Rodlike particles in gas discharge plasmas: theoretical model

Recently, complex plasmas with strongly asymmetric (rodlike) particles were investigated experimentally in rf and dc discharges [V. I. Molotkov et al., JETP Lett. 71, 102 (2000); B. M. Annaratone et al., Phys. Rev. E 63, 036406 (2001)]. In this paper, a theoretical model is proposed which describes the behavior of such systems. Major results of the proposed model are the following: Equilibrium charge is calculated for particles orientated perpendicular and parallel to the ion flux (electric field); equilibrium states of particles (orientation angle and levitation height) are obtained; energy of electrostatic interaction between rods is derived, depending on the mutual orientation. Comparison of experimental and theoretical results shows quite good agreement. In conclusion, some important theoretical issues as well as possible new experiments are discussed.

11B NMR study of p-carboxybenzeneboronic acid ions for complex formation with some monosaccharides

The 11B NMR spectra of p-carboxybenzeneboronic acid (PCBA) ions demonstrated that their chemical shifts depend on the pH. At a lower pH, PCBA exists as a mixture of neutral PCBA and the monoanion with a trigonal structure, and at higher pH as the dianion with a tetrahedral structure. In the intermediate pH region, both the mono- and dianion coexist. The pKa of the monoanion of PCBA has been estimated to be 8.53. The complex formation constants of PCBA with several monosaccharides suggest that PCBA-fructose complex is most predominant.

Distinct regulatory mechanism for p70 S6 kinase beta from that for p70 S6 kinase alpha

BACKGROUND

A novel ribosomal S6 kinase, termed p70 S6 kinase beta (p70beta), has a highly homologous amino acid sequence to that of p70/p85 S6 kinase (p70alpha). This includes the critical phosphorylation sites, Thr252, Ser394 and Thr412 in p70alpha1, which correspond to Thr241, Ser383 and Thr401 in p70beta1, respectively. However, the regulatory mechanism for p70beta remains to be elucidated.

RESULTS

We report here the expression and the mechanism of in vivo regulation of p70beta. Two isoforms, p70beta1 and p70beta2, were expressed in a variety of tissues at a different level. p70beta1 was mainly targeted to the nucleus, whereas p70beta2 dispersed throughout the cytoplasm including nucleoplasm. The kinase activity of p70beta1 was less sensitive to the inhibition induced by rapamycin, wortmannin and amino acid withdrawal than that of p70alpha. The portion of p70beta activity inhibited by rapamycin was rescued by the rapamycin-resistant mutant of the mammalian target of rapamycin (mTOR). Mutational analysis revealed that the phosphorylation of Thr241 and Thr401 in p70beta1 was indispensable for the kinase activity. In contrast, a p70beta1 mutant in which Ser383 was substituted with Gly (S383G) still retained nearly the half maximal activity. Sequential phosphorylation of wild-type and S383G mutant of p70beta1 with mTOR and 3-phosphoinositide-dependent protein kinase 1 (PDK1) in vitro synergistically activated their kinase activities.

CONCLUSION

These results indicate that p70beta is regulated by the mTOR- and PDK1-signalling pathways through a synergistic interaction between phosphorylated Thr241 and Thr401, while Ser383 plays minor role in their activation mechanism. Activated p70beta may be less sensitive to dephosphorylation mediated by putative phosphatases activated by rapamycin, amino acid withdrawal, and probably wortmannin.

Association between serum leptin concentrations and bone mineral density, and biochemical markers of bone turnover in adult men

Leptin, the product of the ob gene, has been shown to inhibit bone formation in mice. We addressed whether leptin has any role in the regulation of bone mineral density (BMD) in humans. Subjects were 221 adult men with a mean (+/-SD) age and body mass index of 52.1 +/- 8.7 yr and 23.6 +/- 2.8 kg/m2. Serum leptin, carboxyterminal propeptide of type 1 procollagen (PICP; a marker of bone formation), and cross-linked carboxyterminal teleopeptide of type 1 collagen (a marker of bone resorption) were measured by RIA. BMD was assessed by single photon absorptiometry, and total fat mass was determined by bioimpedance analysis. BMD was inversely associated with serum leptin concentrations and total fat mass after adjustment for body weight. PICP, but not cross-linked carboxyterminal teleopeptide of type 1 collagen, was inversely correlated with serum leptin. These results may suggest that an increase in serum leptin reduces bone formation and decreases BMD in adult men. Leptin may be a regulator of BMD in humans.

Control of arterial partial pressure of oxygen in patients with respiratory abnormalities using an adaptive observer

A system for controlling the arterial partial pressure of oxygen in patients on long-term oxygen therapy is proposed. After performing a parameter estimation of the model of pulmonary system, an adaptive observer is applied to perform the control task. The observer considers the model uncertainties as disturbances and rejects their impact on the system. As a result of this, the quality of the control can be drastically improved. The presented simulation and experimental results show the effectiveness of the proposed scheme. The proposed control scheme is applicable without preliminary adjustment of the control parameters.

Separate measurements of the flexoelectric and surface polarization in a model nematic liquid crystal p-methoxybenzylidene-p'-butylaniline: validity of the quadrupolar approach

The temperature dependences of the surface polarization have been measured at the interface of a conductive glass with both the homogeneously and homeotropically oriented nematic liquid crystal p-methoxybenzylidene-p(')-butylaniline. The polarization was found in the field-off regime from the pyroelectric response of a cell to a short laser pulse, absorbed in the bulk of the liquid crystal. The temperature increment was calculated from the measurements of the birefringence induced by the same light pulse. It has been shown that the surface polarization at the homeotropic (m(h)) and planar (m(p)) interfaces is directed from an interface into the bulk and from the bulk to an interface, respectively (with a magnitude m(h) approximately -0.3 pC/m and m(p) approximately +0.2 pC/m at 25 degrees C). The experimental data may be explained in terms of the quadrupole model of the order-electric polarization with account of some additional contribution from molecular dipoles. The same technique also allows for the measurements of the z component of the flexoelectric polarization using a pyroelectric response of a hybrid (homeoplanar) aligned nematic cell and proper subtracting of the surface contributions. The flexoelectric polarization has been shown to be opposite to the sum of the surface terms m(h)+m(p) and directed from the planar to homeotropic interface. This means that the sum of the flexoelectric coefficients e=(e(1)+e(3)) is positive (e congruent with 1.7 pC/m at 28 degrees C). The temperature dependence of e has been shown to involve a combination of both the quadrupolar and dipolar contributions.

Severe hypospadias repair with meatal based paracoronal skin flap: the modified Koyanagi repair

PURPOSE

Various techniques have been reported to repair severe hypospadias. The Koyanagi repair uses a meatal based foreskin flap. We modified this procedure and reviewed the outcome of the repair of severe hypospadias.

MATERIALS AND METHODS

The modified Koyanagi repair was performed in 151 children 7 months to 15 years old (mean age 3 years) with severe hypospadias. The records of these patients were reviewed. In all cases the meatus was at or proximal to the penoscrotal junction. Followup was 6 months to 16 years (mean 6 years). Flap design is the same as in the Koyanagi repair, although our modified technique requires removal of the subcutaneous tissue of the distal portion of the flap, which acts as a full-thickness free skin graft.

RESULTS

A fistula developed in 19 patients (12.6%), meatal stenosis in 3 (2%) required meatoplasty and infection in 2 (1.3%) resulted in a regressed meatal position. Good cosmetic results were achieved in all except the latter 2 cases.

CONCLUSIONS

Our modified Koyanagi repair affords an excellent cosmetic appearance. The complication rate is relatively low and compares favorably with that of other techniques.

[Reconstruction of the cervical esophagus using cutaneous or musculocutaneous flaps]

Reconstruction of the cervical esophagus using cutaneous or musculocutaneous flaps is described. The delto-pectoral cutaneous flap, latissimus dorsi or pectoris major musculocutaneous flap, free forearm cutaneous flap, and free rectus abdominis musculocutaneous flap are generally used for reconstruction of the cervical esophagus. Although free jejunal transfer with microsurgery is now common for reconstruction of the cervical esophagus, cutaneous or musculocutaneous flaps remain useful in high-risk patients or patients in whom free jejunal transfer or gastrointestinal reconstruction would prove incompetency due to a history of abdominal surgery or other reasons. Cutaneous or musculocutaneous flaps are also used in patients with failure of free jejunal transfer or incurable fistula after reconstruction using the stomach or colon for thoracic esophageal cancer.

Impaired FHIT expression characterizes serous ovarian carcinoma

The FHIT (fragile histidine triad) gene on chromosome 3p14.2 is a candidate tumour suppressor gene. To define the role of the FHIT gene in the development of ovarian cancer, we have examined 33 ovarian carcinomas, 2 borderline tumours and 10 benign adenomas for the presence of FHIT gene alterations. FHIT transcripts were analysed by RT-PCR and sequencing. Aberrant FHIT transcripts were observed in 5/33 carcinomas (15%) and in 1 of 2 borderline tumours. Loss of normal FHIT transcript was observed in 5/33 carcinomas (15%) but not in 2 borderline tumours or 10 benign adenomas. Allelic losses at D3S1300 and D3S4103, both located within intron 5 of FHIT, were detected in 5/24 (21%) and 5/25 (20%) informative ovarian carcinomas, respectively. Expression of Fhit protein was analysed by immunohistochemistry in 44 carcinomas, 19 borderline tumours and 16 benign adenomas. Loss or significantly reduced expression of Fhit protein was observed in 6/44 (14%) ovarian carcinomas but not in any of 19 borderline tumours or 16 benign adenomas. The impaired Fhit protein expression was significantly correlated with the loss of normal FHIT transcription. Most notably, loss of normal FHIT transcript and impaired expression of Fhit protein occurred only in serous adenocarcinomas of grade 2 and 3 (5/15; 33% and 6/19; 32%, respectively). The present data suggest that inactivation of the FHIT gene by loss of expression is one of the important molecular events associated with the genesis of ovarian carcinoma, especially of high-grade serous carcinoma.

Body fatness and fat distribution as predictors of metabolic abnormalities and early carotid atherosclerosis

OBJECTIVE

To test the hypothesis that intra-abdominal fat plays a primary role over general adiposity for metabolic abnormalities and atherosclerosis.

RESEARCH DESIGN AND METHODS

We cross-sectionally studied 849 Japanese men aged 50.3 +/- 8.5 years (range 20-78) with BMI 23.5 +/- 2.9 kg/m(2). Intimal-medial thickness (IMT) of the carotid artery was measured by ultrasound. General adiposity was assessed by BMI. Waist circumference and waist-to-hip ratio (WHR) were used as a surrogate measure for abdominal fat. Abdominal subcutaneous fat area (ASF) and intra-abdominal fat area (IAF) were measured by computed tomography. Correlations between these measures and carotid IMT were analyzed. The interaction of generalized adiposity (BMI) and IAF in relation to metabolic variables, such as glucose tolerance, insulin resistance, and serum lipids, was also evaluated.

RESULTS

BMI, waist circumference, WHR, ASF, and IAF were all correlated with carotid IMT. Adjustment for BMI eliminated the associations between IMT and waist circumference, ASF, and IAF. In contrast, WHR retained a significant correlation with IMT. BMI and IAF were associated with insulin resistance, glucose tolerance, HDL cholesterol, and blood pressure independently of each other. IAF was an independent correlate for serum triglyceride, but BMI was not.

CONCLUSIONS

The primary importance of IAF over general adiposity for carotid atherosclerosis was not confirmed. Caution is recommended when using WHR as a measure of abdominal fat. The roles of IAF for metabolic abnormalities may be more limited than conventionally thought. BMI and WHR are simple and better clinical predictors for carotid atherosclerosis versus IAF.

Similar subunit interactions contribute to assembly of clathrin adaptor complexes and COPI complex: analysis using yeast three-hybrid system

Clathrin adaptor protein (AP) complexes are heterotetramers composed of two large, one medium, and one small subunits. By exploiting the yeast three-hybrid system, we have found that an interaction between the two large subunits of the AP-1 complex, gamma-adaptin and beta1-adaptin, is markedly enhanced in the presence of the small subunit, sigma1. Similarly, two large subunits of the AP-4 complex, epsilon-adaptin and beta4-adaptin, are found to interact with each other only in the presence of the small subunit, sigma4. Furthermore, we have found that an interaction between two large subunits of the COPI F subcomplex, gamma-COP and beta-COP, is detectable only in the presence of zeta-COP. Because these COPI subunits have common ancestral origins to the corresponding AP subunits, these three-hybrid data, taken together with the previous two-hybrid data, suggest that the AP complexes and the COPI F subcomplex assemble by virtue of similar subunit interactions.

Cutting edge: IL-18-transgenic mice: in vivo evidence of a broad role for IL-18 in modulating immune function

IL-18 has been shown to be a strong cofactor for Th1 T cell development. However, we previously demonstrated that when IL-18 was combined with IL-2, there was a synergistic induction of a Th2 cytokine, IL-13, in both T and NK cells. More recently, we and other groups have reported that IL-18 can potentially induce IgE, IgG1, and Th2 cytokine production in murine experimental models. Here, we report on the generation of IL-18-transgenic (Tg) mice in which mature mouse IL-18 cDNA was expressed. CD8+CD44high T cells and macrophages were increased, but B cells were decreased in these mice while serum IgE, IgG1, IL-4, and IFN-gamma levels were significantly increased. Splenic T cells in IL-18 Tg mice produced higher levels of IFN-gamma, IL-4, IL-5, and IL-13 than control wild-type mice. Thus, aberrant expression of IL-18 in vivo results in the increased production of both Th1 and Th2 cytokines.

The rebuilding of normal venous circulation for transverse-sigmoid dural arteriovenous fistulas by percutaneous transluminal angioplasty. A case report

The etiology of dural arteriovenous fistulas (DAVFs) remains controversial as is the issue of whether occlusion or stenosis of the transverse sinus and sigmoid sinus is a cause or a result of DAVFs. We report a case of DAVFs with transverse-sigmoid sinus occlusion and cortical venous reflux. In this case, the reconstruction of normal venous circulation by percutaneous transluminal angioplasty (PTA) for the occluded sinus was performed and cortical venous reflux diminished. PTA may be a useful treatment for DAVFs with occluded or stenotic sinus.