Radioactive iodine (RAI) therapy for distantly metastatic differentiated thyroid cancer (DTC) in juvenile versus adult patients

In general, juvenile differentiated thyroid carcinoma (DTC) demonstrate indolent characteristics and favorable prognosis are observed in comparison with many other carcinomas. However, recurrence is frequent, necessitating additional treatment, including radioactive iodine (RAI) therapy. In this report, the probability of recurrence, prognostic factors, treatment, and outcomes in both juvenile- and adult-onset DTC were analyzed and compared. At our institution, a total of 1552 DTC patients underwent thyroidectomy and/or lymph node dissection. The patients included 23 in their teens, 118 in their twenties, and 1412 in their thirties or older. The risk factors for distant metastases for DTC were male gender, follicular carcinoma, size of the PTC primary tumor, cervical lymph node metastases from PTC, and the presence of more than two distant metastatic foci. Patients with the highest risk underwent RAI ablation in line with institutional guidelines. Although the overall outcome in our juvenile patients was excellent, during follow-up, 4 (17.4%) of the 23 patients developed recurrent disease: 91.3% achieved complete remission, 4.35% partial remission, and 4.35% stable disease, with no disease-related deaths. Among the 118 patients in their twenties to thirties, 1 (0.8%) experienced progressive disease and disease-related death. A younger age at diagnosis and less radical primary surgery without subsequent RAI ablation are factors strongly predictive of distant metastases in patients with juvenile-onset DTC. To reduce the rate of relapse and improve surveillance for recurrent disease, total thyroidectomy followed by RAI appears to be the most beneficial initial treatment for patients with high- and intermediate-risk juvenile DTC.

Epidemiological characteristics of rubella and congenital rubella syndrome in the 2012-2013 epidemics in Tokyo, Japan

A large rubella outbreak has been observed since June 2012 in Tokyo, Japan, and a rapid increase in the number of congenital rubella syndrome (CRS) cases have also been reported in Japan since October 2012. All the clinically diagnosed and laboratory-confirmed rubella cases reported in Tokyo from January 2012 to December 2013 and all the laboratory-confirmed CRS cases from January 2012 to March 2014 were analyzed. In total, 4,116 rubella cases were reported in Tokyo. Of these, 77.2% (n=3,176) were male; the highest number of cases occurred in males aged 35-39 years and in females aged 20-24 years. Complications included arthralgia/arthritis (19.4%), thrombocytopenic purpura (0.5%), hepatic dysfunction (0.3%), and encephalitis (0.1%). The circulating rubella virus in Tokyo was genotype 2B. The most possible site of transmission was the workplace. Because of the rubella epidemic, 16 CRS cases were reported in Tokyo from March 2013 to February 2014. Domestic infection with rubella was proven for all mothers of 16 cases. This situation suggests that Japan is still working to achieve rubella elimination.

Thyroglobulin suppresses thyroid-specific gene expression in cultures of normal but not neoplastic human thyroid follicular cells

CONTEXT

It was shown in the rat thyroid that thyroglobulin (Tg) stored in the follicular lumen is a potent regulator of thyroid-specific gene expression to maintain the function of individual follicles. However, the actions of Tg as a regulatory molecule in human thyroid have not been studied.

OBJECTIVE

Our objective was to determine the effect of Tg on gene expression in normal and diseased human thyroid and to examine whether the proposed model of negative-feedback autocrine regulation of thyroid function by Tg is applicable in the human as well as the rat.

DESIGN

Primary cultures of human thyrocytes were established from normal thyroid, Graves' disease thyroid, adenomatous goiter, follicular adenoma, and papillary carcinoma tissues obtained during surgery. Cells were stimulated with physiologic (ie, follicular) concentrations of Tg, and mRNA and protein expression of genes involved in thyroid hormonogenesis were evaluated. The effects of Tg on thyroid-specific gene expression were also assessed in 2 human papillary carcinoma cell lines.

RESULTS

Transcript levels of genes participating in thyroid hormone biosynthesis were significantly reduced by Tg in thyrocyte cultures derived from normal and Graves' thyroid, but not in cultures derived from thyroid neoplasms and adenomatous goiter.

CONCLUSION

It was confirmed that Tg acts as a negative-feedback regulator of gene expression in human thyrocytes, suggesting that Tg signaling may constitute a common mechanism for maintaining thyroid homeostasis in species with follicular thyroid morphology. However, certain diseases of intrinsic thyroid overgrowth appear to be associated with an escape from the regulatory mechanism of Tg.

Biological differential diagnosis of follicular thyroid tumor and Hürthle cell tumor on the basis of telomere length and hTERT expression

BACKGROUND

The most difficult thyroid tumors to diagnose by histology are follicular carcinomas (FTCs) and Hürthle cell carcinomas (HCCs). Telomere alteration and human telomerase reverse transcriptase (hTERT) expression have been observed in most human cancers and are known to be a feature of malignancy. The purpose of this study was to clarify whether hTERT protein expression and telomere alteration could be applicable biological markers for distinguishing FTC from HCC.

METHODS

We investigated a total of 78 thyroid tumor cases, including 14 FTCs, 47 follicular adenomas (FTAs), 5 HCCs, and 12 Hürthle cell adenomas (HCAs). hTERT protein expression was examined by immunohistochemistry, and telomere length was determined by tissue quantitative fluorescence in situ hybridization.

RESULTS

Positivity for hTERT protein expression was observed in 86 % of FTCs and 49 % of FTAs. Telomeres in FTCs were significantly shorter than those in FTAs. All HCCs and HCAs (100 %) expressed hTERT protein. Telomeres in HCCs were significantly shorter than those in HCAs.

CONCLUSIONS

Our results suggest that hTERT protein expression and telomere shortening would be applicable as biological markers to distinguish FTC from FTA. Previous studies have suggested that follicular tumor and Hürthle cell tumor should be classified biologically as distinct tumors. All Hürthle cell tumors expressed hTERT protein and HCCs had markedly shortened telomeres, suggesting that follicular tumor and Hürthle cell tumor might be biologically distinct entities.

Therapeutic strategy for low-risk thyroid cancer in Kanaji Thyroid Hospital

It is well-known that differentiated thyroid carcinoma (DTC) has a generally indolent character and shows a favorable prognosis in comparison with many other carcinomas. The therapeutic strategy for patients with DTC in Japan has differed from that in Western countries. Total thyroidectomy followed by radioactive iodine (RAI) ablation has been standard in Western countries, whereas limited hemi-thyroidectomy and subtotal thyroidectomy has been extensively accepted in Japan. Papillary thyroid carcinoma (PTC) accounts for over 90% of all thyroid cancers in Japan. The majority of patients with PTC are categorized into a low-risk group on the basis of the recent risk-group classification schemes, and they show excellent outcomes. Several management guidelines for thyroid cancers have been published in Western countries. However, the optimal therapeutic options for PTC remain controversial, and high-level clinical evidence aimed at resolving these issues is lacking. Moreover, as socioeconomic differences in medical care exist, conventional policies for the treatment of PTC have differed between Japan and other countries. This review focuses on the special features of treatment in Japan for patients with low-risk DTC involving subtotal thyroidectomy without adjuvant therapies, rather than total thyroidectomy with RAI, with the aim of preserving quality of life. At our institution in Japan, we have had extensive experience with RAI treatment for high-risk DTC patients, and this represents a very rare situation. Here we introduce the therapeutic strategy for low-risk thyroid cancer in Japan, including the measures adopted at our institution.

[The 2011 measles outbreak in Tokyo. An analysis of surveillance data]

OBJECTIVES

The study was conducted with the intention of establishing a strategy to eliminate measles on the basis of an analysis of the epidemiological profile of measles cases reported in Tokyo during the year 2011.

METHODS

We investigated measles cases reported to the Tokyo Metropolitan Government in 2011, recorded as part of the National Epidemiological Surveillance of Infectious Diseases. Factors analyzed included age, vaccination status for each patient, cases for which records were discarded after laboratory confirmation, genotype of the measles virus and relationships between dates of specimen collection and results of polymerase chain reaction (PCR) and IgM antibody tests.

RESULTS

A total of 178 measles cases were reported in Tokyo during 2011, and the majority of cases (128, 71.9%) were reported during the peak period from epiweeks 13 to 24. The largest age group reported was one to four years of age (40, 22.5%) followed by groups of 20-29 and 30-39 years of age (both 34, 19.1%). Most cases were sporadic, with only six outbreaks occurring. Even then, the numbers of cases for each outbreak was less than five. More than half of the patients in all age groups, except for the 1-4-year-old group, had not been vaccinated or did not have a record of vaccination. Genotypes D4 and D9 of measles virus were detected in most cases. However, genotype D5, which had been circulating in Japan before 2008, was not detected.

CONCLUSION

Imported viruses were the cause of measles cases reported in Tokyo during 2011. The disease control was better than that in 2007 and 2008 because of the swift and appropriate responses to the occurrences. It is also possible that there has been an increase in the proportion of people with immunity to measles. Increasing the rate of immunization, performing effective surveillance, and confirming suspicious measles cases by using molecular methods are important for achieving the elimination of measles.

Ongoing rubella outbreak among adults in Tokyo, Japan, June 2012 to April 2013

INTRODUCTION

A large rubella outbreak has been occurring in Tokyo, Japan since June 2012. Rubella vaccination, introduced in Japan in 1976, has targeted different age groups, resulting in a large proportion of the current population being unvaccinated.

METHODS

Rubella cases reported in Tokyo from 2 January 2012 to 21 April 2013 were analysed. A clinical case had generalized maculopapular rash, fever and lymphadenopathy; a laboratory-confirmed case was a clinical case with a positive serology or polymerase chain reaction test for rubella. A descriptive analysis of cases by age, sex, vaccination history and other epidemiological information was conducted.

RESULTS

A total of 2382 cases were reported from all areas of Tokyo. Three-quarters were male (n = 1823; 76.5%); the highest number of cases occurred among males aged 35-39 years and females aged 20-24 years. About a third of males (27%) and females (32%) reported never receiving rubella vaccination, with 68% and 56%, respectively, having an unknown vaccination status.

DISCUSSION

This outbreak reflects the changing, yet incomplete, immunization policies for rubella in Japan that may increase the risk of congenital rubella syndrome (CRS). To suppress the outbreak of rubella and prevent CRS cases, we recommend vaccination for the entire susceptible population.

Amplification of the human epidermal growth factor receptor 2 gene in differentiated thyroid cancer correlates with telomere shortening

The human epidermal growth factor receptor 2 (HER2) proto-oncogene plays an important role in the development and progression of breast and gastric cancer. Monitoring of the HER2 status and treatment with trastuzumab was performed initially in breast cancer, and subsequently in gastric cancer. However, the HER2 status of thyroid cancer remains unexplored. Telomere alteration and telomerase activity have been observed in most human cancers and are known to be a feature of malignancy. The aims of this study were to clarify the HER2 status of thyroid cancer and to examine any correlations to various characteristics of malignancy. We investigated 69 cases of differentiated thyroid cancers with reference to: i) telomere length as measured using tissue quantitative fluorescence in situ hybridization (Q-FISH), ii) expression of human telomerase reverse transcriptase (hTERT) as determined by immunohistochemistry (IHC), and iii) overexpression of the HER2 protein as determined by IHC and amplification of the HER2 gene as determined by fluorescence in situ hybridization (FISH). The telomeres of thyroid cancers, especially follicular carcinomas, were significantly shorter compared to those of adjacent normal tissues. Positivity for hTERT expression and HER2 amplification were observed in approximately 70 and 22% of thyroid cancers, respectively. Our data demonstrated that telomeres in HER2-positive cancers were significantly shorter compared to those in HER2-negative cancers. These results suggest that highly malignant differentiated thyroid cancer can be detected by monitoring HER2 status and telomere shortening, and that trastuzumab therapy may be effective for refractory thyroid cancer.

[The possibility of outbreak control by real-time surveillance with PCR method perfomed immediately--a case study of hand foot and mouth disease outbreak in a day care facility for children]

OBJECT

We examined the relationship between syndromic surveillance and laboratory confirmation, at an early stage of an outbreak of hand foot and mouth disease and RS virus infection.

METHOD

We observed the epidemiological situation from a surveillance system at a day care facility for young children in Tokyo from one week before onset of the indicator until one month thereafter. For laboratory diagnosis, we collected a rectal swab or a nasal swab from one patient in the early stage of the outbreak.

RESULT

A total of 20 patients, comprising 12 1-year-old, 5 2-year-old and 3 3-year-old children, were found to have hand foot and mouth disease on August 1st, 2011. From a rectal swab from one HFMD patient, enterovirus genome was detected and identified as coxsackievirus type A6 (CA6) with PCR sequencing. The CA6 had 99% identity to CA6 (Genbank No AB663318) in the VP4 coding region. RS virus also was detected from a nasal swab.

DISCUSSION

The establishment of a surveillance system at day care facilities for children can monitor infectious diseases among young children promptly. Laboratory confirmation, even though from only one patient as shown in this study, can provide critical information regarding the causative agent of the outbreak. This method is easy to conduct and could be used for activating appropriate countermeasures.

CONCLUSION

We believe that the combination of the timeliness of a surveillance system at day care facility for children and the convenience of laboratory diagnosis of even one patient can detect the causative pathogen, and thus enable the activation of countermeasures before an outbreak become widespread.

[Relationship between BCG immunization coverage and the immunization delivery system in the Tama area of Tokyo]

PURPOSE

The BCG immunization has long been performed in Japan. Although the BCG immunization service is the responsibility of the municipality, the manner in which the BCG immunization is delivered differs from municipality to municipality. The purpose of this study was to clarify how the different manner of the BCG immunization delivery systems influenced the BCG immunization coverage.

METHODS

The study of BCG immunization coverage was conducted in the Tama area located in the western suburbs of Tokyo in 2004. The birth data and the immunization history by the age of 3 years were collected in the three-year-old health check-up from a total of 2,341 children residing in the Tama area. Based on the age at immunization for each child, the BCG immunization coverage was calculated according to the types of the BCG immunization delivery system. The immunization types were defined as follows; the BCG immunization given on the occasion of the mass health check-up (Group 1); the exclusive mass BCG immunization in a monthly service (Group 2); the exclusive mass BCG immunization in a bimonthly service (Group 3); the exclusive mass BCG immunization in services of fewer than every two months (Group 4); and the immunization given on an individual basis by a general practitioner (Group 5). A univariate analysis was performed to examine the relationship between the BCG immunization coverage by the age of 6 months and the difference among the BCG immunization delivery systems, followed by a multivariate regression analysis to adjust for the factors related to the demography, health care services and the socio-economic status of the municipalities.

RESULTS

Unadjusted odds ratios and adjusted odds ratios for BCG unimmunized children under the age of 6 months by the BCG immunization delivery manner groups were OR 1 reference, adj. OR 1 reference in Group 1; OR 1.42 CI 0.87-2.29, adj. OR 4.01 CI 2.24-7.11 in Group 2; OR 4.96 CI 3.66-6.82, adj. OR 15.59 CI 10.10-24.49 in Group 3;OR 18.60 CI 13.77-25.49, adj. OR 48.17 CI 29.62-79.75 in Group 4; and OR 4.24 CI 2.86-6.31, adj. OR 15.61 CI 9.05-27.26 in Group 5. The univariate analysis and multivariate regression analysis revealed an influence of the BCG immunization delivery manner on the BCG immunization coverage.

CONCLUSION

The choice of BCG immunization delivery manner is very important to raise the BCG immunization coverage. The BCG immunization given on the occasion of the mass health check-up and the high-frequent immunization service are thought to improve the BCG immunization coverage.

Low-dose dobutamine radionuclide ventriculography for prediction of myocardial viability: quantitative analysis of regional left ventricular function

BACKGROUND

It is important to distinguish viable myocardium from necrotic tissue in order to decide upon therapy in patients with ischemic heart disease.

HYPOTHESIS

We verified the hypothesis that quantitative analysis of regional left ventricular function using low-dose dobutamine radionuclide ventriculography (RNV) can sensitively predict myocardial viability and compared its usefulness with thallium-201 (201Tl) single-photon emission computed tomography (201Tl-SPECT).

METHODS

Radionuclide ventriculography at rest and during low-dose dobutamine infusion (5 micrograms/kg/min), 201Tl-SPECT, and coronary angiography were performed in 51 subjects with severe ischemia-related stenosis of coronary arteries and 3 subjects without coronary artery disease. 201Tl uptake was assessed as normal (control), low perfusion (LP), or defect. We compared the response of regional function to dobutamine with the regional 201Tl uptake. The accuracy of both methods for identifying viable myocardium was investigated in 17 patients who underwent successful coronary revascularization, with a resulting improvement in wall motion.

RESULTS

The increase in regional ejection fraction (delta r-EF) in response to dobutamine was significantly greater in the control (12 +/- 6%) and LP (16 +/- 11%) regions than in the defect (5 +/- 10%) regions. The increase in one-third regional ejection fraction (delta r-1/3EF) was also significantly higher in the control (14 +/- 7%) and LP (10 +/- 8%) regions than in the defect regions (5 +/- 6%). We defined myocardial viability as a delta r-EF > 5% or a delta r-1/3EF > 2%. The sensitivity and specificity of the delta r-EF for identification of myocardial viability were 91.4 and 55.5%, respectively. The sensitivity and specificity of the delta r-1/3EF were 91.4 and 66.6%, respectively; the corresponding values for 201Tl SPECT were 74.2 and 77.8%.

CONCLUSION

Low-dose dobutamine RNV with quantitative analysis of regional left ventricular function was more sensitive for identification of viable myocardium than 201Tl-SPECT.

[Variation in yield of needle scars with multipuncture BCG vaccination]

PURPOSE

BCG vaccination using the multipuncture percutaneous method has long been employed in Japan. The purpose of this study is to clarify whether the number of needle scars achieved the BCG vaccination differs with the vaccinating physician.

METHODS

A total of 218 babies who were vaccinated at the age of 4 months by different physicians at the Public Health Centres of Katsushika-Ward, Tokyo, were examined at the age of 3 years, in the three-year-old health check-up programme. The BCG vaccination with the multipuncture method generates 18 needle scars at a maximum. We examined each child for how many needle scars after BCG vaccination were visible, with reference to the vaccinating physician.

RESULTS

The mean number of the visible scars was 9.23 (SD 6.11), and significantly smaller (P < 0.01) than that for all 22 Wards (12.18 +/- 5.64) investigated with the same method. The mean number of needle scars of the babies in Katsushika Ward was the third smallest among the 22 Wards and significantly smaller (P < 0.05) than the national average as determined in the nationwide survey conducted in 2000. Significant differences were evident among the 7 physicians performing the vaccination, the best and second best means being 15.26 (SD3.62) and 14.59 (SD3.58) respectively, and significantly larger (P < 0.01) than the means for the 7 physicians. The worst mean was 3.43 (SD4.46), significantly smaller (P < 0.01) than the mean for the 7 physicians.

CONCLUSION

The mean number of needle scars after BCG vaccination of babies significantly differed with the 7 physicians in the present study. Poor technique was presumed responsible for small numbers of scars and technical training is therefore necessary in order to improve the BCG vaccination outcome.

Ets-1 is involved in transcriptional regulation of the chick inducible nitric oxide synthase gene in embryonic ventricular myocytes

In order to elucidate roles of Ets family of transcription factors in transcriptional activation of inducible nitric oxide synthase (iNOS) genes, we analyzed the chick iNOS gene expression in cultured chick embryonic ventricular myocytes (CEVM). Deletional analysis and site-directed mutagenesis demonstrated that both the Ets/PEA3 site (-221 to -216 bp) and the kappaB site (-101 to -93 bp) of the 5'-flanking region of the chick iNOS gene were involved in the maximal activation of the lipopolysaccharide (LPS)-induced expression of the reporter (luciferase) gene, although the proximal kappaB site played the more essential role. Electrophoretic mobility shift assay revealed that LPS augmented the nuclear protein bindings to the Ets/PEA3 as well as kappaB motifs. Ets-1, one of the Ets proteins, was suggested to be bound to the Ets/PEA3 oligonucleotide. By Northern blot analysis, LPS was shown to induce iNOS mRNA in CEVM, along with a preceding increase in the levels of c-ets-1 mRNA. Ets-1 may be involved in the iNOS gene transcription in CEVM, presumably through interacting with the NF-kappaB.

Hypertrophic cardiomyopathy with midventricular obstruction and apical aneurysm: a case report

A 71-year-old woman had hypertrophic cardiomyopathy associated with midventricular obstruction and an apical aneurysm in the left ventricle. She had had abnormal electrocardiograms for more than 30 years and for the past year had been suffering from occasional attacks of dizziness and low systemic blood pressure. Holter 24-h electrocardiographic monitoring revealed ventricular paroxysmal contractions (676/day) with nonsustained ventricular tachycardia. Doppler echocardiography revealed paradoxical jet flow from the apical aneurysm to the left ventricular outflow during early diastole. Magnetic resonance imaging depicted midventricular hypertrophy and a dyskinetic thin apical wall, which were confirmed by angiography. Coronary angiograms showed no narrowing of the major extramural coronary arteries, but there was compression of aberrant coronary arteries apparently feeding the hypertrophic portion of the left ventricular wall. Stress thallium-201 myocardial imaging showed a persistent severe defect in the left ventricular apex. A hemodynamic study revealed low cardiac output and an intraventricular pressure gradient (approximately 90 mmHg) between the left ventricular apical high-pressure chamber and the subaortic low-pressure chamber. The present case represents a rare combination of hypertrophic cardiomyopathy, midventricular obstruction, and an apical aneurysm in an elderly woman. Myocardial ischemia may have played an important role in the genesis of the apical aneurysm.

Left ventricular relaxation abnormality is detectable by analysis of the relaxation time constant in patients with atrial fibrillation

Left ventricular (LV) contractility is constantly changing during atrial fibrillation (AF), which is dependent on the force-interval relationships. However, no information has been available on LV relaxation in patients with both AF and impaired LV systolic function. LV pressure was measured with a catheter-tipped micromanometer and the time constant of isovolumic LV pressure decline (tau(bf)) was calculated with best exponential fitting from more than 10 consecutive beats. Patients with AF (5 with mitral valvular disease, 6 with idiopathic dilated cardiomyopathy, and 1 with no underlying disease) were subdivided into 2 groups: group A, with ejection fraction (EF) <0.5 (n=7); and group B, with EF > or =0.5 (n=5). Linear correlation coefficients (r) between tau and RR2, RR2/RR1, LV peak systolic pressure (peak LVP) were calculated. Although tau did not show a discrepancy between the 2 groups, tau(bf) correlated better with RR2/RR1 only in the group A patients. The relation between tau and peak LVP showed a good correlation with a steep slope (R, Deltatau/Deltapeak LVP) only in the group A patients (accentuated afterload-dependence). R was significantly different between the 2 groups. Thus, a beat-to-beat analysis of tau may be a practical and feasible way for detecting LV relaxation abnormality in patients with AF.

Cloning of hypoxia-inducible factor 1alpha cDNA from chick embryonic ventricular myocytes

Hypoxia-inducible factor 1 (HIF-1) is composed of HIF-1alpha and arylhydrocarbon nuclear receptor translocator (ARNT), which belong to the basic-helix-loop-helix-Per/ARNT/Sim (bHLH-PAS) family of transcription factors. HIF plays key roles in oxygen homeostasis and embryonic cardiovascular development. In this study, we have cloned cDNAs encoding the chick HIF-1alpha from cultured embryonic ventricular myocytes (CEVM) and then examined its expression in various embryonic tissues. The deduced amino acid sequence of the chick HIF-1alpha cDNA showed 79% identity with that of the human HIF-1alpha cDNA. In contrast, sequence homology between the chick HIF-1alpha and endothelial PAS protein 1 (EPAS1), another member of the bHLH-PAS proteins, was only low (49%). HIF-1alpha mRNA was expressed abundantly in CEVM, but scarcely in the liver, which was quite different from expression pattern of EPAS1 mRNA. These data suggest that HIF-1alpha may be involved in embryonic cardiovascular development. HIF-1alpha and EPAS1 may play distinct roles during developmental stages.

Expression of genes encoding vascular endothelial growth factor and its Flk-1 receptor in the chick embryonic heart

Vascular endothelial growth factor (VEGF) is known to play an essential role in embryonic vascular development. The heart is one of the main organs that produce VEGF, but it is still unknown how expression of VEGF gene is regulated in embryonic cardiac myocytes. Thus, we cloned cDNAs encoding VEGF and its receptor (a KDR/flk-1 or Quek1 homologue) from cultured 10-day-old chick embryonic ventricular myocytes (CEVM). Reverse transcription-polymerase chain reaction revealed that the chick VEGF mRNAs consisted of at least four different species corresponding to the isoforms of 190, 166, 146 and 122 amino acids. In the embryonic heart and CEVM, the isoforms of 166 and 122 amino acids were dominant. Northern blot analysis detected an abundance of VEGF mRNA in both the embryonic heart and CEVM, even at the basal state. The levels of VEGF mRNA in CEVM were significantly augmented by forskolin (100 microM), or phorbol 12-myristate, 13-acetate (200 nM) in a time-dependent manner in CEVM. In contrast, the basal levels of VEGF mRNA were attenuated by genistein (100 microM), but not by H89 (100 microM) or bisindolylmaleimide (75 microM). Northern blot analysis also detected the chick flk-1 mRNA in abundance in the embryonic heart, and to a much lesser extent in CEVM. The expression levels of VEGF and flk-1 mRNA species were continuously high in the 6, 8 and 10-day-old chick embryonic hearts. In the 10-day-old embryonic hearts, in situ hybridization confirmed that mRNA encoding VEGF was mainly expressed in ventricular myocytes. In contrast, the flk-1 mRNA was detected in the microvascular endothelial cells, and to a lesser extent in the ventricular myocytes. These data suggest that VEGF is produced in embryonic ventricular myocytes, even at the basal state, and that the levels of VEGF mRNA may be differently regulated by various protein kinases. VEGF produced by the chick embryonic heart may play important roles in embryonic cardiovascular development by acting on surrounding endothelial cells and, possibly, on ventricular myocytes themselves.

Hemodynamic and thermal responses to a 30-minute constant-workload aerobic exercise in middle- or old-aged patients with cardiovascular diseases

The aim of the present investigation was to compare the hemodynamic and thermal responses to a 30-min aerobic exercise between middle- or old-aged patients with normal left ventricular function and those with left ventricular dysfunction. Constant-load sitting ergometer exercise of approximately 90% of the subject's oxygen uptake (VO2) at the anaerobic threshold for 30 min was conducted in 21 patients with left ventricular dysfunction (61+/-10 years, left ventricular ejection fraction (LVEF) 35+/-7%) and 24 patients with normal left ventricular function (59+/-9 years, LVEF 71+/-7%). Heart rate (HR), blood pressure, deep temperatures in the forehead and thigh, and forearm skin blood flow (SkBF) were measured every minute, and cardiac output (CO) and stroke volume (SV) were determined every 10 min with the dye-dilution technique during the exercise. Patients of both groups exhibited a progressive elevation in each temperature and an increase in SkBF during the exercise. Although the VO2 and CO remained stable, almost the same magnitude of decrease in SV as increase in HR was seen after the 10th min of exercise in both groups. The magnitude of the decrease in SV was greater in old-aged than middle-aged patients with left ventricular dysfunction. Thus, the downward drift in SV during a 30-min constant-load aerobic exercise might not be influenced by left ventricular function, but intensified by aging in patients with left ventricular dysfunction.

Lipopolysaccharide augments expression and secretion of vascular endothelial growth factor in rat ventricular myocytes

Vascular endothelial growth factor (VEGF), also known as vascular permeability factor, is highly expressed in the myocardium under various stimuli including hypoxia and ischemia. On the other hand, lipopolysaccharide (LPS) causes systemic inflammatory response syndrome (SIRS), which consists of systemic pathophysiological changes related to vascular hyperpermeability. To test the hypothesis that VEGF is one of the important mediators of SIRS, we examined effects of LPS on the VEGF expression and secretion in cultured neonatal rat ventricular myocytes. LPS (10 microg/ml) rapidly (within 1 h) augmented the levels of VEGF mRNA in these cells. Pharmacological inhibition of nucleic factor-kappaB or tyrosine kinases did not affect the LPS-induced augmentation of VEGF mRNA expression, while these treatments markedly suppressed the up-regulation of inducible nitric oxide synthase (iNOS) expression by LPS. The VEGF concentrations in the conditioned media were also significantly increased by the LPS treatment of 6 h. In conclusion, LPS augments VEGF expression and secretion in rat ventricular myocytes, suggesting that VEGF may be involved in pathogenesis of SIRS. LPS may induce VEGF mRNA through the signaling pathways that are distinct from those responsible for the iNOS induction.

High-resolution imaging of coronary calcifications by intense low-energy fluoroscopic X-ray obtained from synchrotron radiation

PURPOSE

To obtain an intense monochromatic low-energy X-ray from synchrotron radiation (SR) and apply it to detect coronary calcifications.

METHODS AND RESULTS

The SR beam was reflected with a silicon crystal to be expanded (150 mm in height and 80 mm in width) and to be monochromatized at an energy level of 37 keV. The X-ray was intermittently irradiated to obtain dynamic imaging of 30 images/s. Images were recorded by a digital fluorography system. The low-energy X-ray from SR sharply visualized calcification of coronary arteries, while conventional X-ray could not visualize coronary calcification.

CONCLUSION

The intense monochromatic low-energy X-ray from SR is sensitive, has high-resolution for imaging coronary calcification and may serve as a screening method for coronary artery disease.