Oxygen-vacancy-induced orbital reconstruction of Ti ions at the interface of LaAlO3/SrTiO3 heterostructures: a resonant soft-X-ray scattering study

Resonant soft-x-ray scattering measurements have been performed to investigate interface electronic structures of (LaAlO(3)/SrTiO(3)) superlattices. Resonant scattering intensities at superlattice reflections show clear evidence of degeneracy lifting in t(2g) states of interface Ti ions. Polarization dependence of intensities indicates the energy of d(xy) states is lower by ~1 eV than two other t(2g) states. The energy splitting is insensitive to epitaxial strain. The orbital reconstruction is induced by oxygen vacancies and confined to the interface within two unit cells, indicating charge compensation at the polar interfaces.

SU-E-T-175: A Study on Design and Fabrication of 25 * 25 cm2 Beam Monitor for Scanning Carbon Beam

PURPOSE

The KHIMA is developing a superconducting cyclotron of 430 MeV/u for carbon therapy. In order to verify the irradiated beam dose and position, detectors have been developed. The detector has a considered in the active area of 25*25cm² to cover the entire beam scanning area. To minimize the loss of data during beam irradiation, a fast data acquisition system was required.

METHODS

A PPIC type was adopted. To measure the beam position and profile, the electrode of PPIC was designed to have a strip pattern. The PCB technique was applied to large area with thin FR-4 plate of electrodes. The chamber has a strip interval of 1.7mm. He was used as the filling gas in order to reduce the ion collection time. Output signal from the detector connected to the two charge integrators was transferred every 10us. The signal can be stored temporarily in memory of FPGA through one of 2 integrators.

RESULTS

The fabricated large electrode plates did not show any deformation on their shape. Depending on the beam position, the amount of dose from the ion chamber will be measured. For fast data acquisition, the DAQ board was fabricated by using 2 charge integrators and the FPGA. The obtained data from the ion chamber was displaced on the PC screen every 10us. The fluence map of a single layer will be shown on the PC screen at the end of beam irradiation on the layer. The output data from the profile monitor will be compared with Gafchromic Film results.

CONCLUSIONS

PCB method for active area of thin electrodes was used in the strip pattern. To reduce the loss of data during irradiation, 2 charge integrators are used alternately. The response of the readout data was set 1 0us. The beam tests will be performed with the MC-50 Cyclotron.

Fragile magnetic ground state in half-doped LaSr2Mn2O7

We investigated the orbital and antiferromagnetic ordering behaviors of the half-doped bilayer manganite La(2-2x)Sr(1+2x)Mn2O7 (x ≃ 0.5) by using Mn L(2,3)-edge resonant soft x-ray scattering. Resonant soft x-ray scattering reveals the CE-type orbital order below T(oo) ≃ 220  K, which shows partial melting behavior below T(m) ≃ 165  K. We also found coexistence CE- and A-type antiferromagnetic orders. Both orders involve the CE-type orbital order with nearly the same orbital character and are coupled with each other. These results manifest that the ground state with the CE-type antiferromagnetic order is easily susceptible to destabilization into the A-type one even with a small fluctuation of the doping level, as suggested by the extremely narrow magnetic phase boundaries at x ≃ 0.5±0.005.

Hypofractionated radiotherapy for patients with locally advanced pancreatic cancer using tomotherapy Hi-Art and CyberKnife: A study of the treatment outcome and failure patterns

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Background: To evaluate the treatment outcome and pattern of failure in the patients with locally advanced pancreatic cancer, who were treated with hypofractionated radiotherapy (RT) using TomoTherapy Hi-Art and Cyberknife.

Methods: From April 2004 to May 2010, Twenty four patients with locally advanced pancreatic cancer received hypofractionated RT using TomoTherapy Hi-Art and Cyberknife at Seoul St. Mary's Hospital, the Catholic University of Korea. Eleven patients (45.8%) were treated using TomoTherapy Hi-Art and 13 patients (54.2%) using Cyberknife. The total dose delivered were 45∼55 Gy (median: 50 Gy) in 15∼22 fractions with TomoTherapy Hi-Art and 24∼40 Gy (median 30 Gy) in 3∼5 fractions with Cyberknife. The RECIST version 1.1 was used for the response evaluation. The follow-up duration was 3.0∼77.1 months (median: 34 months).

Results: In the initial response evaluation, the rates of partial response, stable disease and progressive disease were 45.8%, 54.2% and 0%, respectively. Median survival duration was 11.1 months. One year and two year survival rates were 39.4% and 21.1%, respectively. Two patients (8.3%) had local failures and 11 patients (45.8%) had distant failures. Distant failures were main cause of failures. Median time to distant failures was 7.8 months and one year distant progression-free survival rate was 35.1%. The difference of the treatment outcome between TomoTherapy Hi-Art and Cyberknife was not statistically significant. Most patients experienced abdominal discomfort and pain after RT. However, no severe gastrointestinal complication such as ulcer, bleeding, perforation and fistula were noted.

Conclusions: Hypofractionated RT for the patients with locally advanced pancreatic cancer showed excellent local control. However, overall survival still remains poor because of distant failures. Therefore, effective systemic chemotherapy should be considered with RT, either concurrently or sequentially.

No significant financial relationships to disclose.

Development of a stabilizer for lyophilization of an attenuated duck viral hepatitis vaccine

The live attenuated vaccine against duck viral hepatitis currently available in Korea requires special freezers for storage and transportation with extra costs involved. The development of a lyophilization stabilizer for live attenuated duck viral hepatitis virus (DHV) vaccines, therefore, has been highly recommended for the wider application of the vaccines. Four conventional vaccine stabilizer formulations containing a disaccharide, such as lactose, trehalose, or sucrose, and new formulations containing sorbitol were tested for their efficacy in stabilizing a new attenuated DHV type 3 vaccine candidate under different storage temperatures, 4 and 37 degrees C. The vaccine virus and each stabilizer formulation were combined and submitted to lyophilization and the viability of the virus was measured in 7-d-old specific-pathogen-free chicken embryos by determining the 50% egg lethal dose. Stabilizer formulations containing 2, 4, or 8% sorbitol preserved the viability of the vaccine virus much better than the other stabilizer formulations and 2% sorbitol was the optimal concentration in a standard stabilizing buffer, phosphate glutamate gelatin (0.0038 M KH2PO4, 0.0071 M K2HPO4, 0.0049 M monosodium L-glutamate, and 0.5% gelatin). The results demonstrate that the stabilizer formulation containing 2% sorbitol and 0.5% gelatin can be used for convenient storage and transportation of live DHV vaccines.

Kelvin probe force microscopy for conducting nanobits of NiO thin films

We demonstrated the writing and reading of conducting nanobits on a NiO thin film deposited on Pt/TiO(2)/SiO(2)/Si substrates for a resistive random access memory (RRAM) application using conducting atomic force microscopy (CAFM) and Kelvin probe force microscopy (KFM). A Pt/NiO/Pt RRAM capacitor showed a typical unipolar switching behavior with bistable resistances. Conducting nanobits with diameters of 22 nm written with a bias of 3.0 V on the NiO thin film were observed with CAFM. The conducting nanobits observed by KFM exhibited negative potentials relative to the insulating regions when there was no bias at the Pt bottom electrode because image charges were induced by charges formed at the end of the KFM tip by the reference AC bias. Enhancement of the KFM signals for conducting nanobits was achieved using specific biases at the Pt bottom electrode, which provided clear KFM images for conducting nanobits.

Cyberknife stereotactic radiosurgery in patients with primary hepatocellular carcinoma

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Background: Conventional radiotherapy has historically played a limited role in the primary treatment of hepatocellular carcinoma (HCC). This study evaluated the effect of Cyberknife stereotactic radiosurgery (SRS) with for both for small primary non-resectable HCC, and for advanced HCC with portal vein tumor thrombosis (PVTT). Methods: From March 2004 to March 2005, thirty one patients with HCC were treated Cyberknife SRS was used for 32 lesions in patients with SRS for primary HCC. There was performed in 22 patients (23 lesions) with targeting to the primary HCC was treated (Group A), and in 9 patients with targeting to the PVTT was treated (Group B). The total SRS doses treated were 30–39 Gy (median, 36 Gy) to the 70–85%, 3 fractions and the target volume was of 3.6–57.3 cc (median, 25.2 cc). Results: The median follow up was 10.5 months. A complete response (CR) was achieved in 10 lesions, a partial response (PR) in 13 lesions, stable disease was noted in 6 lesions, and disease progression in 3 lesions. The response rate (CR+PR) was 71.9% (group A: 82.6%, group B: 44.4%). The level of serum alpha-fetoprotein after the treatment was decreased significantly in 17 patients (54.8%) (group A: 54.5%, group B: 55.5%). Complications were observed in 15 patients, among them, greater than grade 3 complication was observed in two patients of group A (gastric ulcer bleeding (1), liver necrosis (1)). Conclusions: These results suggest that Cyberknife SRS could be considered as an effective and safe treatment for primary HCC. For PVTT, Cyberknife SRS as the only curative tool, and produced acceptable local control in this study.

No significant financial relationships to disclose.

Clinical analysis of multiple primary cancers

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Background: Multiple primary cancers are defined as two or more abnormal growths of tissue occurring simultaneously or abnormal growths of tissues that follow a previous neoplasm but are not metastases of the latter in the same individual. The primary objective of this study was to determine the occurrence, clinical characteristics and prognosis of multiple primary cancers in single institution, respectively. Methods: Between January 1995 and June 2006, patients with multiple primary cancers were selected from a review of patients who had been treated and followed-up in our Ewha Womans University Hospital. Demographic data were obtained from medical records. Results: Two hundred seven patients were selected and patients with multiple primary cancers constituted 1.95% of all malignancies. Male to female ratio was 1.84. (male 134 vs. female 73 patients) The median age first cancer diagnosis was 67 years old in male, 57 in female. The incidence of synchronous cancers is higher than metachronous. (108 vs. 99) and the median time to additional cancers in metachronous group was 35 months. The most frequent cancers was gastrointestinal cancers in both sex synchronously and metachronously. In male, colorectal cancer followed by gastric cancer methchronously (9.1%), genitourinary cancer with another genitourinary cancer synchronously (12.7%) were frequently observed. In female, breast cancer followed by colorectal cancer metachronously (6.8%), gastric cancer with colorectal cancer (6.9%) were frequently observed. The median survival duration was 14.4 months totally from the index diagnosis and synchronous cancers showed lower survival duration than metachronous cancers. (7.4 vs. 26.1 months, p=0.017) Conclusions: Adequate investigations including G-I tract should focus in the first 3 years after initial diagnosis to detect second primary cancers earlier.

No significant financial relationships to disclose.

TEIN-based Teledermatological Service System among Korea, China and Austria

A teledermatological service system among Korea, China and Austria has been developed and tested in this research. For successful design and establishment of a teledermatological service system, four elements were considered - networking among hospitals and participants, standard specification for teledermatological consultation, database for medical record, and design and implementation of software. In addition to the fundamental stationary system, mobile teledermatological service function using PDA was added to provide dermatologists with ubiquitous consultation service. It was evaluated and proved to be a feasible for teleconsultation system by the dermatologists participated in this research.

A phase II study with gemcitabine and split-dose cisplatin in patients with advanced non-small cell lung cancer

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Background: The combination of gemcitabine and cisplatin is among the most active regimens for the treatment of NSCLC. However, the optimal dose and schedule for administration of the two drugs has not yet been determined. We investigated the activity and toxicity of a gemcitabine and split-dose cisplatin regimen in an outpatient setting for patients with advanced non-small cell lung cancer (NSCLC). Methods: From June 2004 to May 2005 patients with stage IIIB or IV who had not had prior chemotherapy entered the study. Treatment consisted of gemcitabine 1,250 mg/m2 and cisplatin 35 mg/m2, both given intravenously on days 1 and 8 every 21 days. Results: Forty-three patients were entered this study. Patient characteristics were as follows: male/female, 32/11; median age (range), 63 (30–76) years; ECOG PS 0/1/2, 7/28/8; stage IIIB/IV, 17/26. A total of 160 cycles were delivered, with a median of 4 cycles (range, 1–6). All patients were evaluable for toxicity. Grade 3 & 4 toxicities according the NCI toxicity criteria included included neutropenia in 7 patients (17%), anemia in 3 (7%), thrombocytopenia in 6 (14%), and emesis in 1 (2%). Of 40 patients assessable for response, one (2.5%) had CR and 22 (55%) had PR. On intent-to-treat basis, the overall response rate was 53% (95% CI, 39–68%). Median time to progression was 6.0 months (range, 1.2–12.0 months) and median overall survival was 13.1 months (range, 1.4–17 months). Conclusions: This regimen with gemcitabine and split-dose cisplatin using a 21-day schedule appears to be active and very well-tolerated in an outpatients setting for patients with advanced NSCLC.

No significant financial relationships to disclose.

HTLV-1 induced molecular mimicry in neurological disease

As a model for molecular mimicry, we study patients infected with human T-lymphotropic virus type 1 (HTLV-1) who develop a neurological disease called HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP), a disease with important biological similarities to multiple sclerosis (MS) (Khan et al. 2001; Levin et al. 1998, 2002a; Levin and Jacobson 1997). The study of HAM/TSP, a disease associated with a known environmental agent (HTLV-1), allows for the direct comparison of the infecting agent with host antigens. Neurological disease in HAM/TSP patients is associated with immune responses to HTLV-1-tax (a regulatory and immunodominant protein) and human histocompatibility leukocyte antigen (HLA) DRB1*0101 (Bangham 2000; Jacobson et al. 1990; Jeffery et al. 1999; Lal 1996). Recently, we showed that HAM/TSP patients make antibodies to heterogeneous nuclear ribonuclear protein A1 (hnRNP A1), a neuron-specific autoantigen (Levin et al. 2002a). Monoclonal antibodies to tax cross-reacted with hnRNP A1, indicating molecular mimicry between the two proteins. Infusion of cross-reactive antibodies with an ex vivo system completely inhibited neuronal firing indicative of their pathogenic nature (Kalume et al. 2004; Levin et al. 2002a). These data demonstrate a clear link between chronic viral infection and autoimmune disease of the central nervous system (CNS) in humans and, we believe, in turn will give insight into the pathogenesis of MS.

Characteristics of sludge reduction in an integrated pretreatment and aerobic digestion process

In this study, integrated pretreatments and aerobic digestion processes were investigated in order to provide a feasible alternative that can achieve effective sludge reduction. An ozone treatment in the presence of ionic manganese, a catalyst, increased the sludge reduction ratio three times higher than that of a single ozonation, presumably due to an increase in OH radical production. The ozone treatment yielded the effective sludge reduction ratio with an increasing ozone dosage, and an effective dosage of the catalyst was found to be 4 mg-Mn/g-TS. When a mechanical pretreatment and an ozone/catalyst were applied in a series, the integrated process, even at a half mechanical intensity and a half level of ozone dosage, showed higher and faster sludge reduction than each single process did. In addition, the integrated pretreatment process showed the highest dewaterability of the treated sludges. A ratio of sludge cake generation, which was newly introduced to quantify overall performance of sludge treatment processes, showed that the integrated pretreatment followed by the aerobic digestion yielded approximately a half of the sludge cake volume compared to the single aerobic digestion. Therefore, the integrated pretreatment can be a feasible method for the effective reduction of total suspended solid and the final volume.

Effects of mixing on fed-batch fermentation of L-ornithine

The effects of mixing on L-ornithine fermentation were studied using an L-arginine auxotrophic mutant of Brevibacterium ketoglutamicum ATCC 21092. Three different modes of fed-batch culture using two different impeller types were studied in a 7 l fermentor. The first two modes of fed-batch culture were carried out in a fermentor equipped with six-flat-blade disk-turbine impellers with top and bottom feeding. The third mode of fed batch culture was carried out using pitched-six-flat-blade disk-turbine impellers with top feeding. The titre of L-ornithine increased up to 1.8 fold with bottom-feeding or when the pitched-six-flat-blade disk-turbine impellers were used compared to when the six-flat-blade disk-turbine impellers with top-feeding were used. It was observed that the mixing time of the limiting nutrients varied significantly depending on both the direction of feeding and the impeller type. Since the profiles of the specific rates of CO2 evolution, oxygen and glucose uptakes were very similar for the three culture modes, it could be reasonably assumed that the microorganism exhibited similar growth rates for each mode used. However, different amino acid producing activities were observed in the three culture modes. From these results it is concluded that the productivity of L-ornithine fermentation is significantly improved by shortening the mixing time of the limiting nutrient in the fermentor.

Hysteresis and the dynamic phase transition in thin ferromagnetic films

Hysteresis and the nonequilibrium dynamic phase transition in thin magnetic films subject to an oscillatory external field have been studied by Monte Carlo simulation. The model under investigation is a classical Heisenberg spin system with a bilinear exchange anisotropy Lambda in a planar thin film geometry with competing surface fields. The film exhibits a nonequilibrium phase transition between dynamically ordered and dynamically disordered phases characterized by a critical temperature T(cd), whose location is determined by the amplitude H0 and frequency omega of the applied oscillatory field. In the presence of competing surface fields the critical temperature of the ferromagnetic-paramagnetic transition for the film is suppressed from the bulk system value T(c) to the interface localization-delocalization temperature T(ci). The simulations show that in general T(cd)<T(ci) for the model film. The profile of the time-dependent layer magnetization across the film shows that the dynamically ordered and dynamically disordered phases coexist within the film for T<T(cd). In the presence of competing surface fields, the dynamically ordered phase is localized at one surface of the film.

Psychometric evaluation of the exercise self-efficacy scale among Korean adults with chronic diseases

The purpose of this study was to assess the psychometric properties, appropriateness, and demographic response patterns of an exercise self-efficacy scale for Korean adults with chronic diseases. After assessment of face validity by an expert Korean panel, 249 Korean adults with chronic diseases, ages 18-79 years, were recruited from hospitals or health centers in five Korean cities and surrounding rural areas to complete the questionnaire. In a factor analysis the original 18-item exercise self-efficacy scale converged to one factor without rotation and to three subfactors with rotation: situational/interpersonal factor, competing demands factor, and internal feelings factor. Descriptive analysis showed that Korean adults with chronic diseases perceived they had relatively low exercise self-efficacy, with the situational/interpersonal factor as the lowest factor. Exercise self-efficacy was significantly correlated with gender, education, regular exercise, and frequency of exercise. The exercise self-efficacy scale was shown to be a useful measure of exercise beliefs of Korean adults with chronic diseases.

Preoperative detection of hepatocellular carcinoma: ferumoxides-enhanced mr imaging versus combined helical CT during arterial portography and CT hepatic arteriography

OBJECTIVE

The purpose of this study was to compare ferumoxides-enhanced MR imaging with combined helical CT during arterial portography and CT hepatic arteriography for preoperative detection of hepatocellular carcinomas.

SUBJECTS AND METHODS

Twenty patients with 30 hepatocellular carcinomas underwent ferumoxides-enhanced MR imaging and combined helical CT during arterial portography and CT hepatic arteriography. The diagnosis was established by pathologic examination after surgical resection in 18 patients and by biopsy in two. The MR protocol included fast spin-echo with two echo times, T2(*)-weighted fast multiplanar gradient-recalled acquisition in the steady state, proton density-weighted fast multiplanar spoiled gradient-recalled echo, and T1-weighted fast multiplanar spoiled gradient-recalled echo images. The MR images of all sequences and the paired CT during arterial portography and CT hepatic arteriography images were independently evaluated by three radiologists on a segment-by-segment basis. Diagnostic accuracy was assessed with receiver operating characteristic analysis.

RESULTS

The accuracies (A(z) values) of ferumoxides-enhanced MR imaging and combined CT during arterial portography and CT hepatic arteriography for all observers were 0.964 and 0.948, respectively. The mean sensitivities of MR imaging and CT were 93% and 91%, respectively. The differences were not statistically significant. The mean specificity of MR imaging (99%) was significantly higher than that of combined CT during arterial portography and CT hepatic arteriography (94%).

CONCLUSION

Ferumoxides-enhanced MR imaging can be used successfully in place of combined CT during arterial portography and CT hepatic arteriography for the preoperative evaluation of patients with hepatocellular carcinomas.

Detection and identification of mycobacteria by amplification of the internal transcribed spacer regions with genus- and species-specific PCR primers

We evaluated the usefulness of PCR assays that target the internal transcribed spacer (ITS) region for identifying mycobacteria at the species level. The conservative and species-specific ITS sequences of 33 species of mycobacteria were analyzed in a multialignment analysis. One pair of panmycobacterial primers and seven pairs of mycobacterial species-specific primers were designed. All PCRs were performed under the same conditions. The specificities of the primers were tested with type strains of 20 mycobacterial species from the American Type Culture Collection; 205 clinical isolates of mycobacteria, including 118 Mycobacterium tuberculosis isolates and 87 isolates of nontuberculous mycobacteria from 10 species; and 76 clinical isolates of 28 nonmycobacterial pathogenic bacterial species. PCR with the panmycobacterial primers amplified fragments of approximately 270 to 400 bp in all mycobacteria. PCR with the M. tuberculosis complex-specific primers amplified an approximately 120-bp fragment only for the M. tuberculosis complex. Multiplex PCR with the panmycobacterial primers and the M. tuberculosis complex-specific primers amplified two fragments that were specific for all mycobacteria and the M. tuberculosis complex, respectively. PCR with M. avium complex-, M. fortuitum-, M. chelonae-, M. gordonae-, M. scrofulaceum-, and M. szulgai-specific primers amplified specific fragments only for the respective target organisms. These novel primers can be used to detect and identify mycobacteria simultaneously under the same PCR conditions. Furthermore, this protocol facilitates early and accurate diagnosis of mycobacteriosis.

Surface-induced ordering in thin uniaxial liquid crystal films

The interface localization transition in thin uniaxial liquid crystal films with competing surface fields has been studied using Metropolis Monte Carlo simulations. The model is constructed from a lattice of continuously orientable interacting spins, and the Hamiltonian contains both bilinear and biquadratic contributions. The biquadratic contribution to the Hamiltonian is familiar from the Lebwohl-Lasher model, and accounts for the particle anisotropy in a liquid crystal. The head-tail asymmetry of the molecules in a uniaxial liquid crystal is taken into account through a bilinear contribution familiar from the classical ferromagnetic Heisenberg model with exchange anisotropy Lambda. The critical temperature T(c), characterizing the interface localization transition within the uniaxial liquid crystal film, depends strongly on the relative magnitudes of the bilinear and biquadratic interactions between the spins. For systems dominated by the biquadratic interaction, T(c) is found to be close to the bulk critical temperature of the system. But as the biquadratic interaction strength is reduced, T(c) departs markedly from the bulk critical temperature of the system.

A patient with genetic deletion of glutathione-S-transferase T1 and M1 who developed non-small-cell lung cancer and myelodysplastic syndromes

Glutathione S-transferase (GST) M1 polymorphism is a marker for susceptibility to smoking-related neoplasms, such as lung and bladder cancer. Recently, a genetic deletion of GSTT1, an isoenzyme of GST, has been reported to be associated with myelodysplastic syndromes (MDS). A 59-year-old man with a long-term smoking habit was treated successfully for non-small-cell lung cancer. Four years after the surgical removal of his lung cancer, he developed MDS and died. Using a polymerase chain reaction-based genotyping method, he was found to have a deletion of both the GSTM1 and GSTT1 genes. Screening for the deletion of the GSTM1 and GSTT1 genes may be useful for assessing individual genetic susceptibility to smoking-related lung cancer and MDS.

Safety, tolerability, and pharmacokinetics of SR 49059, a V1a vasopressin receptor antagonist, after repeated oral administration in healthy volunteers

The conventional evaluation of safety and tolerability during Phase I may not be sufficient for new exploratory non-peptide receptor antagonists as selective vasopressin (AVP) receptor antagonists. Previous research and validation of surrogate markers considerably enhance the understanding of phase I, and may even contribute with high accuracy to an early approach of dose finding. SR 49059 is a new potent and selective non peptide AVP-antagonist, with high affinity, selectivity and efficacy towards both animal and human AVP-V1a receptors. The aim of this study was to assess its tolerability and to determine both its pharmacokinetic and pharmacodynamic profiles. The safety and tolerability of SR 49059 was assessed in an ascending repeated dose tolerability trial, double-blind for each dose. 50 healthy subjects non smoker males, divided into 5 groups (doses) of 10 were included, (8 treated/2 placebo per group) and received oral doses of either 1, 10, 100, 300 or 600 mg of SR 49059 o.d. for 7 days. Clinical tolerability and biological safety was excellent for all subjects up to the highest dose of 600 mg SR 49059 appeared to have no action on AVP plasma level, hemostasis parameters, nor on blood pressure, heart rate, ECG, diuresis or plasma/urine osmolality. Two previously validated surrogate markers using exogenous vasopressin were sufficient to provide evidence of the V1a antagonistic effects of SR 49059 after the first single oral administration, and during the 7 days of treatment: Ex-vivo AVP induced platelet aggregation inhibition: SR 49059 has shown potent antagonistic properties in inhibiting AVP-induced human platelet aggregation in vitro (IC50 = 3.7 nM). Using this ex vivo qualitative test, a dose and time proportional activity was observed at doses as low as 10 mg, and an almost complete inhibition was demonstrated from 100 mg and above, from Day 1 with a steady state level of inhibition from Day 4 up to Day 7. AVP induced blanching skin area inhibition: Intradermic administration of AVP 0.1 ml (25 ng) produced a measurable vasoconstriction (computer analysis of blanching area), which was also dose dependently antagonised by the oral administration of SR 49059 with the same profile as for platelet-aggregation inhibition. Steady state SR 49059 levels were achieved on days 4-5 with moderate (1.8-2.4 fold) accumulation (t1/2: 32 hrs). Cmax values were in the range 0.8-30 ng/ml. The IC50 of AVP (50 nM) -induced platelet aggregation and cutaneous blanching effect were 2.1 +/- 0.7 nM (1.3 ng/mL) and 4.6 +/- 2.5 nM (2.8 ng/mL), respectively.

CONCLUSIONS

During early phase I, in addition to the conventional safety profile, validated surrogate markers may provide evidence of activity for selective vasopressin receptor antagonists. The results confirmed that SR 49059 is in human a specific V1a-antagonist without activity at V2 receptors, with a good safety profile.

The incidence of the factor V Leiden mutation in an obstetric population and its relationship to deep vein thrombosis

OBJECTIVE

A common missense mutation in the factor V gene, the Leiden mutation, renders factor Va resistant to cleavage inactivation by activated protein C and predisposes patients to thrombotic events. We sought to evaluate the prevalence of the Leiden mutation and the associated thromboembolic events in a community hospital's low-risk obstetric population.

STUDY DESIGN

Deoxyribonucleic acid was extracted from whole blood of 407 women. The polymerase chain reaction was used to amplify exon 10 of the factor V gene, followed by enzymatic digestion with MnI 1 for mutation detection. Medical charts were reviewed and patient characteristics, including age, gravidity, parity, obstetric complications, medical complications, and mode of delivery, were recorded.

RESULTS

Fourteen of the 407 women carried the factor V Leiden mutation (13 heterozygotes and 1 homozygous mutant) for an allele frequency of 3%, consistent with the published carrier rate. Four of the 14 carriers (28%) had deep venous thrombosis, whereas the frequency of deep venous thrombosis in this obstetric population was <1%. Another patient carrying the mutation had a consumptive coagulopathy of unknown etiology at 20 weeks' gestation, necessitating delivery.

CONCLUSIONS

The Leiden mutation is relatively common in the general obstetric population. The high rate of deep venous thrombosis noted in our series suggests the need for genetic testing for this mutation in women with a thrombotic event during pregnancy.

Setaria marshalli infection in neonatal calves

A total of 50 filariid worms of Setaria spp. was recovered from the peritoneal cavity of three neonatal calves infected with the Akabane virus. The parasites were identified as S. marshalli by their morphological characteristics. Males were 41-52 mm long and females 68-98 mm. Most of them were fully matured, indicating that the calves were infected prenatally. This is the first report of prenatal infection in calves by S. marshalli in Korea.

A compartmental model predicts that dietary potassium affects lithium dynamics in rats

Lithium is the treatment of choice for manic depression, but therapy often results in nephrogenic diabetes insipidus and lithium intoxication. To investigate the effects of dietary potassium on potential side effects of lithium therapy, a mathematical model was built using the modeling program SAAM (Simulation, Analysis, And Modeling). Experimental data modeled were from adult male Sprague-Dawley rats fed diets with or without lithium and one of three levels of potassium for 17 d. A five-compartment model of lithium dynamics was built that was consistent with data from rats fed a lithium-containing diet adequate in potassium. This model was then compared with data from rats fed the other two lithium-containing diets. The model predicts that both the fractional transfer coefficient and rate of transport of lithium to the serum compartment from the kidney compartment are lower in rats fed the potassium-adequate diet than in those fed the potassium-deficient diet, and even lower in those fed the potassium-supplemented diet. In addition, fractional transfer coefficients into the serum compartment from the sampled and simulated tissue compartments changed differently with time depending on the amount of dietary potassium. The model also predicts that there would be less accumulation of lithium in the kidney, sampled tissue and simulated tissue compartments with supplemental dietary potassium. The model suggests that potassium supplementation, after a 7-d delay, protects against nephrogenic diabetes insipidus and the potentially toxic accumulation of lithium by decreasing the reabsorption of lithium from the kidneys and increasing lithium efflux from the tissues.