Modern precipitation of hydrogenetic ferromanganese minerals during on-site 15-year exposure tests.

Redox-sensitive metallic elements, Mn and Fe, are oxidized in deep sea waters and form abundant ferromanganese crusts and nodules on the world's ocean floors at ultraslow rates of growth. This process of oxidation and the mechanism of precipitation are yet unknown. In this paper, the results of the first successful, long-term, on-site experiment of mineral precipitation that ascertains modern, ongoing hydrogenetic deposition of oxide materials from normal seawaters at water depths of 900-4500 m of geologically active and inactive environments are presented. We succeeded in the in-situ precipitation experiment on the sea floor and characterized the precipitates using high-resolution and submicron-scale chemical, mineralogical, and structural analyses. The installed artificial plates of glass, ceramics, and plastic yielded spread-out particles of sizes varying from one to a few micrometers in diameter, of coccoid-like irregular shapes, with a maximum of 1,000-10,000 individual particles/mm2/year after 12-15 years of exposure. The results indicated a continuous substantial growth of the hydrogenetic minerals if both Mn and Fe are supplied to the bottom waters. The mineralogical, chemical, and structural properties of the precipitates are similar to those of the natural precipitates on the seabed that are made up of hydrogenetic ferromanganese crusts and nodules, together with settling sediments, suspended hydrothermal particles, or microbial precipitates from cultivated Mn-oxidizing bacteria. Our work presents new realistic insight into proposed genetic models of marine hydrogenetic ferromanganese deposits in modern diverse ocean environments.

Urinary excretion of uric acid, allantoin, and 8-OH-Deoxyguanosine in uricase-knockout mice.

Although uricase-knockout (Uox KO) mice are reported to develop uric acid (UA) nephropathy, those that mature without severe nephropathy could be useful for research into purine metabolism in humans. In this study, we measured the urinary excretion of creatinine, UA, allantoin, and 8-hydroxy-2'-deoxyguanosine (8-OHdG) collected from Uox KO mice housed in metabolic cages. UA and allantoin were determined using liquid chromatography-mass spectrometry and creatinine and 8-OHdG were measured with a commercial kit. Uox KO mice excreted significantly higher levels of UA than wild-type mice (C57BL/6), while the excretion of allantoin was significantly lower. Urinary allantoin was detected in Uox KO mice despite a lack of uricase, which is the same as in humans. In contrast to the elevated levels of UA, the daily excretion of 8-OHdG, an oxidative stress marker, was lower in Uox KO mice. UA is thought to act as an anti-oxidizing agent in humans; thus, these results show that Uox KO mice are potential animal models for research into human purine metabolism.

Trend of stroke incidence in a Japanese population: Takashima stroke registry, 1990-2001.

BACKGROUND: In Japan, stroke mortality and incidence started to decline during the 1960s. The recent unfavourably diverging trends in risk factors make it uncertain whether the decline will continue. Few comprehensive stroke registries of long research duration exist in Japan to illustrate the trends in stroke incidence. OBJECTIVE: We examined 12-year stroke registration data to evaluate the current trend in a Japanese population. METHODS: Data were obtained from the Takashima Stroke Registry, covering approximately 55 000 residents of Takashima County in central Japan. We calculated the age-adjusted stroke incidence rates (/100 000 person-years) and 95% confidence intervals for 1990-1992, 1993-1995, 1996-1998, and 1999-2001. We applied the direct method to adjust for the age distribution among the four periods. The incidence time trend was determined by calculating the average annual change across the study years using negative binomial regression analysis. RESULTS: There were 1453 (men: 771 and women: 682) registered first-ever stroke cases during 1990-2001. The diagnosis was established by neuro-imaging in 93.6% of the cases. The average age was 69.4 years in men and 74.2 years in women. The age-adjusted incidence rates of stroke across the four observation periods were 143.1 (confidence interval: 127.4-158.8) in 1990-1992, 147.4 (confidence interval: 131.9-162.8) in 1993-1995, 120.4 (confidence interval: 106.7-134.0) in 1996-1998, and 122.9 (confidence interval: 109.6-136.2) in 1999-2001. The stroke incidence across the study years showed an insignificant time trend, with an average annual change of -0.33% (confidence interval: -2.44 to 1.78) per year. Similar trends were observed for both men and women and stroke subtypes. CONCLUSIONS: The previously reported declining trend in stroke incidence may have levelled off or slowed down considerably in the Japanese population.

Novel risk stratification of patients with neuroblastoma by genomic signature, which is independent of molecular signature.

Human neuroblastoma remains enigmatic because it often shows spontaneous regression and aggressive growth. The prognosis of advanced stage of sporadic neuroblastomas is still poor. Here, we investigated whether genomic and molecular signatures could categorize new therapeutic risk groups in primary neuroblastomas. We conducted microarray-based comparative genomic hybridization (array-CGH) with a DNA chip carrying 2464 BAC clones to examine genomic aberrations of 236 neuroblastomas and used in-house cDNA microarrays for gene-expression profiling. Array-CGH demonstrated three major genomic groups of chromosomal aberrations: silent (GGS), partial gains and/or losses (GGP) and whole gains and/or losses (GGW), which well corresponded with the patterns of chromosome 17 abnormalities. They were further classified into subgroups with different outcomes. In 112 sporadic neuroblastomas, MYCN amplification was frequent in GGS (22%) and GGP (53%) and caused serious outcomes in patients. Sporadic tumors with a single copy of MYCN showed the 5-year cumulative survival rates of 89% in GGS, 53% in GGP and 85% in GGW. Molecular signatures also segregated patients into the favorable and unfavorable prognosis groups (P=0.001). Both univariate and multivariate analyses revealed that genomic and molecular signatures were mutually independent, powerful prognostic indicators. Thus, combined genomic and molecular signatures may categorize novel risk groups and confer new clues for allowing tailored or even individualized medicine to patients with neuroblastoma.

Discovery of novel aldose reductase inhibitors using a protein structure-based approach: 3D-database search followed by design and synthesis.

Aldose reductase (AR) has been implicated in the etiology of diabetic complications. Due to the limited number of currently available drugs for the treatment of diabetic complications, we have carried out structure-based drug design and synthesis in an attempt to find new types of AR inhibitors. With the ADAM&EVE program, a three-dimensional database (ACD3D) was searched using the ligand binding site of the AR crystal structure. Out of 179 compounds selected through this search followed by visual inspection, 36 compounds were purchased and subjected to a biological assay. Ten compounds showed more than 40% inhibition of AR at a 15 microg/mL concentration. In a subsequent lead optimization, a series of analogues of the most active compound were synthesized based on the docking mode derived by ADAM&EVE. Many of these congeners exhibited higher activities compared to the mother compound. Indeed, the most potent, synthesized compound showed an approximately 20-fold increase in inhibitory activity (IC(50) = 0.21 vs 4.3 microM). Furthermore, a hydrophobic subsite was newly inferred, which would be useful for the design of inhibitors with improved affinity for AR.

Striped iron zoning of olivine induced by dislocation creep in deformed peridotites.

Deformation of solid materials affects not only their microstructures, but also their microchemistries. Although chemical unmixing of initially homogeneous multicomponent solids is known to occur during deformation by diffusion creep, there has been no report on their chemical zoning due to deformation by dislocation creep, in either natural samples or laboratory experiments. Here we report striped iron zoning of olivine ((Mg,Fe)2SiO4) in deformed peridotites, where the iron concentration increases at subgrain boundaries composed of edge dislocations. We infer that this zoning is probably formed by alignment of edge dislocations dragging a so-called Cottrell 'atmosphere' of solute atoms (iron in this case) into subgrain boundaries during deformation of the olivine by dislocation creep. We have found that the iron zoning does not develop in laboratory experiments of high strain rates where dislocations move too fast to drag the Cottrell atmosphere. This phenomenon might have important implications for the generation of deep-focus earthquakes, as transformation of olivine to high-pressure phases preferentially occurs in high-iron regions, and therefore along subgrain boundaries which would be preferentially aligned in plastically deformed mantle peridotites.

Identification and characterization of a 500-kb homozygously deleted region at 1p36.2-p36.3 in a neuroblastoma cell line.

Loss of heterozygosity of the distal region of chromosome 1p where tumor suppressor gene(s) might harbor is frequently observed in many human cancers including neuroblastoma (NBL) with MYCN amplification and poor prognosis. We have identified for the first time a homozygously deleted region at the marker D1S244 within the smallest region of overlap at 1p36.2-p36.3 in two NBL cell lines, NB-1 and NB-C201 (MASS-NB-SCH1), although our genotyping has suggested the possibility that both lines are derived from the same origin. The 800-kb PAC contig covering the entire region of homozygous deletion was made and partially sequenced (about 60%). The estimated length of the deleted region was 500 kb. We have, thus far, identified six genes within the region which include three known genes (DFF45, PGD, and CORT) as well as three other genes which have been reported during processing our present project for the last 3(1/2) years (HDNB1/UFD2, KIAA0591F/KIF1B-beta, and PEX14). They include the genes related to apoptosis, glucose metabolism, ubiquitin-proteasome pathway, a neuronal microtubule-associated motor molecule and biogenesis of peroxisome. At least three genes (HDNB1/UFD2, KIAA0591F/KIF1B-beta, and PEX14) were differentially expressed at high levels in favorable and at low levels in unfavorable subsets of primary neuroblastoma. Since the 1p distal region is reported to be imprinted, those differentially expressed genes could be the new members of the candidate NBL suppressor, although RT-PCR-SSCP analysis has demonstrated infrequent mutation of the genes so far identified. Full-sequencing and gene prediction for the region of homozygous deletion would elucidate more detailed structure of this region and might lead to discovery of additional candidate genes. Oncogene (2000) 19, 4302 - 4307

Neocortical origin and tangential migration of guidepost neurons in the lateral olfactory tract.

The early-generated neurons designated as lot cells specifically mark the future site of the lateral olfactory tract (LOT) and guide LOT axons. We investigated the mechanism of how lot cells develop and get localized in the LOT position. Lot cells differentiated from neuroepithelial cells in all regions of the neocortex but not from those in the ganglionic eminence in culture. Cell tracing analyses demonstrated that lot cells generated from the neocortex subsequently followed a tangential migration stream ventrally toward the LOT position. Mutant mouse embryos lacking the function of transcription factor Gli3 showed disturbances of the migration stream and translocation of lot cells in the dorsal telencephalon. These results reveal a new type of neuronal migration in the telencephalon and introduce an unexpected dramatic feature of the earliest regionalization of the telencephalon.

Identification of the full-length KIAA0591 gene encoding a novel kinesin-related protein which is mapped to the neuroblastoma suppressor gene locus at 1p36.2.

The distal region of a short arm of chromosome 1p is frequently deleted in many human cancers including neuroblastoma (NBL), in which it has been narrowed down to the smallest region of overlap between D1S244 and D1S214 (approximately 7 cM). During the search for the candidate tumor suppressor genes mapped within the region, we found the KIAA0591 gene which encoded a new human kinesin-related protein with a homology to human axonal transporter of synaptic vesicles (ATSV). The kinesin is an intracellular motor protein and often associated with neuronal differentiation and survival. Here we identified a complete open reading frame of the KIAA0591 gene by screening a cDNA library derived from human substantia nigra. The KIAA0591 protein contains a possible pleckstrin homology (PH) domain at its carboxy-terminus. However, it did not possess a force-generating motor domain which is well conserved among kinesin superfamily members (KIFs). Northern blot analysis demonstrated that KIAA0591 mRNA was preferentially expressed in both adult and fetal brains, kidney, skeletal muscle and pancreas. KIAA0591 was expressed in favorable NBLs at higher levels than in unfavorable NBLs, although RT-PCR SSCP analysis showed no mutation within the coding region of the KIAA0591 gene, when 8 neuroblastoma tissues and 15 neuroblastoma-derived cell lines were examined. Thus, the full-length KIAA0591 gene may be a novel member of human KIF superfamily which lacks motor domain and might function as a tumor suppressor in an epigenetic but not a classic Knudson's manner.

Gastric exclusion for unresectable gastric cancer.

BACKGROUND/AIMS: Conventional gastrojejunostomy is sometimes performed for unresectable gastric cancer, but it is not fully effective. To improve the patient's quality of life, we performed gastric exclusion. METHODOLOGY: Twenty-seven patients who received gastrojejunostomy (11 conventional, 16 gastric exclusion) were retrospectively examined as to post-operative quality of life and outcome. RESULTS: No stomal strictures were observed, and gastrointestinal bleeding was significantly reduced in the gastric exclusion group. These advantages enabled the gastric exclusion group to achieve better quality of life, as indicated by longer oral intake (244 days vs. 98 days) and home stay (211 days vs. 91 days). The prognosis also improved. The 50% survival period in the gastric exclusion group was 229 days, whereas, that of the conventional gastrojejunostomy group was 131 days. CONCLUSIONS: The quality of life and prognosis of the gastric exclusion group significantly improved, and we believe that the improvement of the quality of life yielded a better prognosis. We recommend gastric exclusion as a standard procedure for unresectable gastric cancer.

Successful simultaneous operation of concomitant early gastric cancer, transverse colon cancer, and a common iliac artery aneurysm.

In an 83-year-old Japanese man, concomitant bleeding colon cancer, early gastric cancer, and an expanding right common iliac artery aneurysm were evident. The patient underwent an artificial graft implantation, partial gastrectomy, and transverse colectomy, simultaneously. To protect against graft infection, the aneurysm was resected first, and then the retroperitoneum was tightly closed to isolate the graft from the peritoneal cavity. The postoperative course was uneventful, except for symptoms of temporary delirium. Recently, simultaneous surgery for concomitant abdominal aortic aneurysms and early gastric cancer has been commonly performed in Japan because the contamination of the peritoneal cavity during a gastrectomy is thought to be less severe than that during lower abdominal surgery. However, the positive rate for bacterial culture in colorectal resections is virtually the same as that in gastrectomies. Moreover, the incidence of graft infection is substantially lower than the positive rate for bacterial culture in surgery for aneurysms. Some surgeons object to a simultaneous resection due to fear of graft infection, but even the presence of infectious organisms does not always result in graft infection. The present case illustrates the benefits of a simultaneous operation for both an aneurysm and gastrointestinal malignancy.

Induction and enhancement of stress proteins in a trichloroethylene-degrading methanotrophic bacterium, Methylocystis sp. M.

The responses of the trichloroethylene-degrading bacterium Methylocystis sp. M to six different water-pollutants, carbon starvation, and temperature-shock (heat and cold) were examined using 2-dimensional gel electrophoresis. Twenty-eight polypeptides were induced, and these stress-induced proteins were classified into three groups. Some of the chemically induced proteins were the same as those induced by carbon starvation and temperature-shock. Two of the polypeptides were induced by trichloroethylene. Trichloroethylene-stress protein synthesis required 1-2 h at a concentration of trichloroethylene that had no effect on growth. Furthermore, 25 stress-enhanced polypeptides were observed, and one of these was enhanced by trichloroethylene. Based on these results, we discuss applications of chemical-stress induction of proteins to establish effective bioremediation and bioassay by methanotrophs.

Synthesis, computer modeling and biological evaluation of novel protein kinase C agonists based on a 7-membered lactam moiety.

4-Hydroxymethyl-5a-methyl-1,3,4,5,5a beta,6,7,8,9,9a alpha-decahydro-2H-benz[d]azepin-2-ones (4-12), which were designed to mimic the biologically active conformation of teleocidins and benzolactams, were synthesized and evaluated for the ability to compete with [3H]phorbol 12,13-dibutyrate in a PKC delta binding assay. Among the compounds, 10-12 showed potent binding affinity, with inhibition constants (Ki) of low nanomolar order. Computational docking simulation also indicates that the relative positions of the hydrogen-bonding sites and hydrophobic regions of the compounds are well matched to the PKC delta binding site.

Indications for peripartum aortic pressure monitoring in Takayasu's disease. A patient with past history of intrapartum cerebral hemorrhage.

We describe a successful delivery by prophylactic cesarean section in a patient with Takayasu's disease who had a previous history of intrapartum cerebral hemorrhage during vaginal delivery. Aortography showed occlusion of the common carotid, subclavian and vertebral arteries on the left side, severe narrowing of the right subclavian artery, and moderate narrowing of the entire abdominal aorta. Blood pressure was managed by monitoring central aortic pressure at the thoracic aorta. During the peripartum course, we recommend monitoring the central aortic pressure in patients with Takayasu's disease in whom accurate blood pressure readings can not be obtained in any extremity.

Clarification of the binding mode of teleocidin and benzolactams to the Cys2 domain of protein kinase Cdelta by synthesis of hydrophobically modified, teleocidin-mimicking benzolactams and computational docking simulation.

Phorbol esters (12-O-tetradecanoylphorbol 13-acetate; TPA) and teleocidins are known to be potent tumor promoters and to activate protein kinase C (PKC) by binding competitively to the enzyme. The relationship between the chemical structures and the activities of these compounds has attracted much attention because of the marked structural dissimilarities. The benzolactam 5, with an eight-membered lactam ring and benzene ring instead of the nine-membered lactam ring and indole ring of teleocidins, reproduces the active ring conformation and biological activities of teleocidins. Herein we describe the synthesis of benzolactams with hydrophobic substituents at various positions. Structure-activity data indicate that the existence of a hydrophobic region between C-2 and C-9 and the steric factor at C-8 play critical roles in the appearance of biological activities. We also computationally simulated the docking of teleocidin and the modified benzolactam molecules to the Cys2 domain structure observed in the crystalline complex of PKCdelta with phorbol 13-acetate. Teleocidin and benzolactams fitted well into the same cavity as phorbol 13-acetate. Of the three functional groups hydrogen-bonding to the protein, two hydrogen-bonded with protein atoms in common with phorbol 13-acetate, but the third one hydrogen-bonded with a different protein atom from that in the case of phorbol 13-acetate. The model explains well the remarkable difference in activity between 5 and its analogue having a bulky substituent at C-8.

Proton transfer in benzyl alcohol dehydrogenase during catalysis: alternate proton-relay routes.

His51 in horse liver alcohol dehydrogenase (ADHE) has been proposed to act as a proton donor/acceptor in the NAD+/NADH-dependent oxidation/reduction of alcohol/aldehyde. The residue corresponding to His51 of ADHE is Val51 (Val45 in the protein sequence) in benzyl alcohol dehydrogenase (BADH) encoded by TOL plasmid pWW0. The 3-D structure of BADH modeled from the crystal structure of ADHE suggests that His47 (His41 in the protein sequence, corresponding to Arg47 in ADHE) of BADH would play the role of His51 in ADHE. To test this hypothesis, mutants of BADH, in which His47 was replaced by Gln(His47Gln) and/or Val51 was replaced by His (Val51His), were constructed. The kcat/K(m) value of the His47Gln mutant for benzyl alcohol was 125-fold lower than that of wild-type BADH, while the kcat/K(m) value of the His47Gln/Val51His double mutant was 12-fold higher than that of the His47Gln mutant. The kcat/K(m) value of the His47Gln mutant increased with increasing concentration of exogenous amines. These results suggest that His47 in wild-type BADH, exogenous amines in the His47Gln mutant, and His51 in the double mutant act as a general base catalyst during alcohol oxidation.

[Prognosis and preoperative imaging of patients with small hepatocellular carcinoma].

We conducted a retrospective study on the relation of the preoperative imaging patterns to the prognosis of patients with small HCC after hepatectomy. Forty patients with small HCC less than 2 cm in diameter without vascular invasion were enrolled in this study. There were no significant differences in the signal intensity of T1WI on MRI, and angiographic findings such as neo-vascularity or tumor stain. Ultrasonographical images of the internal of tumor were classified into two groups. Six cases with homogeneous pattern were significantly worse in cumulative survival rate than 28 cases with heterogeneous pattern (p = 0.0012). The same results were obtained with respect to limitation of cases treated by relative curative operation (p = 0.0041). It was concluded that histopathological grading and malignant potential of small HCC could be evaluated by classification of the pattern of internal ultrasonographical images, and complete locoregional therapy, and that intense course observation for cases with ultrasonographical homogeneous pattern would be important.

Natural (Mg,Fe)SiO3-ilmenite and -perovskite in the Tenham meteorite.

The minerals (Mg,Fe)SiO3-ilmenite and -perovskite were identified in the shock-induced veins in the Tenham chondritic meteorite. Both phases are inferred to have transformed from pyroxene at high pressures and temperatures by shock metamorphism. Columnar-shaped ilmenite grains, one of two types of morphologies, have a topotaxial relationship with neighboring pyroxene grains, indicating shear transformation. Granular-shaped perovskite grains showed a diffraction pattern consistent with orthorhombic perovskite, but these grains were not stable under the electron beam irradiation and became amorphous. The higher iron concentration in both phases compared with those experimentally reported may suggest their metastable transition from enstatite because of shock compression.

[Clinicopathological study on early recurrent hepatoma and its treatment].

Early Recurrence of Hepatoma: PCNA Labeling Index and DNA Ploidy Pattern Sixty-four cases of recurrent hepatocellular carcinoma (HCC) after hepatectomy were divided into two groups; E-group with recurrence within one year, and L-group with recurrence after 1 year. Clinicopathological features and surgical curability were the same in both groups. E-group had significantly higher positive rates of portal invasion, intrahepatic metastasis and rate of patients with more than 40% on PCNA labeling index. While the similar recurrence mode and the same treatment modalities were done, cumulative survival rates after recurrence in E-group had a poorer prognosis than L-group. These results suggest the possibility of lower response for the treatment on the recurrent lesion would be manifest in the E-group. New modalities for prevention of early recurrence of HCC after resection should be developed.

Lead discovery of inhibitors of the dihydrofolate reductase domain of Plasmodium falciparum dihydrofolate reductase-thymidylate synthase.

A three-dimensional structure model of the dihydrofolate reductase (DHFR) domain of the bifunctional DHFR-thymidylate synthase of Plasmodium falciparum was used as a basis for computational screening of commercially available compounds for candidate inhibitors. Compounds which can stably dock to the model with strong ionic hydrogen bonds via protonation by an aspartic acid residue at the bottom of the active site were identified through docking simulation. Among compounds thus identified, 21 were assayed for inhibitory activity towards the recombinant DHFR domain. Two compounds, 2-amino-1,4-dihydro-4,4,7,8-tetramethyl-s-triazino(1,2-a)benzimida zole and Trp-P-2, inhibited the recombinant P. falciparum DHFR domain with Ki values of 0.54 and 8.7 microM, respectively. Kinetic analysis showed that these compounds competitively inhibited the enzyme with respect to the substrate dihydrofolate. These findings support the validity of both the modeled structure and the docking results. Furthermore, these compounds serve as leads for developing new DHFR inhibitors, since their skeletal structures are different from any of known DHFR inhibitors. This paper also reveals a new biological activity of Trp-P-2, a potent mutagen.