X-ray STM: Nanoscale elemental analysis & Observation of atomic track.

Scanning tunneling microscopy (STM) combined with brilliant X-rays from synchrotron radiation (SR) can provide various possibilities of original and important applications, such as the elemental analysis on solid surfaces at an atomic scale. The principle of the elemental analysis is based on the inner-shell excitation of an element-specific energy level "under STM observation". A key to obtain an atomic locality is to extract the element-specific modulation of the local tunneling current (not emission that can damage the spatial resolution), which is derived from the inner-shell excitation [1]. On this purpose, we developed a special SR-STM system and smart tip. To surmount a tiny core-excitation efficiency by hard X-rays, we focused two-dimensionally an incident beam having the highest photon density at the SPring-8.After successes in the elemental analyses by SR-STM [1,2] on a semiconductor hetero-interface (Ge on Si) and metal-semiconductor interface (Cu on Ge), we succeeded in obtaining the elemental contrast between Co nano-islands and Au substrate. The results on the metallic substrate suggest the generality of the method and give some important implications on the principle of contrast. For all cases of three samples, the spatial resolution of the analysis was estimated to be ∼1 nm or less, and it is worth noting that the measured surface domains had a deposition thickness of less than one atomic layer (Fig. 1, left and center).jmicro;63/suppl_1/i14-a/DFU045F1F1DFU045F1Fig. 1.(left) Topographic image and (center) beam-induced tip current image of Ge(111)-Cu (-2V, 0.2 nA). (right) X-ray- induced atomic motion tracks on Ge(111) that were newly imaged by the Xray-STM. On the other hand, we found that the "X-ray induced atomic motion" can be observed directly with atomic scale using the SR-STM system effectively under the incident photon density of ∼2 x10(15) photon/sec/mm(2) [3]. SR-STM visualized successfully the track of the atomic motion (Fig. 1, right), which enabled the further analysis on the mechanism of the atomic motion. It is worth comparing our results with past conventional thermal STM observations on the same surface [4], where the atomic motion was found to occur in the 2-dimensional domain. However, our results show the atomic track having a local chain distribution [3].The above mentioned results will allow us to investigate the chemical analysis and control of the local reaction with the spatial resolution of STM, giving hope of wide applications.

Fast microtomography using bright monochromatic x-rays.

A fast microtomography system for high-resolution high-speed imaging has been developed using bright monochromatic x-rays at the BL29XU beamline of SPring-8. The shortest scan time for microtomography we attained was 0.25 s in 1.25 µm effective pixel size by combining the bright monochromatic x-rays, a fast rotating sample stage, and a high performance x-ray imaging detector. The feasibility of the tomography system was successfully demonstrated by visualization of rising bubbles in a viscous liquid, an interesting issue in multiphase flow physics. This system also provides a high spatial (a measurable feature size of 300 nm) or a very high temporal (9.8 µs) resolution in radiographs.

Chemotactic activity for polymorphonuclear leukocytes: meconium versus meconium-stained amniotic fluid.

PROBLEM: Our previous study indicated that meconium-stained amniotic fluid (turbid AF) possessed a potent chemotactic activity for leukocytes, which may be dependent on interleukin-8. It is not known, however, whether meconium itself possesses this chemotactic activity. METHOD OF STUDY: Meconium samples were collected from mature neonates with and without turbid AF. A 5% meconium suspension in phosphate buffered saline was prepared and measured for its chemotactic activity for leukocytes using the blind well chamber technique. Concentrations of IL-8, TNFalpha and IL-1beta were also measured with ELISA. RESULTS: The number of leukocytes that migrated to the meconium suspension (35 +/- 27) was comparable with that of the clear AF (31 +/- 37), but was significantly lower than that of the turbid AF (184 +/- 62, P < 0.0001). The meconium suspension contained much lower levels of IL-8, TNFalpha and IL-1beta than the turbid AF. CONCLUSIONS: Meconium itself exhibits a lower chemotactic activity for polymorphonuclear leukocytes than turbid AF in vitro. The leukocyte chemotactic activity of turbid AF does not originate from meconium itself.

Isolated pericardial effusion and transient abnormal myelopoiesis in a fetus with Down's syndrome.

Isolated pericardial effusion was detected in a fetus at 34 weeks of gestation. A male infant weighing 2,044 g was born by cesarean section because of a non-assuring fetal heart rate pattern at 35 weeks of gestation. Transient leukocytosis (36,100/microl) with 49% blast cells was seen in this neonate. The infant's karyotype was 47, XY + 21. The pericardial effusion disappeared after treatment with prednisolone at a dose of 2 mg/kg/day. Hypothyroidism was subsequently found. Thus, the subject patient with Down's syndrome developed isolated pericardial effusion, transient abnormal myelopoiesis (TAM), and hypothyroidism. Because more than 20% of the infants with TAM and Down's syndrome develop acute nonlymphocytic leukemia in early childhood, he is being closely observed.

Onapristone (ZK299) blocks the suppressive effect of progesterone, but not that of dexamethasone, on inducible nitric oxide synthase gene expression and nitric oxide production in murine macrophages.

Suppressive effects of progesterone on inducible nitric oxide synthase (iNOS) protein expression and nitric oxide (NO) production in murine peritoneal macrophages in response to bacterial lipopolysaccharide (LPS) and the inhibition of the suppressive activity of progesterone by onapristone (ZK299), a synthetic progesterone inhibitor, were studied. Progesterone suppressed dose-dependently LPS-induced NO production by macrophages, and scarcely detectable expression of iNOS was seen in the macrophages. ZK299 liberated the macrophages from the inhibitory effect of progesterone. Although dexamethasone, a synthetic glucocorticoid, can potently suppress LPS-induced NO production by macrophages, ZK299 did not liberate the suppression by dexamethasone, suggesting that these two corticosteroids induce suppression through independent mechanisms. RT-PCR analysis showed that murine macrophages expressed no progesterone-receptor. These findings indicate that the inhibitory effect of progesterone occurs at least on the level of iNOS protein expression in the signaling pathway after the LPS-stimulus. Furthermore, our present data may suggest the existence of a yet unknown type of progesterone-receptor in murine macrophages, the binding to which is responsible for the inhibitory effect of progesterone, or that progesterone may act non-specifically on the macrophages without involvement of any receptor.

Catalytic asymmetrization of racemic dicyclopentadiene derivatives by using chiral copper(II) catalyst

Treatment of racemic dicyclopentadiene derivatives with tert-butyl peroxybenzoate in the presence of a catalytic amount of Cu(II)-tris- or bis-(oxazoline) complex directly gave optically active benzoyloxylated dicyclopentadiene derivatives, useful building blocks bearing multiple asymmetric centers, in a highly enantioselective manner (up to 87% ee).

Meconium-stained amniotic fluid exhibits chemotactic activity for polymorphonuclear leukocytes in vitro.

We have studied whether meconium-stained, turbid amniotic fluid (turbid AF) obtained during term pregnancy possesses chemotactic activity for polymorphonuclear leukocytes (PMNs) in the absence of clinically apparent infection. Eight samples of turbid AF were obtained from eight women who underwent a cesarean section (four emergency and four elective cesarean sections) in the absence of signs of clinical infection or fetal distress. Samples of clear AF obtained from nine women during an elective cesarean section served as a control. We used also a negative control (medium only) and a positive control containing 10 nM N-formyl-methionyl-leucyl-phenylalanine. The control or turbid AF specimen was placed in the lower compartment of a blind well chamber, and the PMN suspension was placed in the upper compartment. Following incubation, the number of PMNs that had migrated and passed through the filter to the AF was counted. The number of control PMNs that migrated to the turbid AF (200+/-59) was comparable to that of the positive (162+/-24) but significantly exceeded that of the clear AF (17+/-11; P < 0.0001) and of the negative control (25+/-9; P < 0.0001). Checkerboard assay indicated that the turbid AF exhibited a dose-dependent chemotactic activity for PMNs. The turbid AF contained higher levels of TNFalpha, IL-1beta and IL-8 than the clear AF. The concentration of IL-8 in the AF was correlated positively with the chemotactic activity of the AF (r = 0.733, P = 0.0005). Anti-human IL-8 antibody added in the turbid AF dose-dependently abolished the chemotactic activity of the turbid AF. It is concluded that meconium-stained AF is a chemoattractant for PMNs and that cytokines such as an IL-8 may be involved in this phenomenon.

Lipopolysaccharide (LPS)-induced intra-uterine fetal death (IUFD) in mice is principally due to maternal cause but not fetal sensitivity to LPS.

The present study deals with whether lipopolysaccharide (LPS)-induced intra-uterine fetal death (IUFD) is related to LPS-susceptibility of either mother or fetus and how LPS or LPS-induced TNF causes IUFD. LPS-susceptible C3H/HeN or -hypo-susceptible C3H/HeJ pregnant mice and the mice mated reciprocally with these mice were used on days 14 to 16 of gestation for experiments. All of fetuses in pregnant C3H/HeN mice mated with either C3H/HeN males [HeN(HeN)] or C3H/HeJ males [HeN(HeJ)] were killed within 24 hr when injected intravenously (i.v.) with 50 or 100 microg of LPS. On the other hand, the majority of fetuses in C3H/HeJ females mated with either C3H/HeJ males [HeJ(HeJ)] or C3H/HeN males [HeJ(HeN)] survived when injected i.v. with even 400 microg of LPS. These findings indicate that LPS-induced IUFD depends on the maternal LPS-responsiveness. LPS injected into mothers could pass through placenta to fetuses, since an injection with 125I-labeled LPS or IgG into pregnant mice resulted in considerable levels of radioactivity in fetuses as well as placenta. Cultured peritoneal macrophages derived from F1 mice of HeJ(HeN) or HeN(HeJ) mice, produced nitric oxide (NO) and tumor necrosis factor (TNF) in response to LPS, although the levels of NO and TNF were lower in comparison with those of C3H/HeN macrophage cultures, suggesting a possibility that the fetus as well as F1 cells might be responsible to LPS. LPS-induced IUFD was not blocked by treatment with anti-TNF antibody which inhibited LPS-induced TNF production in pregnant females, although an injection of recombinant TNFalpha instead of LPS could induce IUFD, suggesting that the cause of IUFD cannot be attributed to mother-derived TNF alone. The roles of LPS passed through placenta and LPS-induced mediators on IUFD were discussed.

Refraction-enhanced x-ray imaging of mouse lung using synchrotron radiation source.

The low divergent x-ray beam from the third-generation synchrotron radiation source such as SPring-8 enables us to observe refraction of x rays that is in the range of microradians. Under an experimental condition for which ray optics is a good approximation, we found that the refraction produces a high-contrast projection image of a mouse when it was recorded at 6.5 m behind the specimen. Especially, the lung is visualized far better than with the conventional imaging which utilizes absorption of x rays. This is a promising new technique for the diagnosis of diseases in the human lung with a low radiation dose.

Relation between gestational thrombocytopenia and the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome).

OBJECTIVE: To define the clinical features of gestational thrombocytopenia and to determine its relationship to the syndrome of hemolysis, elevated liver enzymes, and low platelet count (HELLP syndrome). STUDY DESIGN: Retrospective cohort study. We reviewed the records of 24 women with gestational thrombocytopenia among 637 nonpreeclamptic women who had serial determinations of the platelet count during pregnancy between 1992 and 1995. Gestational thrombocytopenia was defined as an antenatal gradual decline in the platelet count to <150 x 10(9)/l in nonpreeclamptic women. The control group consisted of 213 nonpreeclamptic women whose platelet counts were > or = 150 x 10(9)/l at -3 to 0 days from delivery and in whom the perinatal serum level of aspartate transaminase (AST) had been determined. RESULTS: The platelet count decreased gradually, from 210+/-31 x 10(9)/l at < 13 weeks' gestation to 127+/-24 x 10(9)/l at -3 to 0 days from delivery, in the 24 women with gestational thrombocytopenia. The platelet count was 251+/-62 x 10(9)/l at -3 to 0 days from delivery in the 213 control women. The serum level of AST was elevated perinatally in 5 (21%) of 24 women with gestational thrombocytopenia compared with 6 (2.8%) of the 213 control subjects (p < 0.001). There had been 28 previous term or near-term pregnancies among 17 women with gestational thrombocytopenia, 14 of which were complicated by gestational thrombocytopenia or a decline in the platelet count by > 50 x 10(9)/l; 1 pregnancy was associated with the features typical of the HELLP syndrome. CONCLUSION: Gestational thrombocytopenia may be a risk factor for the development of the HELLP syndrome and is likely to recur in subsequent pregnancies.

Standard transport channels of X-ray beamlines at SPring-8.

SPring-8 is constructing most of its beamlines using a combination of standardized components. The structures of the beamlines are also standardized according to the light-source characteristics. Specifications of components as well as the unified method of assembly and alignment are described.

Redistribution of phospholipid/Ca2+-dependent protein kinase in mast cells activated by various agonists.

Three types of agonists; receptor-mediated concanavalin A), direct (phorbol ester), and membrane-perturbing (compound 48/80), elicit histamine secretion from rat peritoneal mast cells. We tested whether activation of the mast cells by these agents is accompanied by subcellular redistribution of protein kinase C. Phorbol ester treatment predictably caused a profound decrease of phospholipid/Ca2+-dependent histone kinase activity in the cytosol and a concomitant increase of [3H]PMA-binding capacity in the membrane fraction, in a time- and concentration-dependent manner. Similar, but less marked effects were observed with stimulations by concanavalin A and compound 48/80. When mast cells labeled with [32P] and then stimulated with the agents, phosphorylation of a 50,000-Dalton protein was enhanced in the membrane fraction. These results suggest that protein kinase C may play a role in mast cell activation through phosphorylation of the membrane protein.

Novel flushing provoked by volatile anesthetics in Mastomys natalensis bearing a transplantable substrain of gastric carcinoid that predominantly secretes serotonin.

A tumor substrain secreting a large amount of serotonin [5-hydroxytryptamine (5-HT); CAS: 50-67-9; 3-(2-amino-ethyl)indol-5-ol] and a minute amount of histamine (CAS: 51-45-6) has been isolated from the previously established strain of transplantable gastric carcinoid of Mastomys (Praomys) natalensis secreting both histamine and 5-HT. Mastomys bearing a large growing transplant and excreting a large amount of 5-hydroxy-indoleacetic acid [(5-HIAA) CAS: 54-16-0] were associated often with reddening of the nose, lower lip, auricles, hands, and feet. Soon after the animals were anesthetized by ether or other volatile anesthetics, the tinges of red of the above-mentioned exposed parts abruptly turned bright red and rapidly spread over the neck, upper chest, and epigastric area. The reddening was transient, lasting 1.5-5 minutes, thereby fulfilling the criteria of flushing. The severity of ether-provoked flushing in tumor-bearing Mastomys paralleled the urinary excretion levels of 5-HIAA. The ether-provoked flushing was prevented completely by sc injection of either ketanserin (150 micrograms) or somatostatin (20 micrograms). The same ether-provoked flushing as found in tumor-bearing Mastomys could be reproduced in normal ones by constant infusion of 20 mg 5-HT/kg/24 hours (i.e., doses comparable to those released from a transplanted tumor) through an osmotic minipump implanted subcutaneously.

[Histopathologic observation of anti-tumor effects of bleomycin and irradiation on cancers of the tongue].

Nine cases of squamous cell carcinoma of the tongue were treated by either intramuscular or local injections of total 60 to 200 mg of Bleomycin (BLM), and 7 cases by total doses of 1,200 to 5,320 rads of irradiation, followed by surgical removal of primary neoplasm. The histologic examination of the biopsied and surgical specimens from each case was done focussing on the antitumor effect of both treatments. In the cases with keratinizing component more than 25% in the biopsy specimens, the earliest change due to BLM was vacuolar degeneration of proliferating cells either at the base of superficial cancer epithelia or at the periphery of invading cancer foci. When the proliferating cancer cells disappeared, an appearance of invading cancer foci resembled to that of ectopic islands of normal squamous epithelium. These foci of differentiated squamous cell carcinoma gradually underwent morphological change into the so-called cancer pearls. Finally, the cancer pearls degenerated, leaving foreign bodies consisting of concreted keratin. The stromal reaction was characterized by the formation of granulation tissues accompanying significant numbers of foreign body giant cells. In the cases of lingual carcinoma with poor squamous differentiation, these processes were indistinct. Instead, the proliferating anaplastic cancer cells were markedly reduced and the remaining cancer cells transformed into large bizarre cells, probably at degenerative stage. On the histologic level, irradiation showed essentially similar antitumor effect to BLM, except for the rapid formation of concreted keratin bodies accompanying more abundant foreign body giant cells and the presence of irregular granulation tissues at different stages. We concluded that both BLM and irradiation had a powerful antitumor action on squamous cell carcinoma of the tongue. It is necessary, however, to establish an appropriate treatment modality through the more detailed histologic evaluation of a number of lingual cancer patients in consideration of the natural history of this neoplasm.