[Measurements of cerebral blood flow by the noninvasive microsphere method with 123I-IMP and fan beam collimator: comparison with the continuous arterial blood sampling method]

PURPOSE AND METHODS

The noninvasive microsphere (NIMS) method quantifies cerebral blood flow with N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) without blood sampling of a patient, but when a fan beam collimator is used for collecting raw data in single photon emission computed tomography (SPECT), the procedure is complicated because we have to change the collimator. In phantom and clinical studies we investigated the validity of using a fan beam collimator in collecting planar and SPECT raw data.

RESULTS

The phantom study suggested that using a fan beam collimator for planar imaging was feasible because of the image magnification rate and the count rate. Mean cerebral blood flow (mCBF) values obtained by the NIMS method with the fan beam collimator were compared with mCBF simultaneously estimated from the conventional continuous arterial blood sampling (microsphere: MS) method in twenty patients with ischemic cerebral vascular diseases. There was good correlation (y = 1.033x + 8.004, r2 = 0.729, p < 0.01) in mCBF between the fan beam NIMS method and the MS method.

CONCLUSION

In conclusion, this method for the measurement of CBF was acceptable for routine clinical studies.

Free vascularized nail graft under digital block

Vascularized toenail grafts with long vascular pedicles have usually been transferred under general anesthesia. In this paper, a minimally invasive vascularized nail graft with a short pedicle and small cutaneous flap, which was successfully transferred under digital block of the finger and toe, is described.

Modification of photosystem I reaction center by the extraction and exchange of chlorophylls and quinones

The photosystem (PS) I photosynthetic reaction center was modified thorough the selective extraction and exchange of chlorophylls and quinones. Extraction of lyophilized photosystem I complex with diethyl ether depleted more than 90% chlorophyll (Chl) molecules bound to the complex, preserving the photochemical electron transfer activity from the primary electron donor P700 to the acceptor chlorophyll A(0). The treatment extracted all the carotenoids and the secondary acceptor phylloquinone (A(1)), and produced a PS I reaction center that contains nine molecules of Chls including P700 and A(0), and three Fe-S clusters (F(X), F(A) and F(B)). The ether-extracted PS I complex showed fast electron transfer from P700 to A(0) as it is, and to FeS clusters if phylloquinone or an appropriate artificial quinone was reconstituted as A(1). The ether-extracted PS I enabled accurate detection of the primary photoreactions with little disturbance from the absorbance changes of the bulk pigments. The quinone reconstitution created the new reactions between the artificial cofactors and the intrinsic components with altered energy gaps. We review the studies done in the ether-extracted PS I complex including chlorophyll forms of the core moiety of PS I, fluorescence of P700, reaction rate between A(0) and reconstituted A(1), and the fast electron transfer from P700 to A(0). Natural exchange of chlorophyll a to 710-740 nm absorbing chlorophyll d in PS I of the newly found cyanobacteria-like organism Acaryochloris marina was also reviewed. Based on the results of exchange studies in different systems, designs of photosynthetic reaction centers are discussed.

Cerebral metabolism and regional cerebral blood flow during moderate systemic cooling in newborn piglets

BACKGROUND

Clinical trials of hypothermic therapy in asphyxiated infants have started recently. However, clinical studies have been delayed by the difficulty in selecting infants with a bad neurological prognosis and by the concern regarding adverse effects of hypothermia. The purpose of this study is to examine the effects of systemic cooling on cerebral metabolism (CMR) and the regional cerebral blood flow (rCBF) in newborn piglets.

METHODS

The rCBF in the seven parts of the brain were measured with colored microspheres. The blood samples for the measurement of cerebral oxygen consumption (CMRO2) and cerebral glucose consumption (CMRglc) was collected from the umbilical artery and the superior sagittal sinus.

RESULTS

Reductions of cerebral cortex temperature to 32 degrees C decreased blood flow in all brain regions. In particular, blood flow in the brainstem decreased more significantly than in any other region. The total cerebral blood flow (CBF), CMRO2 and CMRglc, respectively, decreased to 32.3+/-3.9 mL/100 g per min, 2.8+/-1.0 mLO2/100 g per min and 22+/-12 mmol/100 g per min at 32 degrees C (41, 53 and 46% of the initial value). The CBF decreased in parallel with CMRO2 and CMRglc down to 35 degrees C, but CBF decreased to a greater extent than CMRO2 and CMRglc at below 35 degrees C.

CONCLUSIONS

The indication of hypothermic therapy and the degree of cooling have to be performed very carefully. Systemic cooling is especially dangerous for the total asphyxiated infants who might have damage to the brainstem because the blood flow in the brainstem has significantly decreased during hypothermia.

Enantioselective binding of disopyramide to alpha1-acid glycoprotein and its variants

OBJECTIVE

alpha1-acid glycoprotein (AAG) has three main genetic variants, F1, S, and A variants. There are few reports on the correlation between AAG variants and binding activity of drug enantiomers. We studied the differences between the binding characteristics of enantiomers of disopyramide (DP), which is a basic drug. The aim of this study was to elucidate the cause of the differences between the binding characteristics of DP enantiomers.

METHODS

The variants in human AAG were separated by hydroxyapatite chromatography. Binding of DP enantiomers to AAG variants was studied by the ultrafiltration method. The characteristics of the binding of DP enantiomers to total variants and each variant were examined by Scatchard analysis within a range of concentrations from 0.5 to 50.0 microg/ml.

RESULTS

The binding capacity of S-DP was significantly higher than that of R-DP in variant 3, although the binding capacities of DP enantiomers were almost the same in variant 2. On the other hand, the binding capacities for both S-DP and R-DP in variant 3 were significantly higher than those in variant 2. Furthermore, there was an almost 2.4-fold difference in the dissociation constant (Kd) between S-DP and R-DP in variant 3, although no significant difference was observed in the number of binding sites (N). In variant 2 no significant differences between DP enantiomers were observed in either the dissociation constant or number of binding sites per molecule of AAG. On the other hand, significant differences between variants 2 and 3 in the dissociation constant for both S-DP and R-DP were observed. The differences in dissociation constant between variants 2 and 3 were 4.0-fold in S-DP and 1.7-fold in R-DP.

CONCLUSION

The difference between the binding capacities of S-DP and R-DP is due to differences in the association of DP to variants 3-6, and the role of the variants 1 and 2 in the binding of drugs to AAG is minor.

Catalytic control of redox reactivities of coenzyme analogs by metal ions

Redox coenzymes and analogs have their own redox reactivities for both thermal and photochemical redox reactions. The redox activities of coenzymes can be tuned by using metal ions that can bind the redox coenzymes and analogs. Quantitative measure to determine the Lewis acidity of a variety of metal ions is given in relation to the catalytic reactivities. The mechanistic viability of metal ion catalysis in redox reactions of coenzyme analogs is described by showing a number of examples of both thermal and photochemical reactions that are made possible to proceed by controlling the redox reactivities of coenzymes with metal ions.

Tissue-specific autoregulation of the stat3 gene and its role in interleukin-6-induced survival signals in T cells

Signal transducer and activator of transcription 3 (STAT3) mediates signals of various growth factors and cytokines, including interleukin-6 (IL-6). In certain IL-6-responsive cell lines, the stat3 gene is autoregulated by STAT3 through a composite IL-6 response element in its promoter that contains a STAT3-binding element (SBE) and a cyclic AMP-responsive element. To reveal the nature and roles of the stat3 autoregulation in vivo, we generated mice that harbor a mutation in the SBE (stat3(mSBE)). The intact SBE was crucial for IL-6-induced stat3 gene activation in the spleen, especially in the red pulp region, the kidney, and both mature and immature T lymphocytes. The SBE was not required, however, for IL-6-induced stat3 gene activation in hepatocytes. T lymphocytes from the stat3(mSBE/mSBE) mice were more susceptible to apoptosis despite the presence of IL-6 than those from wild-type mice. Consistent with this, IL-6-dependent activation of the Pim-1 and junB genes, direct target genes for STAT3, was attenuated in T lymphocytes of the stat3(mSBE/mSBE) mice. Thus, the tissue-specific autoregulation of the stat3 gene operates in vivo and plays a role in IL-6-induced antiapoptotic signaling in T cells.

Novel murine autoimmune-mediated liver disease model induced by graft-versus-host reaction and concanavalin A

BACKGROUND AND AIMS

We have previously reported that cluster of differentiation (CD)4+ T cells induced autoimmune liver diseases in mice with graft-versus-host reaction (GVHR) because of major histocompatibility complex (MHC) class II disparity. To analyze the progression of the autoimmune-related mechanism in the liver, concanavalin A (Con A) was injected in mice undergoing GVHR. The aim of this study is to clarify whether Con A deteriorates murine hepatic lesions induced by GVHR, and to elucidate the participation of the cytokines of liver-infiltrating CD4+ T cells.

METHODS

Mice (F1; B6.C-H-2(bm12) x B6) were intravenously injected with B6 T spleen cells. Concanavalin A (15 mg/kg) was administrated 5 days after cell transfer. We examined serum transaminase, antimitochondrial antibodies (AMA), antinuclear antibodies (ANA) and histological changes. Liver-infiltrating CD4+ T cells were sorted and their cytokine mRNA expression was examined by the use of reverse transcription-polymerase chain reaction (RT-PCR).

RESULTS

Graft-versus-host reaction + Con A mice revealed an elevated serum transaminase, elevated AMA and ANA titers, increased periportal cellular infiltration, piecemeal necrosis and bridging necrosis in the liver. In this group, interferon (IFN)-gamma mRNA expression was more elevated than it was in the GVHR mice. However, there was no difference in the expression of interleukin (IL)-10 mRNA between the two groups.

CONCLUSION

The results suggest that Con A deteriorates the GVHR-induced hepatic lesions, and IFN-gamma and IL-10 of CD4+ T cells might be implicated in the progression of autoimmune-related hepatic lesions. This model might offer an aspect for the investigation of progressive mechanisms in T-cell- mediated hepatobiliary injury.

Oxidative modification of tryptophan 43 in the heme vicinity of the F43W/H64L myoglobin mutant

The F43W/H64L myoglobin mutant was previously constructed to investigate the effects of electron-rich tryptophan residue in the heme vicinity on the catalysis, where we found that Trp-43 in the mutant was oxidatively modified in the reaction with m-chloroperbenzoic acid (mCPBA). To identify the exact structure of the modified tryptophan in this study, the mCPBA-treated F43W/H64L mutant has been digested stepwise with Lys-C achromobacter and trypsin to isolate two oxidation products by preparative fast protein liquid chromatography. The close examinations of the (1)H NMR spectra of peptide fragments reveal that two forms of the modified tryptophan must have 2,6-disubstituted indole substructures. The (13)C NMR analysis suggests that one of the modified tryptophan bears a unique hydroxyl group in stead of the NH(2) group at the amino-terminal. The results together with mass spectrometry (MS)/MS analysis (30 Da increase in mass of Trp-43) indicate that oxidation products of Trp-43 are 2,6-dihydro-2,6-dioxoindole and 2,6-dihydro-2-imino-6-oxoindole derivatives. Our finding is the first example of the oxidation of aromatic carbons by the myoglobin mutant system.

Identification of splicing variants of Frabin with partly different functions and tissue distribution

Frabin is a GDP/GTP exchange protein for Cdc42 small G protein with actin filament-binding activity. Frabin consists of the actin filament-binding domain, the Dbl homology domain, the first pleckstrin homology domain, the FYVE-finger domain, and the second pleckstrin homology domain in this order from the N-terminus. Frabin forms filopodia through direct activation of Cdc42 and lamellipodia through indirect activation of Rac small G protein. We isolated here two smaller splicing variants of frabin and named the original one, middle-size one, and smallest one frabin-alpha, -beta, and -gamma, respectively. Frabin-beta lacked the second pleckstrin homology domain and frabin-gamma lacked the FYVE-finger domain and the second pleckstrin homology domain. These three variants were expressed in all of the tissues examined but their expression levels are different depending on tissues. In L fibroblasts, all the three variants formed filopodia. As to lamellipodia, frabin-alpha formed them; frabin-beta formed them to a small extent; and frabin-gamma did not. In MDCK epithelial cells, frabin-alpha formed microspikes but frabin-beta or -gamma did not.

Involvement of heat shock proteins in the healing of acetic acid-induced gastric ulcers in rats

The present study examined the expression of 73-kDa of heat shock cognate protein (HSC70), 72-kDa of heat shock protein (HSP70) and 47-kDa of HSP (HSP47) observed in the ulcer healing process in rats. Gastric ulcers were induced by a luminal application of acetic acid in male Donryu rats. During the ulcer healing process, the expression of HSPs in the ulcerated tissue was determined. A high level of HSC70 expression was observed both in the normal mucosa and ulcerated tissue, but the level did not change upon ulceration and ulcer healing. While HSP70 and HSP47 were markedly expressed in the ulcer base during ulceration, and decreased with ulcer healing. HSP70 expression in the ulcer margin was gradually increased with ulcer healing. Omeprazole accelerated the healing of gastric ulcers with strong inhibition of gastric acid secretion, while indomethactin delayed in ulcer healing despite slight inhibition of gastric acid secretion. Omperazole enhanced the expression of HSP70 both in the ulcer margin and base, but it reduced HSP47 expression in the ulcer base Indomethacin markedly enhanced HSP47 expression only in the ulcer base. In conclusion, the expression of HSP70 and HSP47 is changed during ulcer healing. Furthermore, it was suggested that the enhanced expression of HSP70 is involved in acceleration of ulcer healing, but overexpression of HSP47 is involved in delayed ulcer healing.

Transient spontaneous regression of aggressive non-Hodgkin's lymphoma confined to the adrenal glands

A 72-year-old-man with night sweats and a low-grade fever was found to have bilateral adrenal enlargement associated with incipient adrenal insufficiency. Without any intervention, these adrenal lesions regressed spontaneously, accompanied by disappearance of clinical symptoms. Seven months later, however, the lesions became enlarged and exceeded their initial size while remaining confined to the adrenals, associated with reappearance of nights sweats and overt adrenal insufficiency. Upon unilateral laparoscopic adrenalectomy, the lesion proved histopathologically to be diffuse large B cell non-Hodgkin's lymphoma (NHL). After contralateral laparoscopic adrenalectomy and adjuvant chemotherapy, the patient remains alive with no recurrence at 26 months. Treatment with bilateral adrenalectomy and chemotherapy is effective for aggressive NHL confined to bilateral adrenal glands. A transient clinical improvement without treatment was considered to be due to a spontaneous regression of NHL, although we could not confirm the histological results before the regression. Such tumor behavior showing spontaneous regression in spite of aggressive histology may also be related to the favorable outcome, even though regression was transient.

Changes of activity inducing chromosomal aberrations and transformations of chlorinated humic acid

The change of the toxicity of chlorinated water after chlorine injection was examined. For the measurement of toxicity, chromosomal aberration test and transforming test were carried out as indexes to initiating activity and to promoting activity in the carcinogenesis process, respectively. Activity inducing chromosomal aberrations of chlorinated humic acid gradually decreased with time after chlorination. In contrast, activity inducing transformations measured by the two-stage assay gradually increased. Thus, the toxicity that decreases or increases is present in chlorinated water. Furthermore, activity inducing transformations measured by the non-two-stage assay gradually decreased. This direction of change was reverse to that of activity inducing transformations by the two-stage assay and consistent with that of activity inducing chromosomal aberrations. It is speculated that the main reason of decreasing activity inducing transformations by the non-two-stage assay is because initiating activity detected as activity inducing chromosomal aberrations in chlorinated water decreases drastically. Directions of changes of total organic halogen and carbonyl group were qualitatively consistent with that of activity inducing chromosomal aberrations. Directions of changes of chloroform and dichloroacetic acid were qualitatively consistent with that of activity inducing transformations by the two-stage assay. Findings of this study suggest that further research is necessary to compare carcinogenicity of tap water near water purification plant and distant tap water.

Self-organization mechanism in a bone-like hydroxyapatite/collagen nanocomposite synthesized in vitro and its biological reaction in vivo

When bone is lost due to injury and/or illness, the defects are generally filled with natural bone because artificial bone materials have problems of bioaffinity. However, natural bone also has supply and infection problems. If an artificial material has the same biological properties as bone, it can replace natural bone for grafting. We synthesized a hydroxyapaite (HAp) and collagen (Col) composite by a simultaneous titration coprecipitation method using Ca(OH)2, H3PO4 and porcine atelocollagen as starting materials. The composite obtained showed a self-organized nanostructure similar to bone assembled by the chemical interaction between HAp and Col. The consolidated composite by a cold isostatic pressure of 200 MPa indicated a quarter of the mechanical strength of bone. It also indicated the same biological properties as grafted bone: The material was resorbed by phagocytosis of osteoclast-like cells and conducted osteoblasts to form new bone in the surrounding area. This HAp/Col composite having similar nanostructure and composition can replace autologous bone grafts.

Time of closure of ductus venosus in term and preterm neonates

AIM

To investigate the relation between gestational age, birth weight, and antenatal corticosteroid administration and the time of ductus venosus closure.

METHODS

Ninety eight neonates of 30-41 weeks gestational age were studied by daily ultrasonography until ductus venosus closure.

RESULTS

In neonates of 30-33 weeks gestational age, the ductus venosus closed at 6.0 (2.4)days (mean (SD)); in those of 34-36 weeks gestational age, it closed at 6.1 (2.8) days; and in those of 37-41 weeks gestational age, it closed at 4.2 (2.1) days. The effect of antenatal administration of corticosteroids on the time of closure was also investigated in neonates of 30-34 weeks gestational age. Closure occurred by 5.5 (2.4) days in the group given corticosteroids compared with 7.5 (2.1) days in the remainder.

CONCLUSIONS

The ductus venosus closed sooner after birth in neonates of greater gestational age or higher birth weight. Antenatal corticosteroid administration had a significant effect in promoting closure.

Application of resampling techniques to the statistical analysis of the Brier score

We investigated the application of resampling techniques to the statistical analysis of the Brier score (B), and extended them to the statistical comparison of two Bs derived from the same set of patients. The resampling techniques are helpful in the statistical analysis of B, and there are almost no differences between the jackknife method and the bootstrap method in this analysis. Thus, we believe that B should be used more often as an index to evaluate probabilistic judgments in the case in which the data sets for the assessment are "degenerate" as the "receiver operating characteristic data sets."

Automated detection of pulmonary nodules in helical CT images based on an improved template-matching technique

The purpose of this study is to develop a technique for computer-aided diagnosis (CAD) systems to detect lung nodules in helical X-ray pulmonary computed tomography CT) images. We propose a novel template-matching technique based on a genetic algorithm (GA) template matching (GATM) for detecting nodules existing within the lung area; the GA was used to determine the target position in the observed image efficiently and to select an adequate template image from several reference patterns for quick template matching. In addition, a conventional template matching was employed to detect nodules existing on the lung wall area, lung wall template matching (LWTM), where semicircular models were used as reference patterns; the semicircular models were rotated according to the angle of the target point on the contour of the lung wall. After initial detecting candidates using the two template-matching methods, we extracted a total of 13 feature values and used them to eliminate false-positive findings. Twenty clinical cases involving a total of 557 sectional images were used in this study. 71 nodules out of 98 were correctly detected by our scheme (i.e., a detection rate of about 72%), with the number of false positives at approximately 1.1/sectional image. Our present results show that our scheme can be regarded as a technique for CAD systems to detect nodules in helical CT pulmonary images.

Enhancement of bone ingrowth in a titanium fiber mesh implant by rhBMP-2 and hyaluronic acid

The present study was designed to evaluate the efficacy of high molecular weight hyaluronic acid (HA) used as a carrier of recombinant human bone morphogenetic protein-2 (rhBMP-2) adsorbed to a titanium fiber mesh implant (TFMI) in vivo. The quantity of HA in the TFMI rapidly decreased during the initial 3-day period after implantation. BMP particles were trapped by the meshwork of HA as observed by scanning electron microscopy (SEM). TFMIs containing LF-6, HA, rhBMP-2, or HA combined with rhBMP-2 were implanted on the cranium of rats. Analysis of digitized SEM images of samples obtained six weeks post-implantation was performed to determine the area occupied by new bone. The area fraction of Ca relative to that of the pores of TFMI in the HA group was larger than that in the Ti group (p<0.05). The area fraction of Ca in both the BMP and HA+BMP groups was larger than that in both the Ti and HA groups (p<0.01), and that in the HA+BMP group was larger than that in the BMP group (p<0.05). It is suggested that HA is not only an effective carrier of BMP, but also it may have a positive effect on the generation of new bone in the TFMI.

The genetic factor in acute myocardial infarction with hypertension

This study assessed the contribution of polymorphisms of angiotensin II (AngII) receptors and bradykinin B2 (BK-B2) receptor to hypertension and acute myocardial infarction (AMI) in a Japanese population: 150 subjects with essential hypertension, 150 subjects with AMI with/without hypertension, and 150 healthy, age- and sex-matched controls. Polymorphisms of the AngII type 1 receptor (1166 A/C) and type 2 receptor (3123 C/A), and the BK-B2 receptor (-58T/C, exon 1) were analyzed and significant differences of genotypes and allelic frequencies in the AngII type 2 receptor C/A and BK-B2 receptor -58T/C were found between the essential hypertension and control subjects. Further, a significantly higher incidence of the C allele of the BK-B2 receptor was seen in AMI subjects with hypertension compared with those without hypertension. Genetic variations in the AngII and BK-B2 receptors could prove to be significant pathophysiological mechanisms affecting essential hypertension and AMI, and genetic differences appear to be a new risk factor for these conditions.

CT and MR imaging of pancreatic cancer

Recent improvements in imaging techniques have made it possible to improve the diagnostic accuracy for detection, staging, and indicating surgical resectability of pancreatic cancer. The latest advance in the computed tomography technique, is the introduction of subsecond multislice helical scanning that improves z-axis resolution in the reformatted images and three-dimensional rendering with a large volume data. Magnetic resonance imaging provides versatile information including magnetic resonance cholangiopancreatography that allows noninvasive delineation of the pancreatic and biliary duct systems. The presence of pancreatic cancer may best be evaluated by dynamic computed tomography or dynamic magnetic resonance imaging with administration of intravenous contrast material. Both computed tomography and magnetic resonance imaging are valuable for the preoperative assessment of local invasion and vascular involvement. Multislice helical computed tomography is currently considered as the best single modality for the diagnosis of pancreatic cancer as it provides excellent image quality. When advanced magnetic resonance imaging equipment is used as a primary modality, in the future, it may have a possibility to replace other imaging modalities.

Relationships between serum (ZZ)-bilirubin, its subfractions and biliverdin concentrations in infants at 1-month check-ups

In 150 infants, including those with breast milk jaundice, who were brought to our hospital for their 1-month check-ups, the serum concentrations of (ZZ)-bilirubin, its subfractions and biliverdin were measured by high-performance liquid chromatography and the relationships among them investigated. (ZZ)-Bilirubin was found to have the highest serum concentration, followed by (ZE)-bilirubin, accounting for 14.0 (geometric mean) % of (ZZ)-bilirubin. Biliverdin had a serum concentration of 0.95% of (ZZ)-bilirubin. There was only a small amount of total (di- and mono-) glucuronosyl bilirubin, 0.42% of (ZZ)-bilirubin. (ZE)-Bilirubin, (EZ)-bilirubin, (EZ)-cyclobilirubin. biliverdin, diglucuronosyl bilirubin and monoglucuronosyl bilirubin (C-8 and C-12) showed positive logarithmic correlations with (ZZ)-bilirubin (R2=0.16 or above, P<0.05). (ZE)-Bilirubin showed a significant positive logarithmic correlation with (ZZ)-bilirubin (R2=0.863, P<0.0001). Furthermore, (EZ)-cyclobilirubin, the most important photoisomer in phototherapy for neonatal hyperbilirubinaemia, was detected in very small amounts in approximately half of the neonates (84 of 150) when they were in conditions of only weak ambient light. The relationship between total glucuronosyl bilirubin and (ZZ)-bilirubin concentrations fitted a model of saturation kinetics of bilirubin UDP-glucuronosyltransferase.

A 10-year-old boy with Marfan syndrome exhibiting cerebrovascular abnormalities

A young male with Marfan syndrome, diagnosed at the age of 10 years, presented with conspicuous elongation and tortuosity of the internal carotid, middle cerebral, vertebral and basilar arteries on cranial magnetic resonance and computed tomography angiography. There is a little mention of cerebral blood vessel examinations in the guidelines of the American Academy of Pediatrics for Marfan syndrome. Guidelines may be provided for the evaluation of cerebrovascular system for the patients with Marfan syndrome who have family history of Marfan syndrome as well as a family history of death from subarachnoid hemorrhage.

Internal transport barrier triggered by neoclassical transport in W7-AS

The three-dimensional magnetic configuration of a stellarator offers two specific mechanisms for a transition to improved particle and energy confinement. One route goes through the so-called electron-root confinement regime, which leads to a reduction of neoclassical transport via strong radial electric fields. In this Letter evidence for a second route is presented. It opens due to the layer of a strongly varying radial electric field which is present in the transitional region from neoclassical electron to ion-root confinement. This type of improvement acts on turbulent transport.

Characterization of imidazolate-bridged dinuclear and mononuclear hydroperoxo complexes

Dinucleating ligands having two metal-binding sites bridged by an imidazolate moiety, Hbdpi, HMe(2)bdpi, and HMe(4)bdpi (Hbdpi = 4,5-bis(di(2-pyridylmethyl)aminomethyl)imidazole, HMe(2)bdpi = 4,5-bis((6-methyl-2-pyridylmethyl)(2-pyridylmethyl)aminomethyl)imidazole, HMe(4)bdpi = 4,5-bis(di(6-methyl-2-pyridylmethyl)aminomethyl)imidazole), have been designed and synthesized as model ligands for copper-zinc superoxide dismutase (Cu,Zn-SOD). The corresponding mononucleating ligands, MeIm(Py)(2), MeIm(Me)(1), and MeIm(Me)(2) (MeIm(Py)(2) = (1-methyl-4-imidazolylmethyl)bis(2-pyridylmethyl)amine, MeIm(Me)(1) = (1-methyl-4-imidazolylmethyl)(6-methyl-2-pyridylmethyl)(2-pyridylmethyl)amine, MeIm(Me)(2) = (1-methyl-4-imidazolyl-methyl)bis(6-methyl-2-pyridylmethyl)amine), have also been synthesized for comparison. The imidazolate-bridged Cu(II)-Cu(II) homodinuclear complexes represented as [Cu(2)(bdpi)(CH(3)CN)(2)](ClO(4))(3).CH(3)CN.3H(2)O (1), [Cu(2)(Me(2)bdpi)(CH(3)CN)(2)](ClO(4))(3) (2), [Cu(2)(Me(4)bdpi)(H(2)O)(2)](ClO(4))(3).4H(2)O (3), a Cu(II)-Zn(II) heterodinuclear complex of the type of [CuZn(bdpi)(CH(3)CN)(2)](ClO(4))(3).2CH(3)CN (4), Cu(II) mononuclear complexes of [Cu(MeIm(Py)(2))(CH(3)CN)](ClO(4))(2).CH(3)CN (5), [Cu(MeIm(Me)(1))(CH(3)CN)](ClO(4))(2)( )()(6), and [Cu(MeIm(Me)(2))(CH(3)CN)](ClO(4))(2)( )()(7) have been synthesized and the structures of complexes 5-7 determined by X-ray crystallography. The complexes 1-7 have a pentacoordinate structure at each metal ion with the imidazolate or 1-methylimidazole nitrogen, two pyridine nitrogens, the tertiary amine nitrogen, and a solvent (CH(3)CN or H(2)O) which can be readily replaced by a substrate. The reactions between complexes 1-7 and hydrogen peroxide (H(2)O(2)) in the presence of a base at -80 degrees C yield green solutions which exhibit intense bands at 360-380 nm, consistent with the generation of hydroperoxo Cu(II) species in all cases. The resonance Raman spectra of all hydroperoxo intermediates at -80 degrees C exhibit a strong resonance-enhanced Raman band at 834-851 cm(-1), which shifts to 788-803 cm(-1) (Deltanu = 46 cm(-1)) when (18)O-labeled H(2)O(2) was used, which are assigned to the O-O stretching frequency of a hydroperoxo ion. The resonance Raman spectra of hydroperoxo adducts of complexes 2 and 6 show two Raman bands at 848 (802) and 834 (788), 851 (805), and 835 (789) cm(-1) (in the case of H(2)(18)O(2), Deltanu = 46 cm(-1)), respectively. The ESR spectra of all hydroperoxo complexes are quite close to those of the parent Cu(II) complexes except 6. The spectrum of 6 exhibits a mixture signal of trigonal-bipyramid and square-pyramid which is consistent with the results of resonance Raman spectrum.

Cyclobilirubin formation by in vitro photoirradiation with neonatal phototherapy light

BACKGROUND

The main mechanism of phototherapy for neonatal hyperbilirubinemia is the production and excretion of (EZ)- and (EE)-cyclobilirubin (4E,15Z- and 4E,15E-cyclobilirubin). Thus, the clinical efficacy of the light source for phototherapy must be evaluated by cyclobilirubin formation from (ZZ)-bilirubin in in vitro photoirradiation.

METHODS

In the present study, we investigated the in vitro production pattern of bilirubin photoisomers by phototherapy light from the bilirubin-human serum albumin complex.

RESULTS

No clear difference was found in the curves relative to (ZZ)-bilirubin and its photoisomers under aerobic and anaerobic conditions. The ratio of (EZ)-cyclobilirubin to (ZZ)-bilirubin increased proportionately to the dose of irradiating light and no photoequilibrium state was observed analogous to that found in configurational photoisomerization. The concentration of (EZ)- and (EE)-cyclobilirubin increased proportionately with the grade of the percentage decrease in A(460 nm) from 0 to 23%. With a percentage decrease in A(460 nm) of 23% or more, the cyclobilirubin concentrations reached a steady state. The reason for this appears to be that the concentration of (ZZ)-bilirubin, a substrate for photoisomers, dropped below 1 mg/100 mL. Biliverdin was produced only in trace amounts. However, the absorption at 520--700 nm increased after a percentage decrease in A(460 nm) of more than 23%.

CONCLUSIONS

The results of the present study show that little bilirubin photooxidation occurred with in vitro aerobic photoirradiation. Before the concentration of cyclobilirubin reaches a steady state, it is theoretically valid to use the percentage decrease in A(460 nm) for the evaluation of the clinical efficacy of the light source.

Effects of Isopropyl Unoprostone on Melanogenesis in Mouse Epidermal Melanocytes

PURPOSE

To investigate the effects of isopropyl unoprostone (referred to as unoprostone) on melanin synthesis and the nature of melanin.

METHODS

M1 and M2, potential intraocular oxidized metabolites of unoprostone, were added to the culture medium in a cultured immortal line of mouse epidermal melanocytes, melan-a, once a day for 2 weeks at concentrations of 5 nM and 50 nM. Vehicle solution was utilized as a control. The amounts of pyrrole-2,3,5-tricarboxylic acid (PTCA), an oxidized product of eumelanin, and aminohydroxyphenylalanine (AHP), a hydrolyzed product of pheomelanin, were measured by high-performance liquid chromatography.

RESULTS

A 5-nM concentration of M2 significantly increased PTCA production (20.84 +/- 3.17 ng/10(6) cells mean +/- SD) compared with the control (14.58 +/- 4.62 ng/10(6) cells) (P =.04), although other concentrations did not affect the synthesis of PTCA or AHP. A 5-nM concentration of M2 significantly increased the PTCA/AHP (1.86 +/- 0.18) ratio compared with the control (1.37 +/- 0.41) (P =.04). A 50 nM concentration of M2 slightly increased the PTCA/AHP (1.74 +/- 0.58) ratio, but M1 did not affect this ratio.

CONCLUSIONS

These results indicate that M2 affects not only melanogenesis but also the nature of melanin, which could result in unoprostone-generated iridial pigmentation.

Functional analysis of psbV and a novel c-type cytochrome gene psbV2 of the thermophilic cyanobacterium Thermosynechococcus elongatus strain BP-1

Cytochrome c-550 is an extrinsic protein associated with photosystem II (PSII) in cyanobacteria and lower eukaryotic algae and plays an important role in the water-splitting reaction. The gene (psbV) for cytochrome c-550 was cloned from the thermophilic cyanobacteria Thermosynechococcus (formerly Synechococcus) elongatus and T. (formerly Synechococcus) vulcanus. In both genomes, located downstream of psbV were a novel gene (designated psbV2) for a c-type cytochrome and petJ for cytochrome c-553. The deduced product of psbV2 showed composite similarities to psbV and petJ. Phenotype of psbV-disruptant in Thermosynechococcus was practically the same as that reported in Synechocystis sp. PCC 6803. Either psbV or psbV2 gene of T. elongatus was expressed in the psbV-disruptant of Synechocystis sp. PCC 6803, which resulted in recovery of the photoautotrophic growth. However, the enhanced requirement of Ca(2+) or Cl- ions in the psbV-disruptant of Synechocystis was suppressed by expression of psbV but not by expression of psbV2. Thus, it is concluded that psbV2 can partly replace the role of psbV in PSII. The close tandem arrangement of psbV/psbV2/petJ implies that psbV2 was created by gene duplication and intergenic recombination during evolution.

AT oligonucleotides inducing B lymphocyte activation exist in probiotic Lactobacillus gasseri

This study determined oligonucleotide sequences of mitogenic DNA derived from lactic acid bacteria (LAB). The chromosomal DNA, which was purified from 12 out of 16 strains of Lactobacillus acidophilus group LAB, induced proliferation of splenic lymphocytes. When DNA from L. gasseri JCM1131T was cloned and amplified using PCR, the mitogenic activities of B lymphocytes were significantly increased by 108 of 321 DNA clones. Ten high homologous nucleotide sequences were found as possible DNA sequences of mitogens, and were then chemically synthesized (sOL-LG1 to sOL-LG10). Two nucleotide sequences (sOL-LG7 and sOL-LG10) that consist of only A and T nucleotides (AT oligonucleotides) were characterized as B lymphocyte specific mitogens because they resulted in proliferation of B lymphocytes but not of T lymphocytes. sOL-LG7 preferentially bound to large B lymphocytes and enhanced the expression of the CD86 antigen more than the CD69 antigen on B lymphocytes. The findings show that mitogenic AT oligonucleotides are likely to restrict pre-activated subsets of B lymphocytes. This study demonstrated that novel AT oligonucleotides triggering B lymphocyte mitogenic responses exist in the nucleoids of L. gasseri and proposed that they have potential as applicants for the production of new functional foods, "Bio-Defense Foods".

Neuronal plasticity in hippocampal mossy fiber–CA3 synapses of mice lacking the inositol-1,4,5-trisphosphate type 1 receptor

In the present study, we used inositol-1,4,5-trisphosphate (IP3) type 1 receptor (IP3R1) knockout mice to examine the role of this receptor in the induction of LTP, LTD, and DP at mossy fiber-CA3 synapses. No difference in synaptically induced field-EPSPs was seen between the wild-type (IP3R1(+/+)) and IP3R1 knockout mice (IP3R1(-/-)), showing that basic synaptic transmission does not involve IP3R1 activation. Tetanus induced LTP in both wild-type and IP(3)R1(-/-) mice, but the magnitude of LTP was significantly greater in IP3R1(-/-) mice (149.8+/-3.5%, mean+/-S.E.M., n=15) than in wild-type mice (132.4+/-1.5%, n=17), suggesting that the IP3R1 has a suppressive effect on LTP induction. To determine whether this effect involved N-methyl-D-aspartate receptor (NMDAR)-dependent LTP, the effect of tetanus was tested in the present of the NMDAR antagonist, D,L-AP5 (50 microM); under these conditions, the LTP in both IP3R1(-/-) and IP3R1(+/+) mice was not significantly reduced. In addition, group I mGluR activation was shown to be necessary for LTP induction, as the LTP was almost blocked by the group I mGluR antagonist, RS-4CPG (500 microM) in both IP3R1(-/-) (117.6+/-1.7%, n=8) and IP3R1(+/+) (116.9+/-1.8%, n=5) mice. The IP3R1 also plays an essential role in LTD induction, as low-frequency stimulation (LFS) failed to induce LTD in the mutant mice (104.5+/-2.1%, n=10). DP was induced in both IP3R1(-/-) and wild-type mice.

CHOP, a basic leucine zipper transcriptional factor, contributes to the antiproliferative effect of IL-1 on A375 human melanoma cells through augmenting transcription of IL-6

Interleukin-1 (IL-1) inhibits the proliferation of A375 human melanoma cells. We have demonstrated previously that p38 mitrogen-activated protein kinase (MAPK) mediated the antiproliferative effect of IL-1 partially through the downregulation of activity and protein level of ornithine decarboxylase (ODC). In this study, we investigated the role of CCAAT/enhancer-binding protein (C/EBP) homologous protein (CHOP), one of the p38 MAPK target transcriptional factors. The mRNA level of CHOP was not affected by IL-1 treatment in A375-6 cells. Unexpectedly, CHOP was constitutively phosphorylated, and IL-1 or p38 MAPK inhibitor, SB203580, did not affect the phosphorylation level. However, A375-6 cells exhibited enhanced sensitivity to IL-1 by transfecting CHOP expression plasmid and reduced sensitivity to IL-1 by antisense CHOP mRNA expression plasmid. Furthermore, CHOP appeared to regulate positively IL-6 production at the transcriptional level. The experiments using CHOP muteins revealed that dimerization ability - but not p38 MAPK-dependent phosphorylation or DNA binding activity - is important for the IL-6 inducing activity of CHOP. These results indicate that CHOP contributes to the IL-1 growth-inhibitory signal through augmenting IL-6 production.

Estimation of regional cerebral blood flow distribution in infants by near-infrared topography using indocyanine green

Near-infrared topography with indocyanine green was used to measure regional cerebral blood flow (rCBF) in the temporal lobes of infants. The mean rCBF in infants without neural abnormality was 14.5 +/- 3.1 ml/100 g/min, and the rCBFs in the fronto-temporal, temporal, and occipito-temporal regions were 15.1 +/- 3.9, 15.4 +/- 3.3, and 14.6 +/- 3.3 ml/100 g/min, respectively. Moreover, in one asphyxiated infant with infarction and one infant with subdural and intracerebellar hemorrhage, it was demonstrated that the area of defective blood flow could be detected as well as it can by SPECT. This technique makes it possible to estimate rCBF distribution in infants at the bedside. Thus, in the future, evaluation of various neonatal illnesses should be feasible.

Further reduction of radiation dose in helical CT for lung cancer screening using small tube current and a newly designed filter

A new aluminum filter, 5.8 mm thick at the center, was designed. The effective energy, exposure dose, absorbed dose, and noise were measured by using low-dose technique, very low-dose technique with a conventional filter, and very low-dose technique with a new filter on a chest phantom. Accuracy of very low-dose computed tomography (CT) with a new filter was compared against standard helical CT in 40 patients and against chest radiography in 35 patients. Effective energies were 42.6 keV and 51.6 keV at a conventional filter and the new filter, respectively. Compared against 20mA with a conventional filter, exposure dose was reduced by 17%, and absorbed dose was equivalent, at 30 mA with the new filter. Noise was improved by 9%. Compared with standard helical CT, the sensitivity, specificity, and accuracy of very-low-dose helical CT were 100%, 88%, and 95%, respectively. Very-low-dose helical CT was found to be significantly superior to chest radiography in the detection of lung cancers. Using a smaller tube current and an appropriate filter allows a further reduction in radiation dose in helical CT for lung cancer screening.

Effects of metal ions on physicochemical properties and redox reactivity of phenolates and phenoxyl radicals: mechanistic insight into hydrogen atom abstraction by phenoxyl radical-metal complexes

Phenolate and phenoxyl radical complexes of a series of alkaline earth metal ions as well as monovalent cations such as Na+ and K+ have been prepared by using 2,4-di-tert-butyl-6-(1,4,7,10-tetraoxa-13-aza-cyclopentadec-13-ylmethyl)phenol (L1H) and 2,4-di-tert-butyl-6-(1,4,7,10,13-pentaoxa-16-aza-cyclooctadec-16-ylmethyl)phenol (L2H) to examine the effects of the cations on the structure, physicochemical properties and redox reactivity of the phenolate and phenoxyl radical complexes. Crystal structures of the Mg2+- and Ca2+-complexes of L1- as well as the Ca2+- and Sr2+-complexes of L2- were determined by X-ray crystallographic analysis, showing that the crown ether rings in the Ca2+-complexes are significantly distorted from planarity, whereas those in the Mg2+- and Sr2+-complexes are fairly flat. The spectral features (UV-vis) as well as the redox potentials of the phenolate complexes are also influenced by the metal ions, depending on the Lewis acidity of the metal ions. The phenoxyl radical complexes are successfully generated in situ by the oxidation of the phenolate complexes with (NH4)(2)[Ce4+(NO3)6] (CAN). They exhibited strong absorption bands around 400 nm together with a broad one around 600-900 nm, the latter of which is also affected by the metal ions. The phenoxyl radical-metal complexes are characterized by resonance Raman, ESI-MS, and ESR spectra, and the metal ion effects on those spectroscopic features are also discussed. Stability and reactivity of the phenoxyl radical-metal complexes are significantly different, depending on the type of metal ions. The disproportionation of the phenoxyl radicals is significantly retarded by the electronic repulsion between the metal cation and a generated organic cation (Ln+), leading to stabilization of the radicals. On the other hand, divalent cations decelerate the rate of hydrogen atom abstraction from 10-methyl-9,10-dihydroacridine (AcrH2) and its 9-substituted derivatives (AcrHR) by the phenoxyl radicals. On the basis of primary kinetic deuterium isotope effects and energetic consideration of the electron-transfer step from AcrH2 to the phenoxyl radical-metal complexes, we propose that the hydrogen atom abstraction by the phenoxyl radical-alkaline earth metal complexes proceeds via electron transfer followed by proton transfer.

The biocompatibility and osteoconductive activity of a novel hydroxyapatite/collagen composite biomaterial, and its function as a carrier of rhBMP-2

A hydroxyapatite/type I collagen (HAp/Col) composite, in which the hydroxyapatite nanocrystals align along the collagen molecules, has been prepared. The biocompatibility, osteoconductive activity, and efficacy as a carrier of recombinant human bone morphogenetic proteins (rhBMPs) of this novel biomaterial were examined. The composite material was implanted in the backs of Wistar rats, and specimens were collected for histological observations until week 24. In a second experiment, other samples of the composite material (5 x 5 x 10 mm3) were drilled and immersed in a solution of rhBMP-2 (0, 200, 400 microg/mL), and subsequently grafted in radii and ulnae in beagle dogs. As a control, three unfilled holes were left in one radius and ulna. X-ray images were prepared, and specimens collected for histological observation at weeks 8 and 12. Histological findings of the composites grafted in rats showed that the surface of the material was eroded as a result of macrophage infiltration. X-ray images and histological findings for the composites implanted in dogs support the idea that HAp/ Col has a high osteoconductive activity and is able to induce bone-remodeling units. In cases where the implants are grafted at weight bearing sites, treatment with rhBMP-2 at a dose of 400 microg/mL may be useful to shorten the time needed until bone union has occurred.

Evaluation of hepatocellular carcinoma after treatment with transcatheter arterial chemoembolization: comparison of Lipiodol-CT, power Doppler sonography, and dynamic MRI

BACKGROUND

The purpose of this study was to compare the ability of Lipiodol-computed tomography (CT), power Doppler (PD) sonography, and dynamic magnetic resonance imaging (MRI) in evaluating the therapeutic effect of transcatheter arterial chemoembolization (TACE) on hepatocellular carcinoma (HCC).

METHODS

TACE was performed by injecting an emulsion consisting of Lipiodol and a chemotherapeutic drug, followed by gelatin sponge particles, into 54 patients with 84 HCC lesions. Five to 7 days later, Lipiodol-CT, PD sonography, and dynamic MRI were performed. Findings from the three modalities were correlated with relapse within 1 year after TACE.

RESULTS

All lesions with blood flow on PD sonography or intratumoral enhancement on dynamic MRI relapsed regardless of the findings with Lipiodol-CT. None of the negatively enhanced lesions on dynamic MRI relapsed regardless of the Lipiodol-CT findings. However, the readers could not evaluate the contrast uptake in 14 lesions that were already hyperintense on the precontrast images. These cases were considered unsuitable for qualitative assessment and reduced the applicability of MRI to 83% of the examined lesions (70 of 84). Although PD sonography perfectly predicted relapse in superficial (0-5 cm from abdominal surface) lesions of the right hepatic lobe, blood flow in deep (>5 cm) or left lobe lesions was undetectable regardless of the occurrence of relapse. As a result, Lipiodol-CT displayed 76.0% sensitivity, 67.6% specificity, and 72.6% accuracy. The sensitivity, specificity, and accuracy of PD sonography were 34.0%, 100%, and 60.7%, respectively. In the 70 lesions in which evaluation was possible, dynamic MRI achieved 100% sensitivity, 100% specificity, and 100% accuracy.

CONCLUSION

Of the three modalities, dynamic MRI was the best for evaluating the efficacy of TACE in the treatment of HCC. We also found that superficial lesions of the right lobe are good candidates for PD sonography. However, high signals on precontrast MR images, motion artifacts, and ultrasonic attenuation remain key limitations.

Functional imaging of the brain in sedated newborn infants using near infrared topography during passive knee movement

Near infrared topography was used for functional imaging of the sensorimotor cortex of newborn infants during passive knee movement under sedated sleep. Contralateral knee movement caused a marked increase in oxyhemoglobin and total hemoglobin from the baseline values at almost all locations in the primary sensorimotor area of all neonates and a decrease in local deoxyhemoglobin in six of seven neonates. During ipsilateral knee movement, oxyhemoglobin and total hemoglobin showed slighter changes at a few locations, equal to 30% (mean) and 29% (mean) of the changes that occurred with contralateral stimulation, respectively. The mean times corresponding to maximal changes were 11.9 s for oxyhemoglobin and 19.1 s for deoxyhemoglobin, demonstrating that oxyhemoglobin has a much faster response than does deoxyhemoglobin.

Differences in transcutaneous bilirubin readings in Japanese term infants according to feeding method

BACKGROUND

Controversy has existed for many years over whether infant feeding methods are related to serum bilirubin concentrations during the first few days of life. Differences in initial jaundice patterns according to the feeding method until 72 h after birth have not been elucidated hitherto. The difference may become clear in Japanese neonates because jaundice shows a much higher peak bilirubin concentration and a later peak in Japanese neonates than in Caucasian neonates.

METHODS

In the present study, we investigated variations in the transcutaneous bilirubin reading (TcB) obtained within 72 h after birth among 177 breast-fed and 494 formula-fed healthy Japanese term neonates.

RESULTS

There was no difference between TcB in formula-fed and breast-fed infants until the first 30 h, after which time the rate of increase in TcB was lower in formula-fed infants. Among breast-fed neonates, a good linear regression between time after birth and TcB was maintained. Similarly, weight losses in breast-fed infants at 24-48 h and 48-72 h after birth were greater than those in formula-fed infants.

CONCLUSIONS

The jaundice pattern in Japanese neonates from 30 to 72 h after birth according to the feeding method was different from that in Caucasian neonates.

Concentration of progenitor cells collected from bone marrow fluid using a continuous flow cell separator

In ABO major incompatibility on bone marrow transplantation (BMT), red cells must be removed from collected marrow fluid to prevent hemolysis. We report the concentration of progenitor cells collected using a continuous flow cell separator (Cobe Spectra). The average volume of concentrated bone marrow was 132 +/- 47 ml and that of red cells included was 5.1 +/- 2.4 ml. The red cell removal rate was 97.6%. The recovery rate was 40.6% for total nuclear cells, 77.9% for mononuclear cells, 100% for CD34+ cells, and 93.9% for colony forming unit granulocyte-macrophage. Eighteen patients undergoing allogeneic BMT showed no signs of fever or hemolysis during concentrated marrow fluid transfusion. The recovery rate of progenitor cells was high, indicating sufficient recovery of hemopoiesis. This technique is applicable in ABO-incompatible BMT and in frozen-storage stem cells.

A study of induction of nerve regeneration using bioabsorbable tubes

A silicone tube (S-tube) was packed with CPLA (copolymer of poly-L-lactide) fibers (S-tube+CPLA) or collagen fibers (S-tube+fiber). Two types of tube were prepared from a collagen sheet (Col-tube) and a bioabsorbable atelocollagen membrane for guided tissue regeneration (GTR-tube). They were packed with collagen fibers or films (Col-tube+fiber, GTR-tube+fiber and GTR-tube+film). Bridge grafting (15 mm in length) was performed with these tubes in a rat sciatic nerve model. Specimens were harvested after 8 weeks. Minifascicles were formed in the open space between the CPLA fibers in the S-tube+CPLA group. Regenerated axons were also formed in the degenerated collagen fibers in the S-tube+Col group. Immunocytochemistry evaluation revealed that Schwann cells invaded the space in the absorbing collagen fibers. Histologic analysis of the regenerated axons in the groups with Col-tubes or GTR-tubes revealed that both the Col-tube and the GTR-tube packed with collagen fibers were effective in providing a scaffold for regenerating nerve tissue.