Identification of a new gibberellin receptor agonist, diphegaractin, by a cell-free chemical screening system

Gibberellin (GA) is a phytohormone that regulates various developmental processes during the plant life cycle. In this study, we identify a new GA agonist, diphegaractin, using a wheat cell-free based drug screening system with grape GA receptor. A GA-dependent interaction assay system using GA receptors and DELLA proteins from Vitis vinifera was constructed using AlphaScreen technology and cell-free produced proteins. From the chemical compound library, diphegaractin was found to enhance the interactions between GA receptors and DELLA proteins from grape in vitro. In grapes, we found that diphegaractin induces elongation of the bunch and increases the sugar concentration of grape berries. Furthermore, diphegaractin shows GA-like activity, including promotion of root elongation in lettuce and Arabidopsis, as well as reducing peel pigmentation and suppressing peel puffing in citrus fruit. To the best of our knowledge, this study is the first to successfully identify a GA receptor agonist showing GA-like activity in agricultural plants using an in vitro molecular-targeted drug screening system.

A target cultivar-specific identification system based on the chromatographic printed array strip method for eight prominent Japanese citrus cultivars

Citrus is a major cultivated crop in Japan, and new cultivars are of great interest in the Japanese and global market. Recently, the infringement of breeders' rights to citrus cultivars bred in Japan has become a problem related to the agricultural product export strategy promoted by the Japanese government. Cultivar identification systems using DNA markers are an effective tool for protecting breeders' rights. Here, a novel target cultivar-specific identification system using the chromatographic printed array strip method was developed for eight prominent Japanese citrus cultivars. A polymorphic InDel fragment specific to each cultivar was explored through the screening of published citrus InDel markers and next-generation sequencing of retrotransposon libraries. The cultivar-specific DNA marker set for each cultivar comprised 1-3 polymorphic InDel fragments in combination with a PCR-positive DNA marker for the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit gene. The DNA markers were detected within 3 hours from DNA extraction to the detection by the C-PAS4 membrane stick following multiplex PCR. The developed system is superior as a convenient, rapid, and cost-effective DNA diagnostic method during inspection. The proposed target cultivar-specific identification system is expected to serve as an efficient tool for the injunction of suspicious registered cultivars, contributing to the protection of breeders' rights.

Evaluation of dural sinus invasion and extension of extra-axial intracranial tumors: The advantages of a high-resolution postcontrast 3-D gradient-echo technique

Objective: To assess the usefulness of a postcontrast 3-D Fourier transform (3DFT) gradient-echo (GRE) technique in dural sinus invasion and extension of extraaxial intracranial tumors in comparison with a conventional spin-echo (SE) technique.

Material and Methods: Fourteen consecutive patients with 15 extra-axial tumors in contiguity with the dural sinus, including 14 meningiomas and 1 adenoid cystic carcinoma, underwent postcontrast T1-weighted SE and GRE MR studies. Detectability of dural sinus invasion and extension was evaluated using two sequences by two neuroradiologists in a blinded manner and compared with surgical results. Quantitative analysis was also performed to calculate the contrast-to-noise ratio (CNR) between lesion and dural sinus on SE and GRE images. The data were analyzed statistically using a matched paired t-test.

Results: In the qualitative evaluation, the detectability of dural sinus invasion in 3DFT-GRE images was superior to that using SE images. The mean CNR for all lesions was 3.86 on SE images and 5.63 on 3DFT-GRE images ( p = 0.03).

Conclusion: For evaluation of dural sinus invasion and the extension of extra-axial tumors, postcontrast 3DFT-GRE MR images were superior to conventional SE images.

Distinguishing imaging features between spinal hyperplastic hematopoietic bone marrow and bone metastasis

BACKGROUND AND PURPOSE

Systematic investigations of the distinguishing imaging features between spinal hyperplastic hematopoietic bone marrow and bone metastasis have not been reported, to our knowledge. The purpose of this study was to determine the distinguishing imaging features of the 2 entities.

MATERIALS AND METHODS

We retrospectively reviewed the radiologic images of 8 consecutive male patients (age range, 52-78 years; mean, 64 years) with suspected spinal metastasis on MR imaging and FDG-PET, which was later confirmed as hyperplastic hematopoietic bone marrow. MR imaging, FDG-PET, CT, and bone scintigraphy images were qualitatively and/or quantitatively evaluated. Imaging findings in 24 patients with spinal metastasis were compared, and differences were statistically analyzed.

RESULTS

All 8 vertebral hyperplastic hematopoietic bone marrow lesions were hypointense on T1- and T2-weighted images; lesions contiguous with the adjacent vertebra were significantly more often seen in hyperplastic hematopoietic bone marrow than in metastasis (P = .035). T2 signal intensity of the lesion was significantly different between the 2 entities (P = .033). FDG-PET showed slightly higher uptake in all hyperplastic hematopoietic bone marrow lesions; their maximum standard uptake value was significantly lower than that of metastatic lesions (P = .037). CT attenuation of hyperplastic hematopoietic bone marrow was equal to or slightly higher than that of adjacent normal-appearing vertebra; the CT appearances of hyperplastic hematopoietic bone marrow and metastasis were significantly different (P < .01). Bone scintigraphy showed normal uptake for all vertebrae with hyperplastic hematopoietic bone marrow; the uptake was significantly different from that of metastasis (P < .01).

CONCLUSIONS

If a lesion was isointense to hyperintense to normal-appearing marrow on MR imaging or had a maximum standard uptake value of >3.6, the lesion was considered metastatic. A normal appearance on CT or bone scintigraphy excluded metastasis.

Comparison of dynamic contrast-enhanced 3T MR and 64-row multidetector CT angiography for the localization of spinal dural arteriovenous fistulas

BACKGROUND AND PURPOSE

For the localization of spinal dural arteriovenous fistulas, it is not determined whether dynamic contrast-enhanced MRA is more reliable than multidetector CTA. The aim of this study was to compare the agreement between intra-arterial DSA, dynamic contrast-enhanced MRA at 3T, and 64-row multidetector CTA for the localization of spinal dural arteriovenous fistulas.

MATERIALS AND METHODS

We enrolled 12 consecutive patients (11 men, 1 woman; age range, 46-83 years; mean, 65 years) who underwent preoperative dynamic contrast-enhanced MRA at 3T and 64-row multidetector CTA. The spinal dural arteriovenous fistula location was confirmed by intra-arterial DSA as the reference standard. Two reviewers independently evaluated the level of the artery feeding the spinal dural arteriovenous fistula on the basis of continuity between the feeder and abnormal spinal vessels on 3T dynamic contrast-enhanced MRA and 64-row multidetector CTA images. Interobserver and intermodality agreement was determined by calculation of the κ coefficient.

RESULTS

On DSA, the vessel feeding the spinal dural arteriovenous fistula was the intercostal artery (7 cases), the lumbar artery (3 cases), and the internal iliac artery or the ascending pharyngeal artery (1 case each). For the fistula level, interobserver agreement was excellent for 3T dynamic contrast-enhanced MRA (κ = 0.97; 95% CI, 0.92-1.00) and very good for 64-row multidetector CTA (κ = 0.84; 95% CI, 0.72-0.96). Intermodality agreement with DSA was good for 3T dynamic contrast-enhanced MRA (κ = 0.78; 95% CI, 0.49-1.00) and moderate for 64-row multidetector CTA (κ = 0.41; 95% CI, 0.020-0.84).

CONCLUSIONS

For the localization of spinal dural arteriovenous fistulas, 3T dynamic contrast-enhanced MRA may be more reliable than 64-row multidetector CTA.

Small Indian mongooses and masked palm civets serve as new reservoirs of Bartonella henselae and potential sources of infection for humans

The prevalence and genetic properties of Bartonella species were investigated in small Indian mongooses and masked palm civets in Japan. Bartonella henselae, the causative agent of cat-scratch disease (CSD) was isolated from 15.9% (10/63) of the mongooses and 2.0% (1/50) of the masked palm civets, respectively. The bacteraemic level ranged from 3.0 × 10¹ to 8.9 × 10³ CFU/mL in mongooses and was 7.0 × 10³ CFU/mL in the masked palm civet. Multispacer typing (MST) analysis based on nine intergenic spacers resulted in the detection of five MST genotypes (MSTs 8, 14, 37, 58 and 59) for the isolates, which grouped in lineage 1 with MST genotypes of isolates from all CSD patients and most of the cats in Japan. It was also found that MST14 from the mongoose strains was the predominant genotype of cat and human strains. This is the first report on the isolation of B. henselae from small Indian mongooses and masked palm civets. The data obtained in the present study suggest that these animals serve as new reservoirs for B. henselae, and may play a role as potential sources of human infection.

Can 3T MR angiography replace DSA for the identification of arteries feeding intracranial meningiomas?

BACKGROUND AND PURPOSE

For identifying the arterial feeders of meningiomas, the usefulness of 3D TOF MRA at 3T has not been systematically investigated. This study was intended to assess whether unenhanced 3D TOF MRA at 3T can replace DSA for the identification of arteries feeding intracranial meningiomas and whether it is useful for assessing their dural attachment.

MATERIALS AND METHODS

Twenty-one consecutive patients with intracranial meningiomas (18 women, 3 men; aged 42-77 years, mean 57 years) underwent DSA, conventional MR imaging, and 3D TOF MRA. Two neuroradiologists independently evaluated the primary and secondary feeders of each tumor on maximum-intensity-projection and source MRA images. They also identified the location of dural attachments based on information from MR imaging/MRA images. Interobserver and intermodality agreement was determined by calculating the κ coefficient.

RESULTS

For the identification of primary and secondary feeders on MRA images, interobserver agreement was very good (κ=0.83; 95% CI, 0.66-1.00) and moderate (κ=0.58; 95% CI, 0.34-0.82) and intermodality agreement (consensus reading of MRA versus DSA findings) was excellent (κ=0.94; 95% CI, 0.84-1.00) and good (κ=0.72; 95% CI, 0.51-0.93), respectively. With respect to the dural attachment of meningiomas, interobserver agreement was very good (κ=0.95; 95% CI, 0.84-1.00). The agreement in the diagnosis between MR imaging/MRA and surgery was excellent (κ=1.00).

CONCLUSIONS

Unenhanced 3D TOF MRA at 3T cannot at present supplant DSA for the identification of the feeding arteries of intracranial meningiomas. This information may be useful for evaluating their dural attachment.

Evaluation of brain and head and neck tumors with 4D contrast-enhanced MR angiography at 3T

BACKGROUND AND PURPOSE

Systematic assessment of brain and head and neck tumors with 4D-CE-MRA at 3T has not been investigated. The purpose of this study was to test the hypothesis that 4D-CE-MRA at 3T can replace DSA in the identification of feeding arteries and tumor stain to plan interventional procedures in hypervascular brain and head and neck tumors.

MATERIALS AND METHODS

Fifteen consecutive patients with brain and head and neck tumors underwent 4D-CE-MRA at 3T and DSA. 4D-CE-MRA combined randomly segmented central k-space ordering, keyhole imaging, SENSE, and half-Fourier imaging. We obtained 30 dynamic scans every 1.9 seconds at an acquired spatial resolution of 0.9 × 0.9 × 1.5 mm; the matrix was 256 × 256. Two independent observers inspected the 4D-CE-MRA images for the main arterial feeders and tumor stain. Interobserver and intermodality agreement was assessed by κ statistics.

RESULTS

For 4D-CE-MRA, the interobserver agreement was fair with respect to the main arterial feeders and very good for the degree of tumor stain (κ = 0.28 and 0.87, respectively). Intermodality agreement was moderate for the main arterial feeders (κ = 0.45) and good for the tumor stain (κ = 0.74).

CONCLUSIONS

Although 4D-CE-MRA may be useful for evaluating tumor stain in hypervascular brain and head and neck tumors, it is not able to replace DSA in planning interventional procedures.

Comparison of 3D FLAIR, 2D FLAIR, and 2D T2-weighted MR imaging of brain stem anatomy

BACKGROUND AND PURPOSE

Although 3D FLAIR imaging visualizes detailed structures of the brain stem, it has not been used to evaluate its normal anatomy. The purpose of this study was to evaluate whether 3D FLAIR images can provide more detailed anatomic information of the brain stem than 2D FLAIR and 2D T2WI.

MATERIALS AND METHODS

We prospectively evaluated MR images in 10 healthy volunteers. 3D and 2D FLAIR images, 2D T2WI, and DTI were obtained on a 3T MR imaging scanner. A VISTA technique was used for 3D FLAIR imaging. White matter tracts and nuclei of the brain stem were determined on 3D and 2D FLAIR images and 2D T2WI by referring to anatomic atlases and DTI color maps. The subjective assessment of the visibility by using a 4-point grading system and the contrast ratio of the structures on 3D and 2D FLAIR images and 2D T2WI were evaluated.

RESULTS

The visibility of the SCP and MCP, DSCP, CST, and CTT was higher on 3D FLAIR images than on 2D T2WI and 2D FLAIR images. The contrast ratio for the CST, SCP, MCP, DSCP, and CTT was significantly different on 3D FLAIR images and 2D T2WI and on 3D FLAIR and 2D FLAIR images; there was no significant difference in contrast ratio for the SCP at the pons on 3D FLAIR and 2D T2WI.

CONCLUSIONS

3D FLAIR images provide detailed anatomic information of the brain stem that cannot be obtained on 2D T2WI and 2D FLAIR images.

Prognostic significance of lymphovascular invasion for patients with stage I non-small cell lung cancer

AIMS

This study retrospectively investigated the clinical significance of lymphovascular invasion (LVI) following a complete resection for stage I non-small cell lung cancer (NSCLC).

METHODS

A total of 226 patients who underwent a complete resection for pathological stage I NSCLC were examined.

RESULTS

Lymphatic invasion was pathologically diagnosed as ly0 in 156 patients, ly1 in 65, and ly2 in 5 patients. The pathological vascular invasion was diagnosed as v0 in 178 patients, v1 in 35, v2 in 10, and v3 in 3 patients. The 5-year survival rate after surgery of the patients with and without lymphatic invasion was 76.8 and 90.6%, respectively. There was a significantly more unfavorable prognosis in patients with lymphatic invasion (p = 0.042). The 5-year survival rate of the patients with vascular invasion was also significantly more unfavorable (67.8%) than that of patients without vascular invasion (90.4%; p = 0.004). LVI was found to significantly correlate with tumor size and the presence of pleural invasion.

CONCLUSION

The LVI of NSCLC is a significant prognostic factor in patients with stage I tumors. In future clinical trials, it is necessary to evaluate the efficacy of adjuvant therapy for the selection of patients according to this criterion.

Quantitative blood flow measurements in gliomas using arterial spin-labeling at 3T: intermodality agreement and inter- and intraobserver reproducibility study

BACKGROUND AND PURPOSE

QUASAR is a particular application of the ASL method and facilitates the user-independent quantification of brain perfusion. The purpose of this study was to assess the intermodality agreement of TBF measurements obtained with ASL and DSC MR imaging and the inter- and intraobserver reproducibility of glioma TBF measurements acquired by ASL at 3T.

MATERIALS AND METHODS

Two observers independently measured TBF in 24 patients with histologically proved glioma. ASL MR imaging with QUASAR and DSC MR imaging were performed on 3T scanners. The observers placed 5 regions of interest in the solid tumor on rCBF maps derived from ASL and DSC MR images and 1 region of interest in the contralateral brain and recorded the measured values. Maximum and average sTBF values were calculated. Intermodality and intra- and interobsever agreement were determined by using 95% Bland-Altman limits of agreement and ICCs.

RESULTS

The intermodality agreement for maximum sTBF was good to excellent on DSC and ASL images; ICCs ranged from 0.718 to 0.884. The 95% limits of agreement ranged from 59.2% to 65.4% of the mean. ICCs for intra- and interobserver agreement for maximum sTBF ranged from 0.843 to 0.850 and from 0.626 to 0.665, respectively. The reproducibility of maximum sTBF measurements obtained by methods was similar.

CONCLUSIONS

In the evaluation of sTBF in gliomas, ASL with QUASAR at 3T yielded measurements and reproducibility similar to those of DSC perfusion MR imaging.

A Study of Surgically Resected Peripheral Non-Small Cell Lung Cancer with a Tumor Diameter of 1.0 CM or Less

Background and Aims:

The widespread use of high resolution computed tomography has increased the number of small peripheral lung cancers. This study reviewed the clinicopathological features of the patients with non-small cell lung cancer (NSCLC) with a tumor diameter of 1 cm or less, in order to explore the adequate management of such small sized lung cancers.

Material and Methods:

This study was a retrospective analysis of consecutive 58 patients (5.3% out of 1095 patients) who underwent a complete resection for a peripheral NSCLC with a diameter of 1.0 cm or less. The clinical features and outcomes were compared with 203 patients with NSCLC with a diameter between 1.1 and 2.0 cm.

Results:

The mean age was 64.5 years and there were 26 males and 32 females. Clinical stage was IA in 57 (98%) and IIIA in 1. Lobectomy was performed in 39 patients, segmentectomy in nine, and nonanatomic wedge resection in ten. Two patients, who underwent systemic lymph node dissection, had mediastinal lymph node metastasis and were diagnosed as pathological stage IIIA; however they did not relapse after surgery. One patient with pathological stage IA papillary adenocarcinoma died due to brain metastases. The five-year overall survival rate and disease free survival rate was 95.0% and 95.3%, respectively. Patients with NSCLC of 1.0 cm or less showed significantly better survival than those with tumors measuring 1.1–2.0 cm in size (p = 0.048).

Discussion:

The indications for avoiding systemic lymph node dissection for operable NSCLC should not be based on the size of the tumor. A small-sized lung cancer might be surgically treated before the tumor enlarges to more than 1.0 cm in size.

Combination of super chilling and high carbon dioxide concentration techniques most effectively to preserve freshness of shell eggs during long-term storage

This study was made to examine the combined effects of stored temperature and carbon dioxide atmosphere on shell egg quality. The shell eggs were packed into polyethylene terephthalate/polyethylene (PET/PE) pouches and stored at 0 degrees C (super chilling), 10 degrees C, and 20 degrees C, respectively for 90 d. The atmospheric carbon dioxide concentration was controlled to obtain the 3 concentration levels of high (about 2.0%), medium (about 0.5%), and low (below 0.01%). Changes in Haugh unit (HU) values, weakening of vitelline membranes, and generation of volatiles were analyzed to evaluate the freshness of shell eggs. Results showed that, compared with the other combinations, the technique of super chilling and high carbon dioxide concentration enabled shell eggs to be most effectively stored for 90 d, based on estimations of the statistical significances of differences in HU values, and on maintaining the initial HU values during storage. In addition, the storage of shell eggs using this combination technique was found to significantly prevent the weakening of the vitelline membrane based on the estimations of numbers of eggs without vitelline membrane breakage when eggs broke, and significantly lowered the incidence of hexanal in the yolk from exposure to the gas chromatographic-mass spectrometric analyses of volatiles. Thus, these results confirmed that the combination of super chilling and high carbon dioxide concentration was the most effective technique for preserving shell eggs during a long term of 90 d compared with other combination techniques.

Comparison of the added value of contrast-enhanced 3D fluid-attenuated inversion recovery and magnetization-prepared rapid acquisition of gradient echo sequences in relation to conventional postcontrast T1-weighted images for the evaluation of leptomeningeal diseases at 3T

BACKGROUND AND PURPOSE

The usefulness of contrast-enhanced 3D T2-FLAIR MR imaging for the evaluation of leptomeningeal diseases has not been systematically investigated. The purpose of this study was to assess the value added by contrast-enhanced 3D T2-FLAIR and MPRAGE sequences to conventional postcontrast T1-weighted images in the evaluation of leptomeningeal diseases. We also undertook in vitro studies in attempts to understand the consequences of our patient study.

MATERIALS AND METHODS

Twelve patients with confirmed leptomeningeal diseases underwent postcontrast T1-weighted, MPRAGE, and 3D T2-FLAIR imaging at 3T. Two radiologists independently assessed the presence of additional information on postcontrast 3D MR images compared with postcontrast T1-weighted images. The effect of different Gd concentrations and flow velocities on the signal intensity on 3D T2-FLAIR images was investigated in vitro.

RESULTS

According to both reviewers, 3D T2-FLAIR images yielded significantly more information than did MPRAGE images (P < .05 and P < .01, respectively). In the in vitro study, 3D T2-FLAIR was more highly sensitive to low Gd concentrations and less sensitive to high Gd concentrations than were T1-weighted or MPRAGE sequences. On 3D T2-FLAIR sequences, at a flow velocity exceeding 1.0 cm/s, the signal intensity of blood-mimicking fluids at concentrations of 0 and 0.1 mmol/L was as low as at 1.3 mmol/L.

CONCLUSIONS

For the depiction of leptomeningeal diseases, postcontrast 3D T2-FLAIR provides more additional information than postcontrast MPRAGE imaging. The superiority of the 3D T2-FLAIR sequence is associated with its high sensitivity to flow.

Thermolabile phenotype of carnitine palmitoyltransferase II variations as a predisposing factor for influenza-associated encephalopathy

To assess the etiology of influenza-associated encephalopathy (IAE), a surveillance effort was conducted during 2000-2003 in South-West Japan. All fatal and handicapped patients except one (4/34 patients) exhibited a disorder of mitochondrial beta-oxidation evoked by the inactivated carnitine palmitoyltransferase II (CPT II) with transiently elevated serum acylcarnitine ratios (C(16:0) + C(18:1))/C(2) > 0.09 during high-grade fever. Analyses of genotypes and allele compositions of CPT II revealed a thermolabile phenotype of compound heterozygotes for [1055T > G/F352C] and [1102G > A/V368I], which shows a higher frequency in IAE patients than healthy volunteers (P < 0.025). The thermolabile phenotype of CPT II variations may be a principal genetic background of IAE in Japanese.

Living-donor liver transplantation for propionic acidaemia

Three patients with the severe form of propionic acidaemia were treated with living-donor liver transplantation (LDLT). The procedure was successful for all patients and the incidence of metabolic decompensation was reduced dramatically even without protein restriction. Biochemically, however, the improvement was not significant and the patients continued to excrete large amounts of propionic acid metabolites. One of the patients experienced a severe acidaemic episode 3 years after transplantation. LDLT has a beneficial effect on the care of severely affected patients since it reduces the risk of metabolic decompensation and improves the quality of life with less strict dietary control. Adequate protein restriction and medication need to be maintained even after successful transplantation.

The mitochondrial acetoacetyl-CoA thiolase (T2) deficiency in Japanese patients: urinary organic acid and blood acylcarnitine profiles under stable conditions have subtle abnormalities in T2-deficient patients with some residual T2 activity

Mitochondrial acetoacetyl-CoA thiolase (T2) deficiency is an inborn error of metabolism affecting isoleucine and ketone bodies in the catabolic process. Mutation analysis and expression analysis of mutant cDNAs have facilitated the division of T2-deficient patients into two groups: those with null mutations in either allele (group 1) and those with mutation(s) retaining some residual T2 activity in at least one of two mutant alleles (group II). Among 5 Japanese T2-deficient patients, GK01 belonged to group I and the other patients (GK19, GK19B, GK30 and GK31) to group II. As we have suggested previously, the severity of ketoacidotic episodes in the group II patients was similar to that in the group I patient. However, the urinary organic acid and blood spot acylcarnitine profiles under stable conditions differed between the two groups. The group I patient had typical profiles for the T2 deficiency. In contrast, in all four patients in group II, tiglylglycine was not or was only faintly detected and the 2-methyl-3-hydroxybutyrate levels were less than the cutoff value. Their tiglylcarnitine levels were within the normal range and 2-methyl-3-hydroxy-, butyrylcarnitine was detected just around the cutoff value in our newborn screening pilot test. Hence, these analyses under stable conditions are not reliable for diagnosing the T2 deficiency in the group II patients. The T2 deficiency (group II) can be misdiagnosed as normal if these analyses are performed under nonepisodic conditions and possibly during the newborn screening for inborn errors of metabolism.

Cerebral gliomas: prospective comparison of multivoxel 2D chemical-shift imaging proton MR spectroscopy, echoplanar perfusion and diffusion-weighted MRI

Developments in MRI have made it possible to use diffusion-weighted MRI, perfusion MRI and proton MR spectroscopy (MRS) to study lesions in the brain. We evaluated whether these techniques provide useful, complementary information for grading gliomas, in comparison with conventional MRI. We studied 17 patients with histologically verified gliomas, adding multivoxel proton MRS, echoplanar diffusion and perfusion MRI the a routine MRI examination. The maximum relative cerebral blood volume (CBV), minimum apparent diffusion coefficient (ADC) and metabolic peak area ratios in proton MRS were calculated in solid parts of tumours on the same slice from each imaging data set. The mean minimum ADC of the 13 high-grade gliomas (0.92+/-0.27 x 10(-3) mm(2)/s) was lower than that of the four low-grade gliomas (1.28+/-0.15 x 10(-3) mm(2)/s) ( P<0.05). Means of maximum choline (Cho)/N-acetylaspartate (NAA), Cho/creatine (Cr), Cho/Cr in normal brain (Cr-n) and minimum NAA/Cr ratios were 5.90+/-2.62, 4.73+/-2.22, 2.66+/-0.68 and 0.40+/-0.06, respectively, in the high-grade gliomas, and 1.65+/-1.37, 1.84+/-1.20, 1.61+/-1.29 and 1.65+/-1.61, respectively, in the low-grade gliomas. Significant differences were found on spectroscopy between the high- and low-grade gliomas ( P<0.05). Mean maximum relative CBV in the high-grade gliomas (6.10+/-3.98) was higher than in the low-grade gliomas (1.74+/-0.57) ( P<0.05). Echoplanar diffusion, perfusion MRI and multivoxel proton MRS can offer diagnostic information, not available with conventional MRI, in the assessment of glioma grade.

Beneficial effect of replacing of angiotensin-converting enzyme inhibitor with angiotensin II antagonist for heart failure patients

OBJECTIVE

Angiotensin-converting enzyme (ACE) inhibitors and beta-blockers improve prognosis inpatients with chronic heart failure. Some patients, however, show little response to combined treatment with an ACE inhibitor and a beta-blocker. In addition, the ACE inhibitor cannot completely suppress angiotensin II production. Our objective was to examine whether replacing the ACE inhibitor with an angiotensin II antagonist can improve the condition of patients with chronic heart failure.

METHODS

In 11 patients with chronic heart failure treated with an ACE inhibitor and a beta-blocker, who have had severe left ventricular dysfunction or high plasma level of natriuretic peptides, left ventricular dimension, and fractional shortening, plasma atrial and brain natriuretic peptide (ANP and BNP) levels were determined before and 3 months after the change of treatment.

RESULTS

After substituting the ACE inhibitor with an angiotensin II antagonist, patients showed New York Heart Association functional class improvement, and significant decrease in left ventricular dimension and BNP.

CONCLUSION

In patients with severe chronic heart failure treated with an ACE inhibitor and a beta-blocker, replacing the ACE inhibitor with an angiotensin II antagonist may be effective. However, this has to be confirmed by an adequately powered randomized controlled study.

Central nervous system lesions in adult T-cell leukaemia: MRI and pathology

Adult T-cell leukaemia (ATL) is a T-cell lymphoid neoplasm caused by human T-cell leukaemia virus type I (HTLV-I). Radiological findings in central nervous system (CNS) involvement have not been well characterised. We reviewed the MRI of 18 patients with ATL who developed new neurological symptoms or signs, and pathology specimens from a 53-year-old woman who died of ATL. MRI findings were divided into three categories: definite, probable, and other abnormal. Definite and probable findings were defined as ATL-related. The characteristic findings were multiple parenchymal masses with or without contrast enhancement adjacent to cerebrospinal fluid (CSF) spaced and the deep grey matter of both cerebral hemispheres, plus leptomeningeal lesion. One patient had both cerebral and spinal cord lesions. Other abnormal findings in eight patients included one case of leukoencephalopathy caused by methotrexate. The histology findings consisted of clusters of tumour cells along perivascular spaces, and scattered infiltration of the parenchyma, with nests of tumour cells. Leptomeningeal infiltration by tumour spread into the parenchyma and secondary degeneration of the neuronal tracts was observed. MRI was useful for detecting CNS invasion by ATL and differentiating it from other abnormalities. The MRI findings seemed to correlate well with the histological changes.

MRI of intracranial germ-cell tumours

Our aim was to review the MRI appearances of primary intracranial germ-cell tumours (GCT). We reviewed the MRI studies of 32 patients: 19 with germinomas, five with teratomas, one with an embryonal carcinoma, five with mixed and two with malignant nongerminomatous GCT. Eleven were in the pineal region, 12 suprasellar, five in the both sites, two in the basal ganglia and two in the corpus callosum. Contrast-enhanced images were available for 27 patients. The solid parts of GCT were nearly isointense with grey matter on both T1- and T2-weighted images. In seven patients with nongerminomatous GCT high-signal components were found on T1-weighted images, representing haemorrhage, high-protein fluid or fat. Cystic components were detected in 17 of 27 patients; eight germinomas and all nine nongerminomatous GCT had cysts. The solid components of germinomas enhanced homogeneously in eight cases and heterogeneously in 10, while all nongerminomatous GCT showed heterogeneous enhancement. MRI features tumours can facilitate correct diagnosis of GCT, including histological subtypes.

Comparison between EPI and HASTE for ultra-fast MR imaging of the human brain

Our purpose was to evaluate and compare the performance of ultra-fast single-shot T2-weighted sequences: echo-planar imaging (EPI) versus half-Fourier single-shot turbo spin-echo (HASTE) and to assess the usefulness of their combined reading. Comparative experiments on a phantom as well as a prospective clinical study in 47 patients were done. Axial images acquired with the following methods were compared: (a) HASTE; (b) segmented HASTE (s-HASTE); (c) single-shot spin-echo EPI (SE-EPI); and (d) gradient-echo EPI (GREEPI). Quantitative and qualitative criteria as well as lesion detectability were analyzed against the "gold standard" fast spin-echo (FSE) sequence. For contrast and contrast-to-noise ratio (CNR) between gray and white matter, GRE-EPI was best. The visibility of small markedly hyperintense lesion was best with HASTE and s-HASTE in the clinical study. Small hyperintense lesions were detected equally well with all four sequences, although all performed significantly worse than FSE. The two HASTE variants were better than the EPIs for the extraaxial lesions. The combination of the GRE-EPI and s-HASTE was judged best, and sometimes superior to the FSE image. HASTE or EPI alone cannot substitute for FSE in the screening evaluation of the brain. However, together, EPI and HASTE could provide comparable diagnostic information to that of FSE because their combination compensates for their individual limitations.

Fatal propionic acidemia in mice lacking propionyl-CoA carboxylase and its rescue by postnatal, liver-specific supplementation via a transgene

Propionic acidemia (PA) is an inborn error of metabolism caused by the genetic deficiency of propionyl-CoA carboxylase (PCC). By disrupting the alpha-subunit gene of PCC, we created a mouse model of PA (PCCA(-/-)), which died in 24-36 h after birth due to accelerated ketoacidosis. A postnatal, liver-specific PCC expression via a transgene in a far lower level than that in wild-type liver, allowed PCCA(-/-) mice to survive the newborn and early infant periods, preventing a lethal fit of ketoacidosis (SAP(+)PCCA(-/-) mice). Interestingly, SAP(+)PCCA(-/-) mice, in which the transgene expression increased after the late infant period, continued to grow normally while mice harboring a persistent low level of PCC died in the late infant period due to severe ketoacidosis, clearly suggesting the requirement of increased PCC supplementation in proportion to the animal growth. Based on these results, we propose a two-step strategy to achieve an efficient PA prevention in human patients: a partial PCC supplementation in the liver during the newborn and early infant periods, followed by a larger amount of supplementation in the late infant period.

Beneficial effect of beta-adrenergic blockade on left ventricular function in haemodialysis patients

Congestive heart failure is a common and serious complication in patients undergoing chronic dialysis. However, there have been no studies on preferential medical therapies to improve left ventricular function in haemodialysis patients. Beta-blocker treatment is known to improve left ventricular function in patients with dilated cardiomyopathy; moreover, plasma levels of noradrenaline and natriuretic peptides are sensitive markers of left ventricular dysfunction. The present study investigated whether beta-blocker treatment could improve left ventricular function in haemodialysis patients with a dilated left ventricle. Our study group comprised 14 haemodialysis patients with a dilated left ventricle, who had undergone maintenance haemodialysis for a mean of 11 years. The following haemodynamic parameters were evaluated before and after 4 months of treatment with the beta-blocker metoprolol: left ventricular dimension at end-systole and end-diastole, and fractional shortening. Plasma levels of noradrenaline, atrial natriuretic peptide and brain natriuretic peptide were also determined. Dry body weight and haemoglobin concentration showed no significant change after compared with before treatment with metoprolol. Heart rate decreased significantly, from 79+/-9 beats/min to 69+/-9 beats/min, but systolic blood pressure remained unchanged. The left ventricular dimension both at end-systole and at end-diastole was decreased, and fractional shortening increased significantly. Plasma levels of noradrenaline did not change significantly, but those of atrial natriuretic peptide and brain natriuretic peptide decreased markedly [from 100+/-89 pg/ml to 46+/-29 pg/ml (P=0.0051) and from 549+/-516 pg/ml to 140+/-128 pg/ml (P=0.0035) respectively]. In conclusion, beta-blocker therapy with metoprolol can markedly attenuate left ventricular remodelling and decrease the plasma levels of natriuretic peptides in haemodialysis patients with a dilated left ventricle.

Relative wall thickness is an independent predictor of left ventricular systolic and diastolic dysfunctions in essential hypertension

The objective of this study was to elucidate the relationship between left ventricular geometry and left ventricular (LV) function in patients with untreated essential hypertension. We evaluated LV systolic and diastolic functions by M-mode echocardiography in 24 normotensive control subjects (NC) and 129 patients with essential hypertension. Patients were divided into four groups according to the relative wall thickness and LV mass index: a normal left ventricle (n=57), a concentric remodeling (n=7), a concentric hypertrophy (n=31), and an eccentric hypertrophy (n=34) group. LV systolic function as measured by midwall fractional shortening (FS) was significantly decreased in both the concentric remodeling and concentric hypertrophy groups; no differences were observed for endocardial FS. LV diastolic function as measured by isovolumic relaxation time (IRT) was also decreased in both the concentric remodeling and concentric hypertrophy groups. In multivariate analysis, relative wall thickness (p<0.0001), end-systolic wall stress (p<0.0001), and systolic blood pressure (p=0.002) were independently associated (r2=0.72) with midwall FS in a model including age, LV mass index, body mass index, diastolic blood pressure and IRT. In addition, relative wall thickness (p=0.0008) and age (p<0.0001) were independently associated (r2=0.31) with IRT in a model including LV mass index, end-systolic wall stress, body mass index, systolic and diastolic blood pressures and midwall FS. We conclude that LV geometry as evaluated by relative wall thickness may provide a further independent stratification of LV systolic and diastolic functions in essential hypertension.

Congenitally corrected transposition of the great arteries in a 65-year-old woman

A 65-year-old Japanese woman was admitted to hospital because of exertional dyspnea. Transthoracic echocardiography showed diffuse hypokinesis of the left-sided ventricular wall, but was not clear enough to provide useful information because of the rotation of the cardiac apex and the presence of lung tissue. Systemic ventriculography showed that the left-sided ventricle with heavy trabeculations was morphologically similar to a normal right ventricle. Magnetic resonance imaging (MRI) clearly revealed corrected transposition of the great arteries. Because this patient had no severe associated cardiac anomalies, systemic ventricular dysfunction is thought to be the major cause of exertional dyspnea. MRI is a useful non-invasive method for the rapid evaluation of cardiac morphology.

Involvement of thioredoxin in the regulation of growth hormone secretion in rat pituitary cell cultures

We report here an examination of the effect of thioredoxin (TRX) on the secretion of growth hormone (GH) from rat anterior pituitary cells in vitro. Treatment of rat pituitary cells with growth hormone-releasing factor (GRF), but not GH, led to a significant increase in intracellular TRX protein levels. GRF, recombinant human TRX (rhTRX), and a combination thereof were all shown to induce immediate GH secretion from pituitary cells, as evidenced by perifusion experiments. RhTRX, but not other reducing agents such as beta-mercaptoethanol and N-acetyl-L-cysteine, augmented GRF-stimulated and -unstimulated GH secretion from rat pituitary cells in a dose-dependent manner. RhTRX did not significantly affect the GH mRNA expression of pituitary cells stimulated in the presence or absence of GRF. In addition, rhTRX-augmented GH secretion was not significantly affected by the presence of cycloheximide. Collectively, these findings suggest that TRX is induced by stimulation with GRF and plays a regulatory role in GH secretion from rat anterior pituitary cells by enhancing the secretion of stored GH, rather than by the synthesis of GH.

Antiarrhythmic drug, cibenzoline, can directly improve the left ventricular diastolic function in patients with hypertrophic cardiomyopathy

The effect of cibenzoline on left ventricular diastolic function was investigated in patients with hypertrophic cardiomyopathy (HCM). Before and 2 h after an oral administration of 200 mg of cibenzoline, echocardiographic, apexcardiographic and gated radionuclide angiographic studies were performed in 12 patients with hypertrophic obstructive cardiomyopathy (HOCM) and 7 with hypertrophic nonobstructive cardiomyopathy (HNCM). After administration of cibenzoline, the left ventricular pressure gradient decreased from 96+/-33 mmHg to 29+/-22 mmHg (<0.0001). Fractional shortening decreased from 53.3+/-7.5 to 45.4+/-6.2% (p=0.0008) in patients with HOCM and from 49.9+/-8.7 to 40.9+/-7.5% (p=0.0039) in patients with HNCM. On the other hand, E-wave velocity increased and A-wave velocity decreased in both groups. The time between the second heart sound and O point was shortened from 253+/-53 to 176+/-21 ms (p<0.0001) in patients with HOCM and from 245+/-54 to 185+/-44 ms (p=0.0050) in patients with HNCM. The time to peak filling rate was shortened from 248+/-79 to 190+/-40 ms (p=0.0072) in patients with HOCM and from 218+/-33 to 163+/-26 ms (p=0.0052) in patients with HNCM. These results indicate that in patients with HCM, cibenzoline suppresses left ventricular systolic function, but can markedly improve left ventricular diastolic dysfunction through its direct action.

Evaluation of the intracranial dural sinuses with a 3D contrast-enhanced MP-RAGE sequence: prospective comparison with 2D-TOF MR venography and digital subtraction angiography

BACKGROUND AND PURPOSE

The diagnosis of dural sinus thrombosis is often difficult because of its variable and nonspecific clinical presentation and the overlapping signal intensities of thrombosis and venous flow on conventional MR images and MR venograms. We compared 3D contrast-enhanced magnetization-prepared rapid gradient-echo (MP-RAGE) sequences with 2D time-of-flight (TOF) MR venography, digital subtraction angiography (DSA), and conventional spin-echo (SE) MR imaging for the assessment of normal and abnormal dural sinuses.

METHODS

In a phantom study, a plastic tube with pulsating flow was used to simulate the intracranial dural sinus. With 3D MP-RAGE, a variety of flow velocities, contrast material concentrations, and angulations between the phantom flow tube and the plane of acquisition were tested to measure their relationship to signal-to-noise ratio (SNR). In a clinical study, 35 patients, including 18 with suspected dural sinus thrombosis, were studied with both MR imaging and DSA. Receiver operating characteristic (ROC) analysis was performed in a blinded fashion using DSA as the reference standard.

RESULTS

With the phantom, the SNR of flow increased with increasing contrast concentration, but was not affected by the angle between the tube and scan slab. There was no relationship between SNR and velocity when the contrast concentration was 1.0 mmol/L or greater. In the clinical study, dural sinus thrombosis as well as the normal anatomy of the dural sinuses were seen better with 3D contrast-enhanced MP-RAGE than with 2D-TOF MR venography. Three-dimensional contrast-enhanced MP-RAGE showed the highest diagnostic confidence on ROC curves in the diagnosis of thrombosis.

CONCLUSION

Three-dimensional contrast-enhanced MP-RAGE is superior to 2D-TOF MR venography and conventional SE MR imaging in the depiction of normal venous structures and the diagnosis of dural sinus thrombosis, and is a potential alternative to DSA.

Hypoglycemic syncope induced by a combination of cibenzoline and angiotensin converting enzyme inhibitor

A 65-year-old Japanese woman with dilated cardiomyopathy, hypothyroidism and refractory sustained ventricular tachycardia experienced a near-death hypoglycemic syncope. The attack seemed to be induced by a high level of serum insulin, probably due to cibenzoline and by concomitant use of an angiotensin converting enzyme inhibitor (ACEI). Additionally, decreased food intake because of a severe toothache may have contributed to the deterioration of her condition. This case warns cardiologists that a combined cibenzoline and ACEI therapy can provoke serious adverse effects such as hypoglycemic syncope in the elderly. Therefore, the possibility of a hypoglycemic attack associated with these drugs should be explained to patients who are in poor condition.

Effect of beta-blockers on circulating levels of inflammatory and anti-inflammatory cytokines in patients with dilated cardiomyopathy

OBJECTIVES

This study was designed to evaluate the beneficial effect of beta-blockers on circulating cytokine levels in patients with dilated cardiomyopathy (DCM).

BACKGROUND

Elevated circulating levels of inflammatory cytokines have been reported in patients with DCM. However, alterations of the levels of inflammatory and anti-inflammatory cytokines in association with beta-blocker therapy are unknown.

METHODS

We studied 32 patients with idiopathic DCM who had been treated with digitalis, diuretics and angiotensin-converting enzyme inhibitors. In addition to this combination therapy, beta-blockers were started in all patients. Serum levels of interleukin (IL)-10, tumor necrosis factor-alpha (TNF-alpha) and soluble TNF receptors (sTNF-R1 and R2) were measured at baseline and 12 weeks after the initiation of beta-blocker therapy. We also measured plasma levels of neurohumoral factors, as well as left ventricular (LV) size and function. Ten age-matched subjects with no cardiac disease served as the control group.

RESULTS

Baseline levels of IL-10, TNF-alpha and sTNF-R2 were significantly higher in patients with DCM than in control subjects (p < 0.05). There was a significant positive correlation between IL-10 and TNF-alpha levels (r = 0.545, p = 0.029). The TNF-alpha/IL-10 ratio correlated well with plasma epinephrine levels (r = 0.677, p = 0.025), and the level of sTNF-R2 was closely related to LV size. Serum levels of IL-10, TNF-alpha and sTNF-R2 were significantly decreased during beta-blocker therapy (p < 0.005).

CONCLUSIONS

Our findings indicate that beta-blockers have an important immunoregulatory role in modifying the dysregulated cytokine network in DCM. This effect of beta-blockers may be partly responsible for the efficacy of therapeutic drugs for heart failure.

Skull base tumors: evaluation with contrast-enhanced MP-RAGE sequence

The purpose of this study is to assess the value of contrast-enhanced MP-RAGE sequence for evaluation of skull base tumors. A total of 36 patients were prospectively evaluated. MP-RAGE showed relatively higher CNRs than other sequences, and there was a significant difference of CNR between the MP-RAGE and contrast T1-weighted SE images when fat tissue was chosen as the background. MP-RAGE was significantly superior to other sequences in the diagnosis of the extent of tumors. Contrast-enhanced MP-RAGE sequence is useful in evaluation of skull base tumors because of its higher contrast, higher spatial resolution, multiplanar capability, and suppression of the fat signal.

Three cases of spinal dural AVF: evaluation with first-pass, gadolinium-enhanced, three-dimensional MR angiography

A first-pass, contrast-enhanced three-dimensional (3D) magnetic resonance (MR) angiography with short acquisition time was performed for three consecutive cases with suspected spinal arteriovenous fistula (AVF). This MR technique demonstrated the feeding arteries and draining veins of the spinal dural AVF, and was very useful for the definite diagnosis of the lesions as a disease with arteriovenous shunt. With this MR technique, we could localize the feeding artery and shunt before conventional angiography. J. Magn. Reson. Imaging 2000;12:949-952.

Coronary spastic angina induced by anticholinesterase medication for myasthenia gravis--a case report

Myasthenia gravis (MG) is characterized by weakness of skeletal muscles because of a decrease in the number of available acetylcholine receptors at neuromuscular junctions. Anticholinesterase medication is widely used to treat MG, but muscarinic side effects sometimes appear and limit the drug usage. To their knowledge, the authors present the first case of coronary spastic angina quite possibly induced by anticholinesterase medication to treat MG. The appearance of coronary spastic angina in the present case is likely mediated through the increase of acethylcholine by anticholinesterase medication.

Time-course changes in left ventricular geometry and function during the development of hypertension in Dahl salt-sensitive rats

Serial changes of left ventricular (LV) geometry and function during the development of hypertension were studied in 50 Dahl salt-resistant (DR) and 88 Dahl salt-sensitive (DS) rats fed an 8% NaCl diet beginning at the age of 6 weeks. Echocardiography at 6, 8, 11, 13, 14, 15, and 18 weeks and in vivo invasive hemodynamic determination at 6, 8, 11, 14, and 18 weeks were performed. After 11 weeks, 33 DS rats were observed for survival analysis. The survival analyses showed that the incidence of death was 57.6% due to heart failure, 27.3% due to stroke, and 15.2% due to sudden death. However, death in the early stages of hypertension was due almost entirely to sudden death or stroke. A high value of relative wall thickness (RWT) and a small end-diastolic dimension were predictive of sudden death and stroke, but LV mass (LVM) was not. Concerning the change in LV geometric patterns, LVM continued to increase to 18 weeks. The RWT increased or remained at a plateau up to 13 weeks, and then progressively decreased after 13 weeks. In contrast, LV function was hyperdynamic between 8 and 11 weeks when compared to DR rats. However, after 13 weeks, all hemodynamic variables of DS rats deteriorated progressively, and all DS rats died of heart failure. Thus, our study indicates that the cardiovascular events associated with the progression of hypertension vary widely according to the stage of hypertension and that RWT is more sensitive in predicting LV conditions than LVM in hypertension.

Dynamic MR imaging of neurohypophyseal germ cell tumors for differential diagnosis of infundibular diseases

PURPOSE

To investigate the MR dynamic patterns of neurohypophyseal germ cell tumors (GCTs) for differential diagnosis of infundibular diseases affecting young people.

MATERIAL AND METHODS

Eleven patients with neurohypophyseal GCTs underwent dynamic MR studies with Tl-weighted spin-echo (SE) or turbo SE techniques. Other infundibular lesions, including adenohypophysitis (n=3), Langerhans' cell histiocytosis (LCH, n=2), and 1 hemangioblastoma from von Hippel-Lindau disease, were also evaluated. Serial images were obtained every 15 s (turbo SE) or 30 s (SE technique) for 240 s after rapid injection of contrast medium. The dynamic patterns were analyzed quantitatively with the contrast medium enhancement ratio.

RESULTS

On dynamic MR images, GCTs typically showed a gradual enhancement increase with a peak between 105 s and 180 s, while two showed a relatively rapid increase. LCH and hemangioblastoma showed a dynamic pattern similar to GCTs, while adenohypophysitis demonstrated a sharp rise and a steeper wash-out with an obvious peak before 90 s.

CONCLUSION

Typical dynamic pattern of GCTs was the gradual enhancement increase without wash-out. Dynamic MR imaging can distinguish GCTs from adenohypophysitis, but is not useful for differentiation from LCH.

Molecular and clinical analysis of Japanese patients with 3-hydroxy-3-methylglutaryl CoA lyase (HL) deficiency

Deficiency of mitochondrial 3-hydroxy-3-methylglutaryl CoA lyase (HL, EC4.1.3.4.) is an autosomal recessive genetic disorder characterized by acute episodes of vomiting, hypotonia, and lethargy in the neonatal period or in infancy. Except in Saudi Arabia, where HL deficiency is the most common organic acidemia, the disorder is quite rare with only 41 cases being reported in the English literature, and only five known cases among Japanese. In this study, we present the results of a molecular analysis of all five Japanese patients together with their clinical phenotypes. Five different mutations in the HL gene were identified: one large deletion, one nonsense mutation, one missense mutation, and two splice mutations. Except for G835A (E279K) with its relatively common occurrence among Japanese, these mutations were unique to each family. The results of expression studies with mutated HL cDNAs confirmed the pathogenicity of these mutations and supported the importance of previously identified functional domains of the HL molecule, i.e., the putative catalytic site or dimerization site. In addition, we identified an alternative splicing event that resulted in the skipping of exons 5 and 6. This alternatively spliced product did not show HL activity and was present in various tissues of normal subjects. Clinically, all patients presented with similar symptoms, except that the timing of the initial presentation varied considerably, from 1 day to 1 year 3 months. In general, patients with null-activity mutations presented earlier in life, whereas those with residual activities presented later.

Left ventricular mass and atrial volume determined by cine magnetic resonance imaging in essential hypertension

To evaluate the relationship between left atrial volume determined by cine magnetic resonance imaging and progression of left ventricular hypertrophy (LVH), left atrial volume and echocardiographic left ventricular mass (LVM) were measured in 30 hypertensive patients (15 without LVH and 15 with LVH) and 10 normotensive control subjects. We also evaluated the effects of antihypertensive therapy on the cardiac chamber volumes and LVM in hypertensive patients. The cardiac chamber volumes and LVM were indexed by body surface area. Although there were no significant differences in left ventricular chamber volumes among the three groups, both maximum and minimum left atrial volume indexes, and the LVM index were greater in hypertensive patients with LVH than in the other two groups. The LVM index was correlated with maximum left atrial volume index (r = 0.74, P < .0001), and minimum left atrial volume index (r = 0.76, P < .0001), respectively. Furthermore, in multivariate models, the LVM index was significantly correlated with maximum left atrial volume index. In hypertensive patients with LVH, both maximum and minimum left atrial volume indexes, and the LVM index significantly reduced after treatment. The percent of changes in maximum left atrial volume index after treatment was significantly correlated with the percent of changes in LVM index after treatment. In conclusion, our data indicate that LVH is an independent determinant of left atrial enlargement, and both LVH and left atrial enlargement may be reversed by some effective therapeutic interventions.

A 25-year-old patient with low cardiac risk factors having a combination of variant angina and severe coronary arterial lesions--a case report

A 25-year-old man with low cardiac risks underwent coronary arteriography because of chest pain at rest. His only risk factors for coronary artery disease was smoking. Both right and left coronary arteries were ectatic and the left anterior descending artery was obstructed. In the acetylcholine provocation test, the left circumflex coronary artery showed severe constriction. Thus, this patient was diagnosed as having a combination of variant angina and occlusive coronary artery disease.

Transient U wave inversion during treadmill exercise testing in patients with left anterior descending coronary artery disease

The transient U wave inversion during exercise is specific for detecting left anterior descending coronary artery (LAD) disease. In a homogeneous patient group restricted to LAD disease, however, the significance of the electrocardiographic finding has not yet been clarified. Thus, clinical characteristics in patients with angiographically documented one-vessel disease of the LAD and exercise-induced U wave inversion were delineated. Symptom-limited treadmill exercise testing was performed in 60 patients (43 men, 17 women; mean age 64 +/- 8 years) with angina pectoris whose culprit lesion was located only in the LAD. U wave polarity and amplitude were determined before, during, and after exercise with the P-Q segment as the isoelectric line. Exercise-induced transient U wave inversion was defined as positive when there was a discrete negative deflection > or = 0.05 mV within the T-P segment. Of all patients, 16 (27%) had exercise-induced U wave inversion. There were no differences in age, male gender, antianginal medication use, and coronary angiographic data between the two patients groups: patients with and without U wave inversion. Heart rate and double product of heart rate and systemic systolic blood pressure at peak exercise were also similar. Prevalence of abnormal exercise-induced S-T segment shift was 94% (15 of 16 patients) and 61% (27 of 44 patients) of patients with and without U wave inversion, respectively. The difference was statistically significant (p = 0.02). Among patients with exercise-induced S-T segment shift, the proportion of patients with S-T segment elevation to all the patients was larger in patients with U wave inversion than in patients without U wave inversion [3 (20%) of 15 patients vs 0 (0%) of 27 patients, p = 0.03)]. In conclusion, the exercise-induced U wave inversion in patients with one-vessel disease of the LAD indicates the severe degree of myocardial ischemia induced in the territory perfused by the LAD. However, the electrocardiographic finding does not appear to have independent significance since it closely correlates with the presence of S-T segment shift.

Accumulation of N-acetyl-L-aspartate in the brain of the tremor rat, a mutant exhibiting absence-like seizure and spongiform degeneration in the central nervous system

The tremor rat is a mutant that exhibits absence-like seizure and spongiform degeneration in the CNS. By positional cloning, a genomic deletion was found within the critical region in which the aspartoacylase gene is located. Accordingly, no aspartoacylase expression was detected in any of the tissues examined, and abnormal accumulation of N-acetyl-L-aspartate (NAA) was shown in the mutant brain, in correlation with the severity of the vacuole formation. Therefore, the tremor rat may be regarded as a suitable animal model of human Canavan disease, characterized by spongy leukodystrophy that is caused by aspartoacylase deficiency. Interestingly, direct injection of NAA into normal rat cerebroventricle induced 4- to 10-Hz polyspikes or spikewave-like complexes in cortical and hippocampal EEG, concomitantly with behavior characterized by sudden immobility and staring. These results suggested that accumulated NAA in the CNS would induce neuroexcitation and neurodegeneration directly or indirectly.