Precise spectroscopy of 167Er:Y2SiO5 based on laser frequency stabilization using a fiber laser comb.

Precise spectroscopy of the hyperfine level system of 167Er-doped Y2SiO5 was achieved in the frequency domain. By using an optical frequency comb to stabilize the light source frequency to an accuracy on the order of hertz on a long-term scale, Allan deviation < 10 Hz was achieved for an integration time of 180 s. As a result, spectral hole-burning experiments yielded a more accurate hole spectrum with a narrow homogeneous linewidth. The method opens the way to the straightforward exploration of relaxation mechanisms in the frequency domain by simple steady-state measurements.

Effect of structure and composition on optical properties of Er-Sc silicates prepared from multi-nanolayer films.

Polycrystalline Er-Sc silicates (Er(x)Sc(2-x)SiO5 and Er(x)Sc(2-x)Si2O7) were fabricated using multilayer nanostructured films of Er2O3/SiO2/Sc2O3 deposited on SiO2/Si substrates by RF- sputtering and thermal annealing at high temperature. RBS, TEM, GIXD, and PL results show the presence of Er(x)Sc(2-x)SiO5 with an emission peak at 1528 nm for annealing from 900 to 1100 °C, and Er(x)Sc(2-x)Si2O7 with an emission peak at 1537 nm for higher annealing temperature. The PL intensity of the Er(x)Sc(2-x)Si2O7 phase is five times stronger than that of the Er(x)Sc(2-x)SiO5 phase at 1250 °C. From PLE and PL spectra of Er(x)Sc(2-x)Si2O7 thin film, we schematically illustrate the Er³âº Stark energy levels of 4I(13/2) to 4I(15/2) manifolds due to the crystal field strength effect of Sc³âº. Temperature-dependent PL of the Er(x)Sc(2-x)Si2O7 phase exhibits a variation of the full-width at half-maximum (FWHM) from 1.1 to 2.3 nm. The narrow FWHM is due to the small ionic radii of Sc³âº, which enhance the crystal field strength affecting the optical properties of Er³âº ions located at the well-defined lattice sites of Sc silicate. A large excitation cross-section (σ(ex)) is equal to 3.0x10⁻²° cm² at λ(ex) = 1527.6 nm.

Cross talk between Smad transcription factors and TNF-alpha in intervertebral disc degeneration.

The transforming growth factor-beta (TGF-beta) and the tumor necrosis factor-alpha (TNF-alpha) families are known to play important roles in intervertebral disc degeneration (IVD). However, molecular interactions between the TGF-beta and TNF-alpha signaling pathways have yet to be elucidated. The purpose of this study was to analyze the expression patterns of Smad transcription factor signaling associated with IVDs with aging and to examine the modulation of Smad signaling by TNF-alpha in IVD cells using SD rats. According to these experimental results, BMP signals in the TGF-beta family were more likely to be a key factor in IVD degeneration by aging, and it was predicted that besides the involvement of catabolic factors like MMPs and ADAMS-TS, there may be a decrease in expression of anabolic factors through cross talk of signaling between TNF-alpha and TGF-beta pathway in pathogenesis of disc degeneration.

Locally administered low-dose alendronate increases bone mineral density during distraction osteogenesis in a rabbit model.

We investigated the effect of locally administered bisphosphonate on distraction osteogenesis in a rabbit model and evaluated its systemic effect. An osteotomy on the right tibia followed by distraction for four weeks was performed on 47 immature rabbits. They were divided into seven equal groups, with each group receiving a different treatment regime. Saline and three types of dosage of alendronate (low, 0.75 microg/kg; mid, 7.5 microg/kg and high 75 microg/kg) were given by systemic injection in four groups, and saline and two dosages (low and mild) were delivered by local injection to the distraction gap in the remaining three groups. The injections were performed five times weekly during the period of distraction. After nine weeks the animals were killed and image analysis and mechanical testing were performed on the distracted right tibiae and the left tibiae which served as a control group. The local low-dose alendronate group showed a mean increase in bone mineral density of 124.3 mg/cm(3) over the local saline group (analysis of variance, p < 0.05) without any adverse effect on the left control tibiae. The findings indicate that the administration of local low-dose alendronate could be an effective pharmacological means of improving bone formation in distraction osteogenesis.

High insulin enhances neutrophil transendothelial migration through increasing surface expression of platelet endothelial cell adhesion molecule-1 via activation of mitogen activated protein kinase.

AIMS/HYPOTHESIS: There is increasing evidence that hyperinsulinaemia is linked with the development of atherosclerosis in patients with diabetes. However, the mechanisms by which hyperinsulinaemia causes accelerated atherosclerosis, especially with respect to leukocytes transendothelial migration, are poorly understood. We examined whether hyperinsulinaemia directly affects neutrophil transendothelial migration and surface expression of related endothelial adhesion molecules. METHODS: Experiments on the transmigration of neutrophils from healthy volunteers and from patients with Type II (non-insulin-dependent) diabetes mellitus across human umbilical vein endothelial cells cultured in insulin-rich medium using cell-culture inserts were carried out. Migrated neutrophils were quantified by measuring their myeloperoxidase activities, and the surface expression of endothelial adhesion molecules was examined using an enzyme immunoassay. RESULTS: High insulin (over 50 microU/ml for 24 h) enhanced neutrophil transendothelial migration in a dose-dependent manner. This was associated with increased expression of platelet endothelial cell adhesion molecule-1 (PECAM-1) but not of intercellular adhesion molecule-1 (ICAM-1), P-selectin or E-selectin. Both phenomena were attenuated by pretreatment with a tyrosine kinase inhibitor, especially a mitogen-activated protein kinase inhibitor, but not by inhibitors of other second messengers. In addition, a mitogen-activated protein kinase activator, anisomycin, by itself enhanced both neutrophil transendothelial migration and PECAM-1 expression within 3 h in a dose-dependent manner. Pretreatment with nitric oxide synthase inhibitors had no effect on these events. CONCLUSION/INTERPRETATION: These results suggest that hyperinsulinaemia could accelerate atherosclerosis by directly enhancing neutrophil transendothelial migration through increasing endothelial PECAM-1 expression via mitogen-activated protein kinase activation.

High insulin exacerbates neutrophil-endothelial cell adhesion through endothelial surface expression of intercellular adhesion molecule-1 via activation of protein kinase C and mitogen-activated protein kinase.

AIMS/HYPOTHESIS: The association of insulin resistance and compensatory hyperinsulinaemia with increased coronary events in diabetic patients is poorly understood. There are few publications about the direct atherogenic actions of insulin on the endothelium compared with those on vascular smooth muscle cells. The aim of this study was to elucidate whether high insulin directly affects neutrophil-endothelial cell adhesion and surface expression of endothelial adhesion molecules. We also examined what intracellular mechanisms are involved in these events. METHODS: Studies of adhesion between neutrophils from healthy volunteers and human umbilical vein endothelial cells incubated in insulin-rich medium were carried out. Adhered neutrophils were quantified by measuring their myeloperoxidase activities and surface expression of endothelial adhesion molecules was examined using an enzyme immunoassay. RESULTS: High insulin enhanced neutrophil-endothelial cell adhesion with an increase in the expression of intercellular adhesion molecule-1 but not E-selectin or P-selectin. Both phenomena were attenuated by pretreatment with protein kinase C inhibitors and a mitogen activated protein kinase inhibitor. CONCLUSIONS/INTERPRETATION: These results suggest that hyperinsulinaemia causes vascular injury by directly exacerbating neutrophil-endothelial cell adhesion through increasing endothelial expression of intercellular adhesion molecule-1 via activation of protein kinase and mitogen activated protein kinase pathways.

Maternal transmission of Helicobacter pylori in the perinatal period.

OBJECTIVES: Studies indicate that Helicobacterpylori (HP) infection is closely related to gastric mucosa lesions and well-differentiated gastric cancer. In Japan, the HP-positive rate in childhood is 5-6%, which is similar to other developed countries, and in regard to the infection route, oral infection is considered important. To our knowledge there have been no reports on mother-to-child transmission and in this study we investigated maternal HP infection status to determine the potential of mother-to-child transmission in the perinatal period. METHODS: After obtaining informed consent from 1,588 pregnant women, mother's blood and cord blood were collected at delivery to measure HP antibody (Helico-G). Gastric contents from the neonates were cultured to isolate H. pylori (Skirrow medium). Vaginal discharge (73 women) and dental plaque scraping swabs (48 women) were collected before delivery, and milk (66 women) was collected after delivery from 212 HP antibody-positive pregnant women to detect H. pylori by PCR. RESULTS: The HP antibody-positive rate for the pregnant women was 29.2%. H. pylori was not detected in the vaginal discharge from HP antibody-positive pregnant women, but dental plaque scraping swabs from 4 women and milk from 4 women was positive. CONCLUSION: We considered that vertical infection during pregnancy or at delivery is unlikely as a route of mother-to-child HP antibody infection. However, horizontal infection through breast-feeding may occur.

Granulocyte colony-stimulating factor-producing small-cell carcinoma of the uterine cervix: report of a case.

A case of granulocyte colony-stimulating factor (G-CSF)-producing small-cell carcinoma of the uterine cervix is described. In a 70-yr-old woman, clusters of small cells with hyperchromatic nuclei at a high nuclear/cytoplasmic ratio were detected cytologically in the cervix. These clusters were diagnosed as a small-cell neuroendocrine carcinoma by the concomitant use of Grimelius staining and immunohistochemical staining, in addition to electron microscopic observation. This patient showed a significant increase in peripheral leukocytes, despite the absence of infectious signs. Immunohistochemical findings, together with a high blood G-CSF level, suggested the production of G-CSF from the tumor. Consistent with the knowledge that both small-cell carcinoma and G-CSF-producing tumors have a poor prognoses, the patient had no or partial response to therapies performed, and died from the cancer 11 mo after it was diagnosed. This case strongly indicates the need for early diagnosis of this type of tumor, based on cytological features.

Development and clinical application of a telemedicine support system in the field of perinatal patient management.

In recent years, perinatal patient management has been greatly improved due to the advance of medical technologies in various fields. The primary objectives of perinatal patient management are to discover signs and symptoms of fetal asphyxia and threatened premature delivery at an early stage and to initiate treatment as soon as possible. For this purpose, continuous monitoring of the fetal heart rate and uterine contractions is most effective. We developed a telemedicine support system for pregnant women and evaluated it to see if that makes it possible 1) to manage pregnant women monitored at home in the same way as those who visit hospitals on an ambulatory basis, and 2) to prevent adverse events in women in a high-risk pregnancy. The findings obtained in the present study showed that this system is useful for both purposes. Perinatal telemedicine is expected to progress significantly in the next few years, although there are a number of issues that need to be resolved in this area.