Prospects for optical clocks with a blue-detuned lattice.

We investigated the properties of optical lattice clocks operated with a repulsive light-shift potential. The magic wavelength, where light-shift perturbation for the clock transition cancels, was experimentally determined to be 389.889(9) nm for 87Sr. The hyperpolarizability effects on the clock transition were investigated theoretically. With minimal trapping field perturbation provided by the blue-detuned lattice, the fractional uncertainty due to the hyperpolarizability effects was found to be 2x10;{-19} in the relevant clock transition.

Measuring the frequency of a Sr optical lattice clock using a 120 km coherent optical transfer.

We demonstrate a precision frequency measurement using a phase-stabilized 120 km optical fiber link over a physical distance of 50 km. The transition frequency of the (87)Sr optical lattice clock at the University of Tokyo is measured to be 429228004229874.1(2.4) Hz referenced to international atomic time. The results demonstrate the excellent functions of the intercity optical fiber link and the great potential of optical lattice clocks for use in the redefinition of the second.

New limits on coupling of fundamental constants to gravity using 87Sr optical lattice clocks.

The 1S0-3P0 clock transition frequency nuSr in neutral 87Sr has been measured relative to the Cs standard by three independent laboratories in Boulder, Paris, and Tokyo over the last three years. The agreement on the 1 x 10(-15) level makes nuSr the best agreed-upon optical atomic frequency. We combine periodic variations in the 87Sr clock frequency with 199Hg+ and H-maser data to test local position invariance by obtaining the strongest limits to date on gravitational-coupling coefficients for the fine-structure constant alpha, electron-proton mass ratio mu, and light quark mass. Furthermore, after 199Hg+, 171Yb+, and H, we add 87Sr as the fourth optical atomic clock species to enhance constraints on yearly drifts of alpha and mu.

Trapping of neutral mercury atoms and prospects for optical lattice clocks.

We report vapor-cell magneto-optical trapping of Hg isotopes on the (1)S(0)-(3)P(1) intercombination transition. Six abundant isotopes, including four bosons and two fermions, were trapped. Hg is the heaviest nonradioactive atom trapped so far, which enables sensitive atomic searches for "new physics" beyond the standard model. We propose an accurate optical lattice clock based on Hg and evaluate its systematic accuracy to be better than 10;{-18}. Highly accurate and stable Hg-based clocks will provide a new avenue for the research of optical lattice clocks and the time variation of the fine-structure constant.

Young C3H mice infected with Toxoplasma gondii are a novel experimental model of communicating hydrocephalus.

The effects of leptomeningeal inflammation on the development of hydrocephalus are less understood than those of obstructing the flow of cerebrospinal fluid (CSF) in animal models. We succeeded in introducing a novel experimental model of hydrocephalus and analysed changes in histopathology and CSF flow in mice infected with an avirulent Fukaya strain of Toxoplasma gondii (T. gondii). Six to 7 week-old male mice were orally inoculated with a brain homogenate containing ten T. gondii cysts. The cerebral ventricles became enlarged in all C3H/HeN and C57BL/6 mice 4 weeks after T. gondii infection, but mildly in BALB/c mice. In addition to the lateral ventricle, the third and fourth ventricles and Sylvian aqueducts were dilated in all mice. Lymphocytes and monocytes infiltrated the subarachnoid space. Indian ink particles required more time to pass from the lateral ventricle to the cervical lymph nodes, although they reached the subarachnoid space. Computed tomography ventriculography demonstrated that the CSF was not obstructed during passage through the ventricular systems, but contrast remained static in the lateral ventricle only in infected mice. These results indicated that the infected mice developed communicating type hydrocephalus without obstructive or mass lesions in the ventricles. The hydrocephalus that arises in mice infected with T. gondii is considered a consequence of leptomeningeal inflammation that blocks CSF circulation at the subarachnoid space, implying that leptomeningeal inflammation is important in other types of hydrocephalus.

Secretory IgA, salivary peroxidase, and catalase-mediated microbicidal activity during hydrogen peroxide catabolism in viridans streptococci: pathogen coaggregation.

Viridans streptococci can kill methicillin-resistant Staphylococcus aureus (MRSA) through the production of hydrogen peroxide (H2O2). However, several hundred viridans streptococci cells are necessary to kill 1 cfu of MRSA. We analyzed the potency of bactericidal and fungicidal effector molecules induced by catabolism of H2O2 in the oral cavity. Secretory IgA (SIgA) and an unidentified salivary component bound Streptococcus sanguinis, a viridans streprococcus, and MRSA into coaggregates. In these coaggregates, salivary peroxidase and the MRSA catalase produced singlet molecular oxygen (1O2) from H2O2 produced by viridans streptococci. SIgA converted 1O2 into ozone, which has potent bactericidal and fungicidal activity. We calculated that <10 cfu of Streptococcus sanguinis were necessary to kill 1 cfu of MRSA in the coaggregate. SIgA, Aspergillus niger catalase, and H2O2 in saliva killed Candida albicans, which is highly resistant to reagent H2O2. Together with indigenous bacteria and innate immunity, SIgA potentially constitutes a novel system that may sustain oral homeostasis.

Hedgehog signaling enhances core-binding factor a1 and receptor activator of nuclear factor-kappaB ligand (RANKL) gene expression in chondrocytes.

Hedgehog signaling is considered to play a crucial role in chondrogenesis by regulation through a network of cytokine actions, which is not fully understood. We examined the effect of hedgehog signaling on the expression of core-binding factor a1 (Cbfa1), a critical transcription factor for the development of bone and cartilage. Primary chondrocytes prepared from the costal cartilage of newborn mice were treated with N-terminal fragment of recombinant murine sonic hedgehog (rmShh-N). Northern blot analysis indicated that Cbfa1 mRNA expression levels in the chondrocyte cultures were elevated by the treatment with rmShh-N. rmShh-N treatment enhanced 1.8 kb Cbfa1 promoter activity in chondrocytes, suggesting the presence of transcriptional control. As Cbfa1-binding site(s) have been located in the promoter of the receptor activator of nuclear factor-kappaB (RANK) ligand (RANKL) gene, we also examined RANKL expression. rmShh-N treatment upregulated RANKL and RANK mRNA expression levels in chondrocytes. Interestingly, RANKL suppressed the hedgehog enhancement of alkaline phosphatase activity in chondrocytes, suggesting the presence of a link between these signaling molecules. We conclude that hedgehog signaling activates Cbfa1 gene expression through its promoter in chondrocytes, and also activates and interacts with RANKL to maintain cartilage development.

The measurement of parasite antigen-specific IgE levels using anti-IgE monoclonal antibodies and biotinylated antigens.

We studied and evaluated an ELISA system, using a sandwich method with a monoclonal antibody against the Fc domain of IgE molecules and biotinylated antigens, to detect parasite antigen-specific IgE quantitatively. The specific IgE ELISA titre increases linearly in a dose-dependent manner when the concentration of total IgE in samples is less than 2,000 ng/ml. Sera from IgE-deficient SJA/9 mice infected with Trichinella spiralis failed to give any measurable IgE, suggesting that other classes of immunoglobulins have no effect on this assay. The titre showed a good correlation with PCA titre. A high concentration of the serum from Toxocara canis-infected mice reduced the T. spiralis-specific IgE ELISA titre, suggesting that the ELISA system is influenced by a huge amount of IgE against epitopes different from those of target antigens. This ELISA system can also be applied for detecting other classes or subclasses of antigen-specific immunoglobulins.

Cloning and characterization of a novel gene encoding keratin-like protein from nematode Nippostrongylus brasiliensis.

Nippostrongylus brasiliensis (Nb) is one of the most important parasites in studying Th2 immune response of the host, but little is known about its antigenic structures of the excretory-secretory or structural proteins of the parasite. Here we report cloning and characterization of a novel antigenic gene from cDNA library of Nb adult worm by immunoscreening. The positive clone, KLP-Nb, had an open reading frame of 612 bp that encodes a 203-amino-acid protein and was homologous to 'similar to keratins in a glycine-rich region' of Caenorhabditis elegans. Its expression was confirmed by Northern blotting and IgG enzyme-linked immunosorbent assay. This protein seems to be one of the components of cuticle that covers the nematode body.

Diagnosis of Toxoplasma meningoencephalitis in a non-AIDS patient using PCR.

We report herein a rare case of Toxoplasma gondii meningoencephalitis in a non-AIDS patient. Although T. gondii itself was not detected in nucleated cells in peripheral blood and cerebrospinal fluid under the microscope, the polymerase chain reaction method effectively detected the B1 gene of T. gondii in the cells. A serological examination showed increased levels of the IgG but not the IgM antibody to T. gondii, suggesting reactivation of the infection in the brain.

[Pulmonary Mycobacterium Kansasii infection in the southern area of Fukuoka prefecture].

Cases of pulmonary infection caused by Mycobacterium kansasii (Mk) in our hospital located at the mid-northern area of the Kyushu district, which is in the southern part of Fukuoka prefecture were evaluated. Mk infection is not so rare in other areas of Japan, such as Tokyo and Kinki district, however, there has been no published report on the disease from the Kyusyu district. Therefore, the frequency and the clinical features of our cases of Mk infection were analyzed. During 17 years from 1982 to 1998, there were 14 patients of Mk infection out of 241 nontuberculous mycobacteriosis (NTM). There were 595 patients of culture-positive pulmonary tuberculosis without prior treatment (Tbc). The proportion of Mk/Tbc was 2.4% and that of Mk/NTM was 5.8%. During the period A (from 1982 to 1994) the ratio of Mk/Tbc was 5/462 (1.1%), while on the other side that of Mk/Tbc during the period B (from 1995 to 1998), it was 9/133 (6.8%), which was significantly (P < 0.01) higher compared with that in the period A. Although the patients of Mk infection in our hospital had been rare until 1994, from the results mentioned above, it was considered that the frequency of Mk infection in our hospital has increased to some extent since 1995. One of the characteristics in our cases was that the ratio of female (42.9%) was relatively high. All the female patients were considered to be compromised hosts. The results of the drug resistance tests were consistent with the other reports in our country. By the combination treatment including rifampicin as the major drug, the negative conversion of culture were obtained within 2 months in all our cases.

Mechanism of hypergammaglobulinemia by HIV infection: circulating memory B-cell reduction with plasmacytosis.

The mechanism of hypergammaglobulinemia in patients infected with HIV has remained unclear in spite of the identification of a reduction of CD4+ T cells. The amounts of CD27+ memory B cells were remarkably reduced in the peripheral blood and immunoglobulin (Ig) production was diminished in HIV-infected patients. Some of the freshly isolated patients' T cells expressed the CD70 (CD27 ligand) on the surface and the CD70 expression on both of the CD4+ and CD8+ T cells was greatly enhanced by various stimuli. It was also striking that plasmacytosis was observed in patients' bone marrow. Thus, our findings suggest that CD70 expressed spontaneously or by activation on T cells of HIV-infected patients stimulates memory B cells via CD27 and promotes their differentiation into plasma cells, resulting in the elevation of serum Ig levels and the elimination of circulating memory B cells in HIV-infected patients.

[Follicular bronchiolitis associated with pulmonary tuberculosis--report of a case].

The patient, a 39-year-old man, presented in May 1997 with an untreated persistent cough with excessive sputum of 5 years' duration. He was admitted to hospital because of the severity of the symptoms and the presence of acid-fast bacilli in his sputum. These bacilli were identified as Mycobacterium tuberculosis by the polymerase chain reaction method. After treatment with antituberculous drugs was initiated, his symptoms and the patchy infiltrative shadows on his chest radiographs gradually resolved. However, the patient continued to expectorate a purulent sputum, showed diffuse micronodular shadows on chest radiographs, and had hypoxemia as well as mixed ventilatory and small airway disturbances on pulmonary function tests. We performed a video-assisted thoracoscopic biopsy of the lung, which revealed follicular bronchiolitis.

[Clinical study on the cases in which INH or RFP was discontinued during treatment for pulmonary tuberculosis].

Short course regimens; 2HRZ (E)(S)/4HR (E), 6HRS (E)/3-6HR and 6-9HR have been accepted as a standard chemotherapy (SC) for initial treatment of pulmonary tuberculosis in Japan. We studied the frequency of the treatment completion, the causes of the treatment failure and the outcome of the patients in whom INH or RFP was discontinued within 6 months after starting SC. The subjects included 597 newly diagnosed culture positive pulmonary tuberculosis patients admitted to 16 national hospital in 1996. Results were as follows. 1. In 47 (7.9%) of the 597 patients, either INH (19; 3.2%) or RFP (33; 5.5%) was discontinued. These 47 cases were defined as a SC incompleted group and the other 550 as a SC completed group. 2. The patients in the SC incompleted group were seen more frequently in the ages of 20s (11.9%), 50s (10.9%), 60s (11.7%) or 70s (11.4%). 21 (13.6%) of 154 female patients and 26 (5.9%) of 443 male patients were in the SC incompleted group. 3. The causes of cessation of INH or RFP were drug side effects (33; 5.5%), drug resistance (10; 1.7%) and complications or underlying diseases (8; 1.3%). 4. Fever or eruption (19; 3.2%) and drug induced hepatitis (12; 2.0%) were frequently seen as drug related side effects causing the cessation of INH or RFP. 5. The rate of culture negative conversion of TB bacilli at 6 months after the start of the treatment was 98.9% in the SC completed and 88.9% in the SC incompleted group respectively. In the SC incompleted group, there were three cases continuously positive and two other patients who relapsed and became culture positive again. In these five patients, INH or RFP was discontinued because of drug resistance.

[Bone metabolism and angiogenesis].

Bone metabolism is regulated not only by the nutrition supplied by vessel but also by the signals from the cells in vascular tissues. Identification of such signaling molecules has been the major issue in the field of research on the relationship between bone and vasculatures. This review touches on the recent findings on the expression and functions of such signaling molecules including VEGF, MMP and non-collagenous bone matrix proteins.

[The meaning of phosphate in bone formation].

Bone formation requires phosphate to calcify the osteoid produced by osteoblasts, Pit-1, a natrium-phosphate cotransporter, is expressed in osteoblasts and its expression levels are regulated developmentally and also by hormones and cytokines. Another type of phosphate transporter is expressed in osteoclasts and its function is required for bone resumption. These observations suggest that phosphate transport into the bone cells may play a role in regulation of bone formation and resorption in vivo and in the pathological situation in patients with bone diseases.

[Comparison of chest CT findings between suspected and definite cases of primary pulmonary M. avium complex infection].

It is very difficult to treat pulmonary infection with MAC, because we have few effective drugs against this organism. In this situation, an early diagnosis and treatment are very important to manage this disease. We evaluated chest CT scans of the primary pulmonary MAC infection which had no underlying lung diseases and no immunocompromised diseases such as HIV infection. We defined suspected cases of pulmonary MAC infection as cases in which abnormal features of chest CT scans were recognized but frequency of detection of organisms of MAC did not fulfil the diagnostic criteria for atypical mycobacteriosis according to Japanese Mycobacteriosis Research Group of the National Chest Hospitals. CT scans of suspected cases were compared with the definite cases. Results obtained were as follows: 1. In classification by CT scans of primary pulmonary MAC infection, the proportion of localized type and diffuse type was the same both in suspected and definite cases. In localized type, more tuberculosis-like pattern was seen in definite cases. 2. In suspected cases, characteristic features of CT scans of primary pulmonary MAC infection were recognized in the same frequency as in definite cases. 3. In pulmonary tuberculosis-like type, definite cases showed more cavitary lesions than suspected cases. These results showed that a careful long term follow-up of suspected cases with frequent bacteriological tests of sputum and chest CT scannings was important for early diagnosis of primary pulmonary MAC infection.

A pivotal role of cell-bound but not soluble CD4 molecules in full development of lupus-like manifestations in MRL-Fas(lprcg)/Fas(lprcg) mice.

The role of CD4 molecules in the autoimmune and lymphoproliferative syndrome caused by murine Fas mutations was studied using the novel systemic lupus erythematosus (SLE) model, MRL-Fas(lpr(cg))/Fas(lprcg) (MRL-lpr(cg)) mice, in combination with the novel mutant CD4 gene producing soluble CD4 (sCD4) instead of membrane-bound CD4 (mCD4). For this purpose, various autoimmune manifestations were compared among MRL-lpr(cg) mice homozygous (CD4slprcg), heterozygous (CD4s/mlpr(cg)), and wild-type (CD4mlpr(cg)) for the CD4 mutation. The mortality, glomerulonephritis, proteinuria, and lymphadenopathy were significantly ameliorated in CD4slprcg compared with CD4mlpr(cg) and CD4s/mlpr(cg) mice, both being comparable in these clinical characteristics. In parallel with the clinical improvement, the serum levels of immunoglobulin, anti-DNA antibodies, anti-nuclear antibodies and immune complexes, and the extent of glomerular immune deposition, were significantly lower in the former. The results indicate that mCD4 is important and can not be replaced by sCD4 in full development of SLE-like manifestations, and suggest that CD4+ T cells may aggravate the autoimmune disease by stimulating autoreactive B cells to produce autoantibodies through their helper activity in Fas mutant models. The sCD4 levels in the serum and spleen elevated with the increased accumulation of B220+CD4-CD8- (double-negative (DN)) T cells in CD4slpr(cg) mice. This, together with the significantly milder lymphadenopathy associated with lower DN T cell contents in CD4slpr(cg) than CD4mlpr(cg) mice, implies that some of abnormal DN T cells may be derived from cells of the CD4 lineage.

[Evaluation of CT appearance of Mycobacterium avium complex infection--comparison with bronchiectasia].

We compared computed tomographic pictures (CT) of primary pulmonary mycobacterium avium complex (MAC) infection with bronchiectasia (BE). These patients were examined during the period from 1988 to 1996. There were 51 patients of pulmonary MAC infection group (13 males and 38 females) with a mean age of 67.5 years and 27 patients of BE group (8 males and 19 females) with a mean age of 53.9 years. The results were as follows: 1. In both groups, bronchiectasis was most commonly found in the middle lobe and in the lingula. In pulmonary MAC infection group, 38 patients (74.5%) had bronchiectasis in the middle lobe, and 40 patients (78.4%) had them in the lingula. In BE group, 18 patients (66.7%) had them in the middle lobe and in the lingula respectively. In the lower lobe, bronchiectasis of BE group was observed more frequently. And in pulmonary MAC infection group, 15 patients (29.4%) had bronchiectasis in the central zone, 42 patients (82.4%) had them in the intermediate zone, and all 51 patients had them in the peripheral zone. On the other hand, in BE group, 18 patients (66.7%), 27 patients (100%) and 21 patients (77.8%) had them in the central zone, in the intermediate zone and in the peripheral zone respectively. Bronchiectasis of pulmonary MAC infection was observed in peripheral zone more frequently than that of BE group. 2. By the type of bronchiectasis, saccular bronchiectasis was observed more frequently in BE group than in pulmonary MAC infection group. 3. Nodules were seen in pulmonary MAC infection group significantly more than in BE group. They were seen in 96% of lobes with bronchiectasis, and 50% of lobes without bronchiectasis in pulmonary MAC infection group. It was thought that the bronchiectasis with nodules predominantly in the peripheral zone was a characteristic CT finding of primary pulmonary MAC infection. As this finding was different from that of BE, it is suggested that primary pulmonary MAC infection caused this type of bronchiectasis.

Inhibition of interleukin 5 production with no influence on interleukin 4 production by an anti-allergic drug, tranilast, in Toxocara canis-infected mice.

Tranilast is well-known as a useful drug for allergic diseases. This drug is believed to exhibit its therapeutic effects by inhibiting the release of chemical mediators from mast cells and basophils. Effects of tranilast on T helper type 2 (Th2) cytokine production were investigated in mice infected with Toxocara canis (Tc). Tranilast reduced interleukin (IL)-5 production in a dose-dependent manner but not IL-4 production at all in lung and spleen cells from Tc-infected mice cultured under stimulation with excretory-secretory antigen. Obvious IL-5 mRNA expression was observed at week 1 in the lung alone, and IL-4 mRNA expression was detected at similar levels at weeks 1-6 of infection in both lung and spleen. IL-5 but not IL-4 mRNA expression in the lung was significantly inhibited by daily administration of 100 mg/kg of tranilast for 1 week. This treatment also reduced the serum IL-5 level. Thus, tranilast inhibited IL-5 but not IL-4 production either in vitro or in vivo. The results imply that IL-5 and IL-4 production by Th2 cells may be controlled through different mechanisms.