysms did not involve the bifurcation.

Stokes-Adams attacks due to acute nonspecific myocarditis in childhood.

Six patients aged between 1 to 11 years (4 females and 2 males) developed Stokes-Adams attacks with complete heart block due to acute nonspecific myocarditis. Transvenous pacing was instituted in 2 patients, but in the other 4 patients the ECG returned to normal by isoproterenol. All ECGs in complete heart block showed QRS complexes of right bundle branch block with left posterior hemiblock pattern, except for 1 which showed QRS complexes of complete left bundle branch block pattern. The ECG improved sequentially in order and left anterior hemiblock pattern of QRS complexes remained to the last during the convalescent period. Normal atrioventricular conduction returned by 2 to 24 hours in all but 1 patient who was dead and 1 of the 2 patients with shock. In another patient bifascicular block has persisted.

Intravenous gamma-globulin for Kawasaki disease.

We studied the effect of gamma-globulin (IVGG) and aspirin (ASA) on the development of the coronary artery lesions (CAL) of Kawasaki disease (KD) in three different protocols. Within 29 days of the onset of KD the echocardiographic evidence of CAL had developed in 39-42% of the patients in the ASA group, but only in 13.7-20.8% of the patients treated with IVGG (200 or 400 mg/kg X 5). In long-term follow-up observation of CAL of these patients the evidence of CAL in both the ASA and the IVGG group regressed gradually; however, the residual rate of CAL was significantly low in the IVGG group at all times up to 24 months after onset. These facts suggest that when using IVGG for KD, we should select a dose of intact gamma-globulin, 1,000 mg/kg or more in total, to prevent the occurrence of CAL. We have demonstrated not only a significant reduction in the occurrence of CAL in patients treated with IVGG but a reduction in the residual rate of CAL for two years as compared with those treated by ASA.

High-dose intravenous gammaglobulin for Kawasaki disease.

The ability of high-dose intravenous gammaglobulin (IVGG) to prevent the coronary artery lesion of Kawasaki disease has been studied in a multicentre controlled trial of IVGG plus aspirin versus aspirin alone, aspirin being the conventional treatment for Kawasaki disease. Patients were allocated at random to aspirin (45 cases) or IVGG (40 cases), there being no significant intergroup differences in age, sex ratio, duration of disease until the start of treatment, or severity. The development of coronary artery dilatation was monitored by two-dimensional echocardiography. Within 29 days of the onset of the disease, this lesion had developed in 19 cases (42%) in the aspirin group and in 6 cases (15%) in the IVGG group. There were no new instances of this lesion: in the period 30-60 days coronary artery dilatation persisted in 14 and 3 cases, respectively. In patients found to have echocardiographic abnormalities selective coronary arteriography was done 30-60 days after onset of Kawasaki disease and the lesion was confirmed in 1 of the 6 cases in the IVGG group and in 11 of the 19 controls. High-dose IVGG seems to reduce the frequency of coronary artery abnormalities in patients with Kawasaki disease.