The effectiveness of strict low-density lipoprotein cholesterol management in secondary prevention of Japanese patients

Background

In Japanese guidelines, target value of low-density lipoprotein cholesterol (LDL-C) <100mg/dL is recommended as standard management for secondary prevention of coronary artery disease. On the other hand, the guidelines also state that LDL-C targeting <70mg/dL should be considered in high-risk patients. However, the effectiveness of strict LDL-C management in the prevention of long-term coronary event recurrence in Japanese patients remains unclear.

Purpose

The purpose of the present study was to evaluate whether the strict management of LDL-C targeting <70 mg/dL was effective to prevent recurrence of acute coronary syndrome (ACS) than standard management in patients with previous percutaneous coronary intervention (PCI).

Methods

From January 2007 to August 2020, we performed coronary angiography in 359 patients with previous PCI who were suspected of having signs of recurrent cardiac ischemia. Patients were stratified into three groups according to achieved LDL-C value; <70mg/dL (n=57), 70 to <100mg/dL (n=135) and ≥100mg/dL (n=167). In addition, patients who had previous ACS and/or diabetes mellitus were defined as high-risk group, and sub-analysis by their achieved LDL-C values was performed in high-risk group and non-high-risk group. Endpoint was recurrence of ACS. Moreover, risk factors associated with recurrent-ACS were examined in patients with LDL-C <100 mg/dL.

Results

After follow-up (median 6.1 years), 99 patients (28%) had recurrent-ACS. Recurrent-ACS was significantly lower in patients with LDL-C <70mg/dL than LDL-C 70 to <100mg/dL and LDL-C ≥100mg/dL (p<0.01 and p<0.001, respectively). In sub-analysis, high-risk group with LDL-C <70 mg/dL had lower incidence of recurrent-ACS than LDL-C 70 to <100 mg/dL (p=0.03). Similar tendency was found in non-high-risk group (p=0.08). There was no difference of recurrent-ACS between high-risk group and non-high-risk group in patients with LDL-C <70mg/dL (p=0.41). Moreover, in patients with achieved LDL-C <100mg/dL (n=192), multivariate analysis identified that LDL-C (HR: 1.032, p<0.01) and HbA1c (HR: 1.330, p<0.01) were independent predictors of recurrent-ACS. In these patients, whether or not they were in the high-risk group was not a significant predictor (p=0.61).

Conclusions

Strict management of LDL-C targeting <70 mg/dL should be considered for a wider range of Japanese patients as well as for Westerners to prevent recurrence of ACS in secondary prevention.

Funding Acknowledgement

Type of funding sources: None. Probability of freedom from ACS

Effectiveness of more strict managements after achievement of standard target value of low-density lipoprotein cholesterol in secondary prevention of Japanese patients

Background

In secondary prevention of coronary artery disease, target value of low-density lipoprotein cholesterol (LDL-C) <100 mg/dL is recommended as standard management in Japanese guideline. The guideline also stated that strict management of LDL-C targeting <70 mg/dL is considered in some high risk patients. However, in Japanese patients, effectiveness of more strict management of LDL-C lowering therapy for prevention of long-term cardiovascular events remains unclear.

Purpose

The purpose of the present study was to evaluate whether the strict management of LDL-C targeting <70 mg/dL was effective to prevent recurrence of long-term coronary events than standard management in patients with previous percutaneous coronary intervention (PCI).

Methods

We investigated 344 patients with previous PCI who underwent late coronary angiography to examine recurrence of cardiac ischemia beyond the early phase of restenosis from January 2007 to August 2019. Patients were stratified into three groups according to achieved LDL-C value; LDL-C <70mg/dL (n=53), 70 to <100mg/dL (n=130) and ≥100mg/dL (n=161). Endpoints of this study were recurrence of cardiac ischemia presenting as acute coronary syndrome (recurrence-ACS) and any late coronary revascularization.

Results

During average 7.1 years follow-up, 200 patients (58%) underwent any late coronary revascularization. In 94 of those patients, recurrence-ACS was observed. The incidence of recurrence-ACS was significantly lower in patients with achieved LDL-C <70mg/dL than in those with LDL-C 70 to <100mg/dL and LDL-C ≥100mg/dL (p=0.009 and p=0.001, respectively), however, there was no difference between patients with LDL-C 70 to <100mg/dL and LDL-C ≥100mg/dL (p=0.140). Any late revascularization was significantly lower in patients with achieved LDL-C <70mg/dL and in those with LDL-C 70 to <100mg/dL than in those with LDL-C ≥100mg/dL (p=0.002 and p<0.001, respectively), however, no difference was found between patients with LDL-C <70mg/dL and LDL-C 70 to <100mg/dL (p=0.119). Moreover, in patients with achieved LDL-C <100mg/dL (n=183), multivariate analysis identified that LDL-C (HR 1.035, p=0.007) and HbA1c (HR 1.338, p=0.001) were independent predictors of recurrence-ACS. In contrast, only using statins (HR 0.461, p=0.009) was an independent predictor of recurrence-ACS in patients with achieved LDL-C ≥100mg/dL.

Conclusions

LDL-C was the important residual risk of recurrence-ACS even after recommended standard LDL-C lowering management had been achieved. More strict management of LDL-C targeting to <70mg/dL should be considered to prevent recurrence-ACS for wider range of Japanese patients in secondary prevention.

Incidence of late coronary events

Funding Acknowledgement

Type of funding source: None

P1520 Aortic flow reversal caused by aortic regurgitation deteriorates renal function

Background

Chronic kidney disease is a growing public health problem. Renal dysfunction is known as a strong risk factor for cardiovascular disease and end-stage renal failure. The presence of pan-diastolic flow reversal in the abdominal aorta is a very specific sign of severe aortic regurgitation (AR). A higher aortic reverse/forward flow ratio is associated with lower intrarenal forward flow. However, the influence of AR on renal function has been poorly understood. We hypothesized that the aortic flow reversal reduces the renal artery forward flow and accordingly leads to renal dysfunction in patients with severe AR.

Methods

The study consisted of 21 consecutive patients (mean age 69 ± 11 years) with severe AR who underwent aortic valve replacement (AVR). We compared echocardiographic indices and the glomerular filtration rate (GFR) before and 603 ± 541 days after AVR.

Results

Blood pressure was 122 ± 16/54 ± 8 mmHg before AVR and 123 ± 16/76 ± 11 mmHg after AVR. After AVR, left ventricular (LV) end-diastolic dimension decreased from 57 ± 9 to 44 ± 5 mm and LV ejection fraction increased from 58 ± 12 to 60 ± 11 %. Estimated GFR significantly increased from 62.9 ± 18.9 to 71.8 ± 18.1 mL/min per 1.73 m2 after AVR (p = 0.003).

Conclusions An increase in aortic flow reversal caused by severe AR reduces forward flow into the kidney and thereby deteriorates renal function. This study demonstrated a key mediating role of central hemodynamic factors, particularly an exaggerated aortic flow reversal in renal dysfunction and severe AR.

P642What is the most important residual risk after achievement of appropriate low-density lipoprotein cholesterol lowering therapy in secondary prevention of Japanese patients?

Background

In secondary prevention of coronary artery disease, target value of low-density lipoprotein cholesterol (LDL-C) <100mg/dL with using statins is recommended as standard therapy in Japanese guideline. However, impact of residual risks after achievement of standard LDL-C lowering therapy was not fully examined. Furthermore, there is little information whether more strict management of LDL-C lowering is effective to prevent long-term cardiovascular events than standard management.

Purpose

The purpose of this study was to evaluate the relationship between residual risks after achievement of standard LDL-C lowering therapy and long-term coronary events in secondary prevention of Japanese patients.

Methods

From January 2007 to August 2018, 333 patients with previous percutaneous coronary intervention underwent late coronary angiography to examine recurrence of cardiac ischemia beyond the early phase of restenosis. We defined appropriate LDL-C lowering therapy as achieved LDL-C <100mg/dL with using statins. Patients whose achieved LDL-C was <100mg/dL with using statins were classified as Appropriate-group (n=139), and patients who were not using statins or whose achieved LDL-C was ≥100mg/dL were classified as Inappropriate-group (n=194). Endpoints of the study were recurrence of cardiac ischemia as acute coronary syndrome (recurrence-ACS) and any late coronary revascularization.

Results

During average 7.1 years follow-up, 195 patients (59%) underwent any late coronary revascularization. In 91 of those patients, clinical presentation of recurrence-ACS was observed. Kaplan-Meier curve analysis revealed that the incidence of recurrence-ACS and any late coronary revascularization were significantly lower in Appropriate-group than in Inappropriate-group (p=0.017 and p<0.001, respectively). In Appropriate-group, recurrence-ACS was significantly lower in patients with achieved LDL-C <70mg/dL than in those with LDL-C 70 to <100mg/dL (p=0.042), however, any late revascularization was not different between the two groups. On the other hand, in Inappropriate-group, recurrence-ACS was significantly lower in patients with using statins than in those without using statins (p=0.038), and any late revascularization was less frequent in patients with achieved LDL-C <100mg/dL than in those with LDL-C ≥100mg/dL (p=0.035). Moreover, multivariate analysis identified that only LDL-C was an independent predictor of recurrence-ACS in Appropriate-group (HR: 1.047, p=0.006), in contrast, LDL-C (HR: 1.008, p=0.020), using statins (HR: 0.555, p=0.034) and triglyceride (HR: 1.003, p=0.038) were independent predictors of recurrence-ACS in Inappropriate-group.

Conclusions

LDL-C was the most important residual risk of recurrence-ACS even after recommended standard therapy has been achieved. More strict management of LDL-C targeting to <70mg/dL should be considered in secondary prevention of Japanese patients.

Recurrent Spindle Cell Carcinoma Shows Features of Mesenchymal Stem Cells

This study investigated a case of spindle cell carcinoma (SpCC) in tongue pathological lesions. The patient experienced a local recurrence and distant metastasis after surgical intervention. Although standard chemotherapy was administered, a granulomatous mass continued to develop. This aggressive growth led to survival of the tumor. Secondary debulking surgery was performed to improve the patient's quality of life at the request of the patient. Using a tissue sample derived from the secondary debulking surgery, we performed an analysis of the tumor's cell surface antigens, differentiation potential, metastatic ability, and inhibition potential by anticancer reagents. In vitro analysis revealed that the cell population grown under adherent culture conditions expressed the mesenchymal stem cell (MSC) markers CD73, CD90, and CD105. The cell line established from this SpCC contained colony-forming unit fibroblasts (CFU-Fs) and exhibited multipotent differentiation into several mesenchymal lineages, including bone, cartilage, and fat. The SpCC cells also displayed vigorous mobilization. These characteristics suggested that they had the differentiation potential of mesenchymal cells, especially MSCs, rather than that of epithelial cells. The surgical specimen analyzed in this study resisted the molecular target reagent cetuximab, which is an epidermal growth factor receptor inhibitor. This clinical insight revealed that chemotherapy-resistant SpCC cells have different characteristics compared to most other cancer cells, which are sensitive to cetuximab. Our cell death assay revealed that SpCC cell death was induced by the anticancer drug imatinib, which is known to inhibit protein tyrosine kinase activity of ABL, platelet-derived growth factor receptor α (PDGFRα), and KIT. Here, we report recurrent SpCC with characteristics of MSCs and potential for treatment with imatinib.

Combination of low-dose total skin electron beam therapy and subsequent localized skin electron beam therapy as a therapeutic option for advanced-stage mycosis fungoides

Electron beam therapy (EBT) is an established treatment for mycosis fungoides (MF), but evidence for the use of EBT in advanced cutaneous conditions is limited, and optimal scheduling of the regimen for such conditions remains unclear. We report the case of a 44-year-old woman diagnosed with MF with widespread cutaneous lesions, including multiple huge tumours in the craniofacial area. Low-dose total skin (TS)EBT and subsequent localized skin (LS)EBT achieved striking improvements in eruptions. Oral etretinate was also administered during therapy. Our experience implies that combined TSEBT and LSEBT may be worth attempting when a patient presents with both widespread lesions and prominent tumours, even when the tumours are extremely large.

Thermo-Sensitive Release Behavior of 5-Fluorouracil from Chitosan-Gel Microspheres Coated with Lipid Multilayers

In order to provide a device that would release anticancer drugs in response to temperature, chitosan microspheres with immobilized 1-[N-(5- aminopentyl)urea]-5-fluorouracil (Ap-5FU) and coated with dipalmitoyl phosphatidyl choline (DPPC) multilayers were prepared. The chitosan-DPPC- chitosan microspheres were prepared by coating chitosan-DPPC microspheres with polyelectrolyte complex membrane of chitosan. Good distributive stability of microspheres in aqueous solution was achieved with the DPPC multilayers coating. When chitosan was crosslinked with glutaraldehyde, Ap-5FU was si multaneously immobilized to the microspheres by means of Schiffs base forma tion. In physiological saline media, free 5FU released from the microspheres was detected, but the 5FU derivative was not. The release rate of 5 FU from the microspheres was decreased by coating with DPPC multilayers, and further depressed by the formation of polyelectrolyte complex membrane. The thermo- sensitive release behavior of 5FU from chitosan-DPPC microspheres and chitosan-DPPC-chitosan microspheres was observed in vitro across the phase transition temperature ( T m) of the DPPC multilayer (41.4 ° C).

Antitumor Activity of Chitosan and Chitin Immobilized 5-Fluorouracils through Hexamethylene Spacers via Carbamoyl Bonds

To provide a macromolecular prodrug of 5-fluorouracil (5FU) with reduced side-effects, an affinity for tumor cells and exhibiting the high antitu mor activity, the covalent attachment of 5FU to chitosan and chitin through hexamethylene spacers via carbamoyl bonds was carried out. In vivo testing against p-388 lyphocytic leukemia in female CDF1 mice by intraperitoneal in jection ( i.p.) and the in vivo growth-inhibitory effect on Meth-A fibrosarcoma in SPF-C3H/He mice by subcutaneous injection (s.c.)/intravenous injection (i.v.) were evaluated. The effects of the degree of polymerization of chitosan and the degree of 5FU substitution per glucosamine unit on the prolongation of life were investigated. The chitosan-5FU and chitin-5FU conjugates exhibited high survival effects and chitosan-5FU conjugate showed significant growth- inhibitory effect on Meth-A fibrosarcoma. These chitosan-5FU and chitin-5FU conjugates did not display any acute toxicity in the 800 mg/kg dose range.

Acquired dermal melanocytosis of the face and extremities

Acquired dermal melanocytosis (ADM) is a relatively rare, but well-described disease among adolescent to middle-aged East Asian women, particularly those of Japanese and Chinese descent. Clinically, ADM manifests as multiple punctate and greyish-brown pigmented areas 1-3 mm in diameter occurring on both sides of the forehead and zygomatic region. The subtype of ADM affecting the face and extremities is extremely rare even in East Asian women. We describe three patients with ADM of the face and extremities (ADMFE) and their characteristic clinical features. All patients were Japanese women, and showed multiple greyish-brown pigmentations on both nasal wings and on the extensor surface of the extremities. We found that the clinical features were strikingly uniform, and that a pigmented lesion on the nasal wing can be an important clue to distinguish ADMFE from other hyperpigmented diseases of the hands and feet. One patient was treated with Q-switched ruby laser with excellent outcome. Increased awareness of ADMFE can lead to earlier diagnosis and potential treatment.

Translational initiation regulated by ATM in dendritic cells development

Ataxia telangiectasia mutated (ATM) protein has been implicated in multiple pathways such as DNA repair, cell cycle checkpoint, cell growth, development, and stem cell renewal. In this study, we demonstrate evidence that ATM is involved in granulocyte macrophage colony-stimulating factor (GM-CSF)-induced dendritic cell (DC) development from bone marrow (BM) cells. Inactivation of ATM protein results in decreased BM proliferation, leading to reduced DC development and their activity for T cell activation. Expression of Jak2, STAT5, and mTOR is suppressed in both wild-type and ATM-null BM prior to GM-CSF stimulation. Activation of those proteins is delayed and prolonged hypophosphorylation of 4EBP1 is observed in ATM-null BM when treated with GM-CSF, although Erk and p38 are similarly expressed and activated in both wild-type and ATM-null BM cell types. Akt is also suppressed in wild-type BM, and transduction of constitutively active Akt or STAT5 in ATM-null BM restores DC development. Together, these results illustrate that ATM deficiency causes impaired initiation of protein translation in BM, leading to immature development of DC.

Three-electron interatomic Coulombic decay from the inner-valence double-vacancy states in NeAr

We have unambiguously identified interatomic Coulombic decay in NeAr from the inner-valence double-vacancy state Ne-Ar(2+)(3s(-2)) to outer-valence triple-vacancy states Ne(+)(2p(-1))-Ar(2+)(3p(-2)) by momentum-resolved electron-ion multicoincidence. This is the first observation of interatomic Coulombic decay where three electrons (3e) participate. The results suggest that this 3e interatomic Coulombic decay is significantly faster than other competing processes like fluorescence decay and charge transfer via curve crossing.

Experimental observation of rotational Doppler broadening in a molecular system

The first experimental evidence of rotational Doppler broadening in photoelectron spectra, reported here, show good agreement with recently described theoretical predictions. The dependence of the broadening on temperature and photoelectron kinetic energy is quantitatively predicted by the theory. The experiments verify that the rotational contributions to the linewidth are comparable to those from translational Doppler broadening and must be considered in the analysis of high-resolution photoelectron spectra. A classical model accounting for this newly observed effect is presented.

Projection of Si 1s photoexcited orbitals into resonant Auger electron spectra in KLL decays of Si(CH3)4 and SiF4

Spectator resonant KL(23)L(23) Auger electron spectra have been measured in the Si 1s photoexcitation region of Si(CH(3))(4) using monochromatized undulator radiation combined with a hemispherical electron spectrometer. The broad peak with high intensity in a total ion yield spectrum, coming mainly from excitation of a 1s electron into the 6t(2) vacant orbital, induces a spectator Auger decay in which the excited electron remains in its excited orbital. The component on the higher energy side of this peak through 1s excitation into a Rydberg orbital produces resonant Auger decays in which the excited Rydberg electron moves into a slightly higher Rydberg orbital, or is partly shaken up to a significantly higher Rydberg orbital. These findings of Si(CH(3))(4) indicate a clear contrast to those for SiF(4), in which the 1s excitation into a Rydberg orbital induces a shake-down phenomenon as well as a shake-up one. The results of these molecules exhibit a clear splitting effect among excited orbitals which are smeared out by overlapping due to lifetime widths and due to densely populated levels in the 1s electron excitation spectrum. This is consistent with the calculation on photoexcitation within the framework of density functional theory.

Electron-transfer-mediated decay and interatomic Coulombic decay from the triply ionized states in argon dimers

We report the first observation of electron-transfer-mediated decay (ETMD) and interatomic Coulombic decay (ICD) from the triply charged states with an inner-valence vacancy, using the Ar dimer as an example. These ETMD and ICD processes, which lead to fragmentation of Ar(3+)-Ar into Ar(2+)-Ar(2+) and Ar(3+)-Ar+, respectively, are unambiguously identified by electron-ion-ion coincidence spectroscopy in which the kinetic energy of the ETMD or ICD electron and the kinetic energy release between the two fragment ions are measured in coincidence.

A Japanese-specific recurrent mutation and a novel splice site mutation in the LAMC2 gene identified in two Japanese families with Herlitz junctional epidermolysis bullosa

BACKGROUND

Herlitz junctional epidermolysis bullosa (H-JEB) is an extremely rare genodermatosis characterized by lethality owing to severe blister formation. We report two unrelated Japanese patients with H-JEB. Genetic analyses detected a single nonsense mutation on the LAMC2 gene in these two patients.

AIM

To identify the mutation involved and describe the first reported Japanese recurrent mutation in the LAMC2 gene.

METHODS

Direct sequencing was performed of DNA from either peripheral blood or fetal cells in amniotic fluid. Reverse transcriptase PCR was used to confirm that an aberrant transcript resulted from the splice site mutation. A haplotype analysis was performed to define the origin of the recurrent mutation.

RESULTS

Both patients had blisters and erosions on the trunk and limbs at birth, with nail dystrophy. Patient 1 died as a result of sepsis at 30 weeks of age, and patient 2 died as a result of disseminated intravascular coagulation at 20 weeks of age. Mutation analysis of the LAMC2 gene revealed that patient 1 was compound heterozygous for a nonsense mutation (p.Cys553X) and a novel splice site mutation (c.2868+1delG), and patient 2 was a homozygous for p.Cys553X. Prenatal diagnosis performed during a subsequent pregnancy in family 2 revealed that this second child was heterozygous for p.Cys553X, and was thus not affected. Haplotype analysis suggested that a p.Cys553X allele derived from the same origin had been independently inherited by these two unrelated families.

CONCLUSIONS

p.Cys553X in the LAMC2 gene may be a Japanese-specific recurrent mutation as a result of a founder effect, and it may therefore be useful for initial screening in the mutation analysis of H-JEB.

Anisotropy and Corotation of Galactic Cosmic Rays

The intensity of Galactic cosmic rays is nearly isotropic because of the influence of magnetic fields in the Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using the large data sample of the Tibet Air Shower Arrays. Besides revealing finer details of the known anisotropies, a new component of Galactic cosmic ray anisotropy in sidereal time is uncovered around the Cygnus region direction. For cosmic-ray energies up to a few hundred TeV, all components of anisotropies fade away, showing a corotation of Galactic cosmic rays with the local Galactic magnetic environment. These results have broad implications for a comprehensive understanding of cosmic rays, supernovae, magnetic fields, and heliospheric and Galactic dynamic environments.

Neuroradiological Analysis of 23 Cases of Basilar Artery Fenestration Based on 2280 Cases of MR Angiographies

SUMMARY

Basilar artery (BA) fenestrations are the most frequently observed variant of the cerebral arteries. We examined the magnetic resonance (MR) angiographic incidence, location, characteristic configuration of BA fenestration and associated vascular disease. From April 2004 to September 2004, a total of 2280 cranial MR angiographies were performed at our institution. Twenty-three BA fenestrations (1.0%) were detected on MRA. There were 13 males and ten females in this group and mean age was 57.6 years old. Three cases of these fenestration group are suffered with atherothrombic infarction in the territory of vertebro-basilar system. Seven of 23 cases (30%) were associated with intracranial aneurysm. Of those four cases, aneurysms were located at anterior circulation. Of those three cases, the aneurysms were associated with BA fenestration. Since saccular aneurysms are reported to arise frequently at BA fenestration, knowledge and recognition of fenestration are useful and important in the interpretation of cerebral MR angiography.

Overexpression of aurora kinase A in mouse mammary epithelium induces genetic instability preceding mammary tumor formation

Aurora-A/STK15/BTAK, which encodes a centrosome-associated kinase, is amplified and overexpressed in multiple types of human tumors, including breast cancer. However, the causal relationship between overexpression of Aurora-A and tumorigenesis has not been fully established due to contradictory data obtained from different experimental systems. To investigate this, we generated a mouse strain that carries an MMTV-Aurora-A transgene. We showed that all the MMTV-Aurora-A mice displayed enhanced branch morphogenesis in the mammary gland and about 40% developed mammary tumors at 20 months of age. The tumor incidence was significantly increased in a p53(+/-) mutation background with about 70% MMTV-Aurora-A;p53(+/-) animals developed tumors at 18 months of age. Of note, overexpression of Aurora-A led to genetic instability, characterized by centrosome amplification, chromosome tetraploidization and premature sister chromatid segregation, at stages prior to tumor formation. Most notably, the severe chromosomal abnormality did not cause cell death owing to the activation of AKT pathway, including elevated levels of phosphorylated AKT and mammalian target of rapamycin, and nuclear accumulation of cyclin D1, which enabled continuous proliferation of the tetraploid cells. These data establish Aurora-A as an oncogene that causes malignant transformation through inducing genetic instability and activating oncogenic pathways such as AKT and its downstream signaling.

Secretion of bacterial xenobiotic-degrading enzymes from transgenic plants by an apoplastic expressional system: an applicability for phytoremediation

In search of an effective method for phytoremediation of wastewater contaminated with organic compounds, we investigated the application of an apoplastic expressional system that secretes useful bacterial enzymes from transgenic plants into hydroponic media through the addition of a targeting signal. We constructed transgenic Arabidopsis expressing the aromatic-cleaving extradiol dioxygenase (DbfB), which degrades 2,3-dihydroxybiphenyl (2,3-DHB), and transgenic tobacco expressing haloalkane dehalogenase (DhaA), which catalyzes hydrolytic dechlorination of 1-chlorobutane (1-CB). Although crude leaf extracts of transgenic plants expressing cytoplasm-targeted degradative enzymes showed higher activity than did those from transgenic plants expressing apoplast-targeted enzymes, the hydroponic media of the latter showed 23.2 times (DbfB) and 76.4 times (DhaA) higher activity than plants containing the cytoplasm-targeted enzymes. Addition of crystalline 2,3-DHB to 100 mL of the hydroponic medium of transgenic or wild-type seedlings revealed that only medium from the transgenic Arabidopsis expressing apoplast-targeted DbfB showed rapid ring cleavage of 2,3-DHB. Transgenic tobacco expressing apoplast-targeted DhaA also resulted in the accumulation of the dehalogenation product 1-butanol in the hydroponic medium and showed a higher tolerance to 1-CB than wild-type or transgenic plants expressing cytoplasm-targeted DhaA. These results demonstrate the usefulness of the apoplastic expression of bacterial recombinant proteins in phytoremediation.

Observation by an air-shower array in Tibet of the multi-TeV cosmic-ray anisotropy due to terrestrial orbital motion around the Sun

We report on the solar diurnal variation of the galactic cosmic-ray intensity observed by the Tibet III air shower array during the period from 1999 to 2003. In the higher-energy event samples (12 and 6.2 TeV), the variations are fairly consistent with the Compton-Getting anisotropy due to the terrestrial orbital motion around the Sun, while the variation in the lower-energy event sample (4.0 TeV) is inconsistent with this anisotropy. This suggests an additional anisotropy superposed at the multi-TeV energies, e.g., the solar modulation effect. This is the highest-precision measurement of the Compton-Getting anisotropy ever made.

Design of macromolecular prodrug of cisplatin using dextran with branched galactose units as targeting moieties to hepatoma cells

We previously reported that a macromolecular prodrug synthesized by immobilizing cisplatin (CDDP) to dextran (Dex) through six-membered chelate-type coordination bond (DCM-Dex/CDDP conjugate) showed a significantly longer half-life in bloodstream and excellent in vivo tumor growth inhibitory effect against mice bearing Colon 26 cancer cells. In this report, to provide DCM-Dex/CDDP conjugate having targetability to hepatoma cells, we designed a new macromolecular prodrug of CDDP using dextran having branched galactose units (Gal4As, four branched galactose residues), DCM-Dex/Gal4A/CDDP conjugate. Galactose was employed as a homing device, because it is well-known that galactose receptors (asialoglycoprotein receptors) were exposed on the surface of liver parenchymal cells. The antennary (branched) structure of Gal4A was designed based on the fact that a saccharide cluster having a branched structure shows highly effective binding with the saccharide receptors, that is a "cluster effect". The apparent affinity constant per galactose residue against RCA120 lectin for dextran carrying Gal4As was higher than that for dextran carrying monomeric galactose residues. Moreover, the DCM-Dex/Gal4A/CDDP conjugate showed cell-specific cytotoxic activity against HepG2 human hepatoma cells in vitro. The cytotoxic activity of the conjugate was inhibited by the addition of galactose and strongly inhibited by the addition of Gal4A. The results suggest that the DCM-Dex/Gal4A/CDDP conjugate having branched galactose units has a higher affinity to hepatoma cells.

Enlarged focal nodular hyperplasia of the liver under the influence of oral contraceptives

Two cases of focal nodular hyperplasia of the liver in mature women treated with the oral contraceptive are described. Radiological investigations in one case revealed the typical findings of focal nodular hyperplasia with computed tomography and magnetic resonance imaging demonstrating central scar structures while spoke-wheel appearance was evident on arteriography, in the other case however findings were atypical. Routine investigations including liver function tests and alpha-fetoprotein levels were normal while hepatitis B surface antigen and hepatitis C virus antibody were negative. The lesions of these two cases enlarged significantly during the follow-up and they were therefore surgically resected. Pathological features of both resected specimens, such as hepatocellular hyperplasia, bile duct proliferation and vascular abnormalities, were compatible with focal nodular hyperplasia. It has been suggested that tumor growth may be augmented by sex hormone stimulation and therefore estrogen and progesterone receptor expressions in the resected tumors were determined by immunocytochemistry. Interestingly, stainings for both receptors were negative. In case 2, the tumor was enlarging although oral contraceptive use had been discontinued for the past 7 years. These results suggest that there is no direct relationship of focal nodular hyperplasia with oral contraceptives. The role of sex hormones in focal nodular hyperplasia of the liver merits further study.

Diffuse intrasinusoidal liver metastasis of small cell lung cancer causing fulminant hepatic failure: CT findings-a case report

A 65-year-old man with small cell lung cancer treated with two courses of chemotherapy manifested appetite loss and abdominal distention 10 days before admission. Helical CT scanning of the abdomen and pelvis disclosed marked hepatomegaly without any visible nodular lesion in the hepatic parenchyma. He died of severe liver dysfunction with multiorgan failure on the 20th hospital day. Autopsy revealed diffuse invasion of tumor cells into the sinusoid throughout the liver.

Tumor suppressor p53 is required to modulate BRCA1 expression

Individuals carrying mutations in BRCA1 or p53 genes are predisposed to a variety of cancers, and both tumor suppressor genes have been implicated in DNA damage response pathways. We have analyzed a possible functional link between p53 and BRCA1 genes. Here we show that BRCA1 expression levels are down-regulated in response to p53 induction in cells that undergo either growth arrest, senescence, or apoptosis. Physiological stimuli, such as exposure to DNA-damaging agents, also result in negative regulation of BRCA1 levels in a p53-dependent manner prior to causing cell cycle arrest. Nuclear run-on experiments and luciferase reporter assays demonstrate that the changes in BRCA1 expression are mainly due to transcriptional repression induced by p53. In conclusion, the data show that BRCA1 expression levels are controlled by the presence and activity of wild-type p53 and suggest the existence of an intracellular p53/BRCA1 pathway in the response of cells to stress conditions.

Sustained activation of Ras/Raf/mitogen-activated protein kinase cascade by the tumor suppressor p53

The p53 tumor suppressor gene can inhibit proliferation transiently, induce permanent cell-cycle arrest/senescence, or cause apoptosis depending on the cellular context. The mitogen-activated protein kinase (MAPK) cascade is known to play a crucial role in cell proliferation and differentiation. Moreover, the duration and intensity of MAPK activation can profoundly influence the biological response observed. We demonstrated that a sustained activation of MAPK cascade could be induced by wild-type p53 expression but not by p21(Waf1/Cip1). Furthermore, exposure of normal cells to DNA-damaging agents induced MAPK activation in a p53-dependent manner. Tumor-derived p53 mutants defective in DNA binding failed to activate MAPK, implying that p53 transcriptional activity is essential for this function. Finally, activation of MAPK by p53 was inhibited by expression of dominant-negative Ras (N17Ras) and Raf1 mutants, indicating that MAPK activation by p53 is mediated at a level upstream of Ras. All of these findings establish a biochemical link between p53 signaling and the Ras/Raf/MAPK cascade.

The kinase-deficient Src acts as a suppressor of the Abl kinase for Cbl phosphorylation

The kinase activity of Abl is known to be regulated by a putative trans-acting inhibitor molecule interacting with the Src homology (SH) 3 domain of Abl. Here we report that the kinase-deficient Src (SrcKD) directly inhibits the tyrosine phosphorylation of Cbl and other cellular proteins by Abl. We found that both the SH2 and SH3 domains of SrcKD are necessary for the suppressor activity toward the Abl kinase phosphorylating Cbl. To suppress the Cbl phosphorylation by Abl, the interaction between the SH3 domain of SrcKD and Cbl is required. This interaction between SrcKD and Cbl is regulated by a closed structure of Cbl. The binding of Abl to the extreme carboxyl-terminal region of Cbl unmasks the binding site of SrcKD to Cbl. This results in a ternary complex that inhibits the Abl-mediated phosphorylation of Cbl by steric hindrance. These results illustrate a mechanism by which the enzymatically inactive Src can exert a biological function in vivo.

Collaboration of signal transducer and activator of transcription 1 (STAT1) and BRCA1 in differential regulation of IFN-gamma target genes

Most of the activities of IFN-gamma are the result of STAT1-mediated transcriptional responses. In this study, we show that the BRCA1 tumor suppressor acts in concert with STAT1 to differentially activate transcription of a subset of IFN-gamma target genes and mediates growth inhibition by this cytokine. After IFN-gamma treatment, induction of the cyclin-dependent kinase inhibitor, p21WAF1, was synergistically activated by BRCA1, whereas the IRF-1 gene was unaffected. Importantly, the differential induction of p21WAF1 was impaired in breast cancer cells homozygous for the mutant BRCA1 5382C allele. Biochemical analysis illustrated that the mechanism of this transcriptional synergy involves interaction between BRCA1 aa 502-802 and the C-terminal transcriptional activation domain of STAT1 including Ser-727 whose phosphorylation is crucial for transcriptional activation. Significantly, STAT1 proteins mutated at Ser-727 bind poorly to BRCA1, reinforcing the importance of Ser-727 in the recruitment of transcriptional coactivators by STAT proteins. These findings reveal a novel mechanism for BRCA1 function in the IFN-gamma-dependent tumor surveillance system.

[Electrophysiological evaluation of the protective effect of dimethylthiourea against retinal photic injury]

PURPOSE

The Protective effect of dimethylthiourea (DMTU) against photic injury of the retina was evaluated by electroretinogram (ERG).

METHODS

In the DMTU-treated group, 250, 500, or 750 mg/kg DMTU was administered intraperitoneally to albino rabbits at 24 hours and immediately before starting light exposure to the eye. In the control group, physiological saline was injected intraperitoneally instead of DMTU. Preservation rates of ERG a-, b- and c-wave amplitudes were defined as the percentages of the post-photic injury values to the pre-photic injury ones, and were compared between the control and the DMTU-treated groups.

RESULTS

In 750 mg/kg DMTU-treated group, the preservation rate of the a-wave was significantly higher than that in the control group 24 hours after the photic injury. While the preservation rate of the c-wave was remarkably low in the control group 24 hours after the photic injury, it was significantly higher in the 500 and 750 mg/kg DMTU-treated groups. Furthermore, better preservation rates of the c-wave were noted with higher doses of DMTU.

CONCLUSION

These results suggest that DMTU protects against photic injury of the retinal pigment epithelium and photoreceptors.

An ileostomy at the aganglionic ileum for total colon aganglionosis

For the initial management of total colon aganglionosis (TCA), an ileostomy is usually created at the distal end of the ganglionic bowel, which is associated with profuse diarrhea resulting in a water and electrolyte imbalance as well as malnutrition during the ileostomy period. An ileostomy at the aganglionic ileum several centimeters toward the anal side of the transition for TCA is thus expected to cause bowel retention without any bowel obstruction and to facilitate water reabsorption in the small bowel. We performed this procedure in 2 babies with TCA. The length of the aganglionic ileum was 50 cm and 10 cm, respectively. The ileostomies were made 5 cm distal to the transition at 1 month and 1 day after birth, respectively. Oral feedings were well tolerated, resulting in adequate weight gain and the stools were semisolid during the ileostomy periods. Definitive operations using the Duhamel procedure with a right colon patch graft without the creation of a new ileostomy were successfully performed at 7 and 3 months of age, respectively. The postoperative courses were satisfactory. An ileostomy at the aganglionic ileum appears to be the method of choice as initial management for patients with TCA.

A case of biliary atresia with cystic dilatation of the extrahepatic bile duct and polysplenia syndrome

A 79-day-old girl presented with jaundice and acholia. Laboratory findings disclosed elevated levels of bilirubin, transaminases, and gamma-glutamyl transferase. A chest X-ray film showed dextrocardia. A computed tomographic scan revealed a cystic mass at the porta hepatis, multiple spleens in the right side of the abdomen, and absence of the inferior vena cava. Under the diagnosis of biliary atresia (BA) (I-cyst) associated with polysplenia syndrome, a hepatic portojejunostomy was performed at 80 days of age. The postoperative course was uneventful, and the jaundice cleared. Although the occurrence of associated anomalies in BA is rare, polysplenia is most commonly seen, and its incidence is reported to be 2% to 10%. Patients with BA and polysplenia usually have a poor prognosis, however, this patient may have a good prognosis due to uneventful recovery from the jaundice.

Antitumor activity of dextran derivatives immobilizing platinum complex (II)

The in vivo antitumor activity and toxicity of a newly synthesized polymeric prodrug of cisplatin was investigated and also compared with plain cisplatin. The prodrug included a dicarboxymethyl-dextran conjugate of cisplatin (DCM-Dex/CDDP). DCM-Dex/CDDP was i.v. injected in mice bearing s.c. Colon 26 mouse colon cancer cells. The tissue distribution of platinum was thereafter determined by flameless atomic absorption spectrophotometry. The platinic concentration of the organs showed a high rate of retention at 24 h after injection in the DCM-Dex/CDDP-treated mice. No biochemical or hematologically adverse effects were observed. In addition, DCM-Dex/CDDP showed a significantly higher antitumor activity than cisplatin alone. These results indicate that DCM-Dex/CDDP may therefore be a potentially effective cancer chemotherapy.