Room-temperature ferromagnetism in transparent transition metal-doped titanium dioxide.

Dilute magnetic semiconductors and wide gap oxide semiconductors are appealing materials for magnetooptical devices. From a combinatorial screening approach looking at the solid solubility of transition metals in titanium dioxides and of their magnetic properties, we report on the observation of transparent ferromagnetism in cobalt-doped anatase thin films with theconcentration of cobalt between 0 and 8%. Magnetic microscopy images reveal a magnetic domain structure in the films, indicating the existence of ferromagnetic long-range ordering. The materials remain ferromagnetic above room temperature with a magnetic moment of 0.32 Bohr magnetons per cobalt atom. The film is conductive and exhibits a positive magnetoresistance of 60% at 2 kelvin.

Clinical course of abducens nerve palsy associated with skull base tumours.

BACKGROUND: The clinical course of abducens nerve palsy associated with skull base tumour is rarely reported. In this study, we examined the post-operative course of abducens nerve palsies associated with various skull base tumours. METHOD: Between January 2003 and December 2006, 240 patients with various skull base tumours underwent surgery at Kyushu University Hospital. Among them, nine patients presented with abducens nerve palsies (ten nerves) following surgery. The conditions included two pituitary adenomas, two trigeminal schwannomas and five meningiomas. We evaluated the function of the abducens nerves in these patients on admission, at discharge, and periodically in the outpatient clinic. FINDINGS: Four of the abducens nerve palsies already existed prior to surgery, and six of them developed post-operatively. In the four patients with pituitary adenomas and trigeminal schwannomas, all nerves were anatomically preserved and showed complete recovery of function within 6 months after surgery. In contrast, only two of the six palsies in patients with skull base meningiomas showed complete recovery. In three patients with petro-clival meningiomas, the abducens nerves were completely transected during surgery, and one was reconstructed using fibrin glue. This patient remarkably recovered from the abducens nerve palsy within 2 years. CONCLUSIONS: The abducens nerve palsies in pituitary adenomas and trigeminal schwannomas showed a better clinical course compared to those in skull base meningiomas. The abducens nerve palsies that occur with skull base meningiomas are less likely to recover. Nevertheless, it is important to preserve the nerves and to perform surgical repair if the nerve is transected.

Involvement of interleukin-8, vascular endothelial growth factor, and basic fibroblast growth factor in tumor necrosis factor alpha-dependent angiogenesis.

Tumor necrosis factor alpha (TNF-alpha) is a macrophage/monocyte-derived polypeptide which modulates the expression of various genes in vascular endothelial cells and induces angiogenesis. However, the underlying mechanism by which TNF-alpha mediates angiogenesis is not completely understood. In this study, we assessed whether TNF-alpha-induced angiogenesis is mediated through TNF-alpha itself or indirectly through other TNF-alpha-induced angiogenesis-promoting factors. Cellular mRNA levels of interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), basic fibroblast growth factor (bFGF), and their receptors were increased after the treatment of human microvascular endothelial cells with TNF-alpha (100 U/ml). TNF-alpha-dependent tubular morphogenesis in vascular endothelial cells was inhibited by the administration of anti-IL-8, anti-VEGF, and anti-bFGF antibodies, and coadministration of all three antibodies almost completely abrogated tubular formation. Moreover, treatment with Sp1, NF-kappaB, and c-Jun antisense oligonucleotides inhibited TNF-alpha-dependent tubular morphogenesis by microvascular endothelial cells. Administration of a NF-kappaB antisense oligonucleotide almost completely inhibited TNF-alpha-dependent IL-8 production and partially abrogated TNF-alpha-dependent VEGF production, and an Sp1 antisense sequence partially inhibited TNF-alpha-dependent production of VEGF. A c-Jun antisense oligonucleotide significantly inhibited TNF-alpha-dependent bFGF production but did not affect the production of IL-8 and VEGF. Administration of an anti-IL-8 or anti-VEGF antibody also blocked TNF-alpha-induced neovascularization in the rabbit cornea in vivo. Thus, angiogenesis by TNF-alpha appears to be modulated through various angiogenic factors, both in vitro and in vivo, and this pathway is controlled through paracrine and/or autocrine mechanisms.

Involvement of the transcription factor NF-kappaB in tubular morphogenesis of human microvascular endothelial cells by oxidative stress.

Oxygen radicals are induced under various pathologic conditions associated with neovascularization. Oxygen radicals modulate angiogenesis in cultured human microvascular endothelial cells by an unknown mechanism. Treatment of human microvascular endothelial cells for 15 min with 0.1 to 0.5 mM hydrogen peroxide (H2O2) or 100 U of tumor necrosis factor alpha per ml induced tubular morphogenesis in type I collagen gels. Gel shift assays with nuclear extracts demonstrated that H2O2 increases the binding activities of two transcription factors, NF-kappaB and AP-1, but not of Spl. Tumor necrosis factor alpha increased the binding activities of all three factors. A supershift assay with specific antibodies against JunB, JunD, and c-Jun (Jun family) showed that the antibody against c-Jun supershifted the AP-1 complex after H2O2 treatment. Coadministration of the antisense sequence of NF-kappaB inhibited H2O2-dependent tubular morphogenesis, and the antisense c-Jun oligonucleotide caused partial inhibition. The angiogenic factor responsible for H2O2-induced tubular morphogenesis was examined. Cellular mRNA levels of vascular endothelial growth factor and interleukin-8 (IL-8), but not those of transforming growth factor alpha, were increased after treatment with 0.5 mM H2O2. Coadministration of anti-IL-8 antibody inhibited tubular morphogenesis enhanced by H2O2, and IL-8 itself also enhanced the formation of tube-like structures. Treatment with antisense NF-kappaB oligonucleotide completely blocked H2O2-dependent IL-8 production by endothelial cells. The tubular morphogenesis of vascular endothelial cells after treatment with oxidative stimuli and its possible association with NF-kappaB and IL-8, is examined.

Expression of vascular endothelial growth factor and its possible relation with neovascularization in human brain tumors.

To examine which growth factors correlate with neovascularization in human brain tumors, the mRNA levels of transforming growth factor alpha, transforming growth factor beta, basic fibroblast growth factor, and vascular endothelial growth factor (VEGF) genes were determined by a Northern blot analysis in surgically obtained human gliomas and meningiomas. The vascular development was determined by counting the number of microvessels which were immunostained with von Willebrand factor. We normalized the growth factor mRNA levels versus the glyceraldehyde phosphate dehydrogenase mRNA level. In the 17 gliomas and 16 meningiomas examined, the mRNA of transforming growth factors alpha and beta, basic fibroblast growth factor, and VEGF were expressed at various levels. Among those 4 growth factors, the mRNA levels of VEGF, but not those of transforming growth factors alpha and beta and basic fibroblast growth factor, correlated significantly with vascularity in both gliomas (correlation coefficient r = 0.499; P < 0.05) and meningiomas (correlation coefficient r = 0.779; P < 0.001). These findings thus suggest that VEGF may be a positive factor in tumor angiogenesis in both human gliomas and meningiomas.

Cyclooxygenase-2 expression in human gliomas: prognostic significance and molecular correlations.

Cyclooxygenase (COX)-2, the inducible isoform of prostaglandin H synthase, has been implicated in the growth and progression of a variety of human cancers. Although COX-2 overexpression has been observed in human gliomas, the prognostic or clinical relevance of this overexpression has not been investigated to date. In addition, no study has analyzed the relationship between COX-2 expression and other molecular alterations in gliomas. Consequently, we examined COX-2 expression by immunohistochemistry in tumor specimens from 66 patients with low- and high-grade astrocytomas and correlated the percentage of COX-2 expression with patient survival. We also analyzed the relative importance of COX-2 expression in comparison with other clinicopathological features (age and tumor grade) and other molecular alterations commonly found in gliomas (high MIB-1 level, p53 alteration, loss of retinoblastoma (Rb) protein or p16, and high bcl-2 level). Kaplan-Meier analyses demonstrated that high COX-2 expression (>50% of cells stained positive) correlated with poor survival for the study group as a whole (P < 0.0001) and for those with glioblastoma multiforme in particular (P < 0.03). Cox regression analyses demonstrated that COX-2 expression was the strongest predictor of outcome, independent of all other variables. In addition, high COX-2 expression correlated with increasing histological grade but did not correlate with positive p53 immunostaining, bcl-2 expression, loss of p16 or retinoblastoma protein expression, or high MIB-1 expression. These findings indicate that high COX-2 expression in tumor cells is associated with clinically more aggressive gliomas and is a strong predictor of poor survival.

Comparison of the conversion rates of alpha-linolenic acid (18:3(n - 3)) and stearidonic acid (18:4(n - 3)) to longer polyunsaturated fatty acids in rats.

The delta 6-desaturase reaction is regarded to be the rate-limiting step in the conversion of linoleic acid (18:2(n - 6)) to arachidonic acid (20:4(n - 6)). The same is probably also the case with the conversion of alpha-linolenic acid (18:3(n - 3)) to eicosapentaenoic acid (20:5(n - 3)). However, there are very few in vivo studies that directly compared the conversion rate between 18:3(n - 3) and stearidonic acid (18:4(n - 3)), which is the delta 6-desaturated product of 18:3(n - 3). We compared this rate by feeding rats on a lipid-free diet supplemented with lard (9%, w/w) and 18:3(n - 3) ethyl ester (1%) diet or on a diet containing lard (9%) and 18:4(n - 3) ethyl ester (1%). A lard (10%)-supplemented diet was used as the control diet. The fatty acid compositions of total phospholipids, triglycerides and free fatty acids of both liver and plasma were measured after 1 or 3 weeks on different diets. The molar ratio of 20:5(n - 3) of most lipid fractions was about 2-fold higher in rats fed the 18:4(n - 3)-supplemented diet than in rats fed the 18:3(n - 3)-supplemented diet. 18:4(n - 3) was found in the liver lipid fraction in only a very small amount, even in the 18:4(n - 3)-supplemented groups. Thus, desaturation at C-6 is suggested to be the rate-limiting step in the conversion of 18:3(n - 3) to 20:5(n - 3).

Macrophage infiltration and heme oxygenase-1 expression correlate with angiogenesis in human gliomas.

Macrophages are key participants in angiogenesis. In this study on human brain tumors, we first investigated whether macrophage infiltration is associated with angiogenesis and malignant histological appearance. Immunostaining of macrophages and small vessels in resected glioma specimens indicated that numbers of infiltrating macrophages and small vessel density were higher in glioblastomas than in astrocytomas or anaplastic astrocytomas. Macrophage infiltration was closely correlated with vascular density in human gliomas. Heme oxygenase-1 (HO-1), which is the rate-limiting enzyme in heme catabolism, was also associated with activated macrophages. Expression of mRNA encoding HO-1 was correlated with macrophage infiltration and vascular density in human glioma samples. Infiltrating macrophages were positively stained with anti-HO-1 antibody by immunohistochemical analysis, and in situ hybridization for HO-1 indicated that HO-1 was expressed in infiltrating macrophages in gliomas. HO-1 gene may be a useful marker for macrophage infiltration as well as neovascularization in human gliomas.

Esophageal atresia with double tracheoesophageal fistula--a case report and review of the literature.

Esophageal atresia with double tracheoesophageal fistula (TEF) is a very rare anomaly, and the accurate preoperative diagnosis of proximal TEF is very difficult. This paper describes a baby girl who presented with esophageal atresia with double, proximal, and distal TEF. The distal TEF was diagnosed before operation, whereas the proximal TEF was found intraoperatively. Overlooking the presence of proximal TEF can lead to increased morbidity and mortality due to severe respiratory infection and the necessity of a second operation. Great care must therefore be taken to not overlook the presence of proximal TEF in patients with this anomaly.

A comparative study of apoptosis and proliferation in germinoma and glioblastoma.

Intracranial germinoma has a relatively good prognosis when treated with radiotherapy and chemotherapy, whereas glioblastoma has a poor prognosis irrespective of these treatments. Cell proliferation and cell death are opposing processes in tumor growth, with tumor progression reflecting the balance between proliferating and apoptotic cells. We investigated cell proliferation and cell death using MIB-1 staining and nick-end labeling in 13 germinomas in comparison with 11 glioblastomas. Expression of BAX and Bcl-2, which regulate apoptosis, were studied by immunohistochemistry. Although germinomas showed strong MIB-1 immunostaining similar to that seen in glioblastomas, germinomas included significantly more apoptotic cells. The ratio of apoptotic ratio to MIB-1 labeling index for germinomas was 72.9 +/- 36.9 (mean +/- SD), a higher, statistically significant ratio as compared with glioblastomas (14.5 +/- 11.2; P < 0.01). Furthermore, germinomas showed greater expression of BAX than did glioblastomas, while the expression of Bcl-2 was weak in both tumor types. A comparison of these apoptotic-related proteins showed that immunoreactivity for BAX was relatively higher in germinomas than in glioblastomas (P < 0.01), corresponding well to numerous apoptotic cells identified in germinoma tissues. These findings may account for the prognostic difference between germinoma and glioblastoma in the face of a similar proliferation potential according to MIB-1 immunostaining. The balance between cell proliferation and death should be considered when predicting outcomes in patients with intracranial tumors.

Anisatin modulation of the gamma-aminobutyric acid receptor-channel in rat dorsal root ganglion neurons.

1. Anisatin, a toxic, insecticidally active component of Sikimi plant, is known to act on the GABA system. In order to elucidate the mechanism of anisatin interaction with the GABA system, whole-cell and single-channel patch clamp experiments were performed with rat dorsal root ganglion neurons in primary culture. 2. Repeated co-applications of GABA and anisatin suppressed GABA-induced whole-cell currents with an EC50 of 1.10 microM. No recovery of currents was observed after washout with anisatin-free solution. 3. However, pre-application of anisatin through the bath had no effect on GABA-induced currents. The decay phase of currents was accelerated by anisatin. These results indicate that anisatin suppression of GABA-induced currents requires opening of the channels and is use-dependent. 4. Anisatin suppression of GABA-induced currents was not voltage dependent. 5. Picrotoxinin attenuated anisatin suppression of GABA-induced currents. [3H]-EBOB binding to rat brain membranes was competitively inhibited by anisatin. These data indicated that anisatin bound to the picrotoxinin site. 6. At the single-channel level, anisatin did not alter the open time but prolonged the closed time. The burst duration was reduced and channel openings per burst were decreased indicating that anisatin decreased the probability of openings.

Expression of matrix metalloproteinases 1 and 2 genes in a possible association with metastatic abilities of human pancreatic cancer cells.

We determined if any extracellular matrix degradative proteases were possibly associated with metastatic potentials of human pancreatic cancer cells. Liver metastatic abilities of six human pancreatic cancer cell lines were examined in nude mice, and divided into two high (2 lines) and low (4 lines) metastatic cell lines. Of six cell lines, matrix metalloproteinases-1 (MMP-1) was overexpressed in two high metastatic cell lines: and MMP-2 was overexpressed in one high metastatic cell line. Of the four low metastatic lines, two cell lines had relatively higher mRNA levels of tissue inhibitors of metalloproteinases-3 (TIMP-3). MMP activities due to MMP-1 and MMP-2 might be positively associated with liver metastasis of pancreatic cancer cells. Moreover, expression of TIMP-3 might be partly involved in the low metastatic potentials of pancreatic cancer.

Fenitroxon insensitive acetylcholinesterases of the housefly, Musca domestica associated with point mutations.

The cDNA of AChE in the housefly, Musca domestica, was sequenced and individual flies were genotyped by this gene in an inhibition assay of AChE activity with an organophaspate, fenitroxon. Mutations at Gly(342) and Tyr(407), which are reportedly conserved in resistant strains of Drosophila, were associated with the insensitivity to fenitroxon. Two other mutations, Ile(162) and Val(260), did not have an apparent effect on insensitivity. However, the four mutations are located in the active site of the enzyme, and therefore the non-neutral mutations in this gene are considered to cause the insensitivity of AChE in the development of insecticide resistance of the housefly.

Molecular cloning, nucleotide sequence and gene expression of a cytochrome P450 (CYP6F1) from the pyrethroid-resistant mosquito, Culex quinquefasciatus Say.

To analyze cytochrome P450s in the southern house mosquito, Culex quinquefasciatus, we quantified the content of P450s and b5 in larval microsomes of guts and carcasses. Results indicated that content was 30 times higher in guts than in carcasses. A conserved region in the alignment of insect P450 family 6 (CYP6) proteins served as a guide for the synthesis of degenerate oligonucleotide primers to clone P450 cDNAs. Primers were used in the reverse transcription-polymerase chain reaction (RT-PCR) of gut mRNA from 4th-instar larvae of the permethrin-susceptible or resistant C. quinquefasciatus. PCR products of ca. 250 base pairs (bp) were cloned, and nucleotide sequences of 35 clones from susceptible and 28 from resistant strains determined. Alignment of the deduced amino acid sequences from these clones showed them to be classifiable into six isoforms. We next screened a cDNA clone (CYP6F1) from a gut cDNA library and determined the nucleotide sequence. Northern blot analysis showed that the CYP6PF1 gene in the permethrin-resistant strain appeared to be expressed more strongly than in the susceptible strain. The deduced amino acid of CYP6F1 showed that it has conserved domains of a membrane-anchoring signal, reductase binding sites, a heme-binding site, ETLR motif and substrate recognition sites in P450s. Phylogenetic analysis showed that CYP6F1 is strongly related to CYP6D1 involved in pyrethroid detoxification.

Dieldrin and picrotoxinin modulation of GABA(A) receptor single channels.

The insecticide dieldrin is known to suppress the GABA(A) receptor-channel complex in a manner similar to that of picrotoxin. To elucidate the more detailed mechanisms of dieldrin and picrotoxin interactions with the GABA system, single-channel patch clamp experiments were performed using rat dorsal root ganglion neurons in primary culture. Dieldrin did not alter the open time distribution and mean current amplitude or the distribution of burst duration and the mean burst duration. However, the mean closed time was prolonged indicating that dieldrin decreased the channel open probability. Previous studies have demonstrated that dieldrin and picrotoxin share the common binding site on the GABA receptor. Thus, the effects of picrotoxinin on the GABA(A) receptor single channels were also examined. Dieldrin and picrotoxinin had similar effects at the single-channel level. These changes of single-channel parameters explain the suppressive effects of these chemicals on GABA-induced whole-cell currents.

Intracellular signal transduction of PBAN action in lepidopteran insects: inhibition of sex pheromone production by compactin, an HMG CoA reductase inhibitor.

Pheromone biosynthesis activating neuropeptide (PBAN) regulates sex pheromone production in the pheromone glands of many species of female moths. In order to probe the biochemical steps as well as underlying mechanisms regulated by PBAN, we have tested the effect of chemicals on sex pheromone production by using an in vitro assay. Among the chemicals we tested here, compactin, a specific 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase inhibitor, clearly inhibited the pheromone biosynthesis in the silkworm, Bombyx mori, and the common cutworm, Spodoptera litura. Since the activation of HMG CoA reductase occurs by dephosphorylation mediated by a specific phosphatase and the biochemical step regulated by PBAN in bombykol biosynthesis is similar to the one catalyzed by HMG-CoA reductase in cholesterol biosynthesis, the present results support the idea that phosphoprotein phosphatase has a significant role to regulate bombykol production in the intracellular transduction of PBAN action in B. mori.

Angiogenesis as a new target for cancer treatment.

Neovascularization is often required for rapid growth of solid tumors and also limits vascular metastasis of tumor cells. Neovascularization-targeting agents are a recent innovation that may be a novel means of anticancer therapy. These antiangiogenic drugs have been developed by targeting cell proliferation of vascular endothelial cells, basement-membrane-degrading enzymes, angiogenic factors/receptors, extracellular matrix, angiogenesis signaling, and cell-cell/cell-matrix interactions. In this report, we describe how tumor angiogenesis occurs and how antiangiogenic agents are developed.

Serum apoprotein A-I and A-II levels in liver diseases and cholestasis.

Serum apoprotein A-I and A-II levels were determined by electroimmunoassay in patients with liver diseases and cholestasis. Significant decreases in apoprotein A-I and A-II levels were observed in such patients. The decreases were especially pronounced in the early phase of acute hepatitis and cholestasis. The decreases in A-II levels were more prominent than the decreases in A-I in severe hepatic dysfunction or cholestasis. Accordingly, the A-I/A-II ratio showed no change in the convalescent phase of acute hepatitis or chronic hepatitis but increased significantly in the early phase of acute hepatitis, cirrhosis of the liver, hepatoma, and cholestasis. The results suggested the existence of a high density lipoprotein with an abnormal apoprotein composition or a more profound decrease of HDL3 than of HDL2 in severe hepatocellular dysfunction of cholestasis.

Effect of retinoic acid on morphological changes of human pancreatic cancer cells on collagen gels: a possible association with the metastatic potentials.

Pancreatic carcinoma is an invasive and metastasizing type of malignancy. We established six pancreatic cancer cell lines from human pancreatic carcinomas, three highly metastatic lines (KP-1NL, KP-4, and SUIT-2) and three minimally metastatic lines (KP-2, KP-3, and BxPC-3). The three highly metastatic cell lines grew in a fibroblastoid pattern on collagen gels, whereas the three minimally metastatic cell lines grew in an epithelioid pattern under similar conditions. Western blot and Northern blot analyses indicated much higher levels of E-cadherin in the three minimally metastatic cell lines relative to the three highly metastatic cell lines. When the effect of all-trans-retinoic acid on the growth patterns of the three highly metastatic lines was examined, we observed a dramatic change from fibroblastoid to epithelioid growth in SUIT-2 cells. Although all six cell lines had comparable levels of retinoic acid receptor-gamma, retinoic acid receptor-beta was expressed only in SUIT-2 cells. Treating SUIT-2 cells with retinoic acid also induced the upregulation of E-cadherin expression. When SUIT-2 cells were treated with retinoic acid receptor-specific agonists, 13-cis-retinoic acid and Am555S, a morphological change from fibroblastoid to epithelioid growth was induced. Retinoic acid receptor-specific antagonists, LE135 and LE540, inhibited retinoic acid-induced change of the growth patterns. The effect of retinoic acid and its derivatives on the growth pattern was discussed in a possible association with their antimetastatic activities of pancreatic cancer.

Acquired Chiari I malformation and syringomyelia associated with bilateral chronic subdural hematoma. Case report.

The authors report a case of bilateral chronic subdural hematoma in a 25-year-old woman who had occipital and neck pain. Magnetic resonance imaging revealed progressive caudal descent of the cerebellar tonsils (acquired Chiari I malformation) and a large eccentric syrinx in the spinal cord from the C3-T7 levels. Spontaneous disappearance of the chronic subdural hematomas resulted in radiographic resolution of both lesions, as well as clinical improvement. Theories of syringomyelia formation, the relationship to acquired Chiari I malformation, and the implications of this case are discussed.