Measurements of the proton elastic-form-factor ratio mu pG p E/G p M at low momentum transfer

High-precision measurements of the proton elastic form-factor ratio, mu pG p E/G p M, have been made at four-momentum transfer, Q2, values between 0.2 and 0.5 GeV2. The new data, while consistent with previous results, clearly show a ratio less than unity and significant differences from the central values of several recent phenomenological fits. By combining the new form-factor ratio data with an existing cross-section measurement, one finds that in this Q2 range the deviation from unity is primarily due to G p E being smaller than expected.

Identification of novel HLA-G subtype, HLA-G*0109, by sequencing in the Korean population

We identified the novel human leukocyte antigen-G*0109 allele in the Korean population by direct sequencing. This allele has a single-nucleotide substitution at nucleotide residue 547 in codon 159 that results in an amino acid change from tyrosine to histidine.

18F-FDG uptake on positron emission tomography in gefitinib-treated non-small cell lung cancer patients

18136

Background: This study evaluated the clinical significance of 18F-fluoro-2-deoxy-glucose (FDG) uptake on positron emission tomography (PET) in gefitinib-treated non-small-cell lung cancer (NSCLC) patients. Method: We retrospectively analyzed PET scans of 66 NSCLC patients with stage IIIB-IV and its association with gefitinib responsiveness. Response rate and time-to- progression (TTP) were analyzed according to the maximum standardized uptake value (SUV) at presentation. Cut-off vale of SUV was obtained from receiver operating characteristic analysis. Univariate and multivariate analyses were performed. Results: According to smoking history and pathology, different response rates were observed (P = 0.012 and 0.048, respectively). Thirteen patients were categorized into low SUV group. Patients with low SUV showed higher RR compared with those with high SUV (46% vs 13%, P = 0.007). In univariate analysis, prolonged TTP was observed in never-smoker (P = 0.007). Low SUV was associated with prolonged TTP (P = 0.010). Multivariate analysis confirmed that low SUV and never-smoker remained favorable prognostic factors (P = 0.046 and 0.043, respectively). Conclusion: These results suggest that FDG uptake may be predictive of outcome in gefitinib-treated non-small-cell lung cancer patients.

No significant financial relationships to disclose.

Phase I/II study of combination chemotherapy with S-1 and cisplatin every 3 week schedule in patients with metastatic or recurrent gastric cancer

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Background: S-1 plus cisplatin has been reported to be highly active in advanced gastric cancer (AGC). The objectives of this study were to define the maximal-tolerated dose (MTD) of S-1, given for 2 weeks separated by 1 week rest, with a fixed dose of cisplatin, and to determine the activity and safety of this combination regimen at the recommended dose (RD) when used as the first line treatment of AGC. Methods: Cisplatin was fixed at a dose of 60 mg/m2 on D1 and the starting dose of S-1 was 30 mg/m2 bid (level I) on D1 to D14 every 3 weeks. The dose of S-1 was increased by 5 mg/m2 bid up to 50 mg/m2 bid (level V) unless MTD was achieved. At every level, a cohort of 3 patients (pts), which could be expanded to 6 pts, was studied. Dose-limiting toxicities (DLTs) were assessed for the first 2 cycles. Results: From February 2004 to January 2006, 62 eligible pts were enrolled. In phase I (N=21), DLTs occurred at level V (S-1 50 mg/m2 bid), with 2 of 3 pts developing G3 diarrhea or febrile neutropenia. The RD was determined at level IV (45 mg/m2 bid) because only 1 DLT occurred out of 6 pts at this level. After the first 20 pts (series I) were enrolled in phase II, the protocol was amended; the S-1 dose was reduced down to 40 mg/m2 bid (level III, series II, N=23) because of poor bone marrow recovery and resultant treatment delay. At the time of analysis, a total of 272 cycles of chemotherapy were administered. The median age was 52 years (28–70) and ECOG PS was 0/1 in 98% of pts. The objective response was observed in 20(47%; 95% CI, 36–66%) of 43 pts. SD was achieved in 15 (35%) pts. With a median FU of 12.1 months (range 9.8–23.3) for all survivors, median PFS was 5.3 months (95% CI, 4.6–6.0 months) with a median OS of 10.0 months (95% CI, 5.1–14.8 months). G3–4 toxicities included neutropenia (33%), anemia (31%), anorexia (24%), and asthenia (14%); however severe febrile neutropenia, abdominal pain, and stomatitis were never observed. Conclusions: The cisplatin plus S-1 regimen incorporating 2-weeks on and 1-week off is highly active against gastric adenocarcinoma with favorable toxicitiy profiles in Korean patients.

No significant financial relationships to disclose.

A new protein crystallization system with large number of cells

A protein crystallization system with large number of cells for vapor and liquid/liquid diffusion was developed for crystallization of protein and other macromolecules in space. It has high ratio of cell number over system dimension or mass. A facility with it can save the space resource and suitable for boarding of many kinds of spacecraft.

158 LEADING BLASTOMERE OF A 2-CELL-STAGE PORCINE PARTHENOGENETIC EMBRYO CONTRIBUTES TO TROPHECTODERM FIRST

Embryonic axis formation is important in normal animal development. Some vertebrate and invertebrate eggs display undeniable polarity along a plane known as the animal–vegetal axis. However, axis formation in mammals, which is studied only in mice, is still a point of issue (Hiiragi and Solter 2004 Nature 430, 360–364; Zernicka-Goetz et al. 2005 Nature 434, 391–395). In the present study, we investigated the embryonic–abembryonic axis formation in porcine species. We used porcine parthenogenetic embryos to prevent a topological change of the 2 apposing pronuclei in the egg center caused by polyspermy and to avoid the influence of the fertilization cone, which indicates the sperm entry position. For lineage tracing, DiI, a lipophilic fluorescence dye, was injected into one blastomere per embryo at the 2-cell stage. After this process, as embryos developed into the 3-cell stage, all the embryos were divided into 2 groups named Leading and Lagging, following the location of the DiI oil drop (Leading: the oil drop was positioned in the first-dividing blastomere; Lagging: the drop was positioned in the late-dividing blastomere). The embryos developed into blastocysts after 6 to 7 days of culture in vitro. Only the inner cell mass (ICM) was labeled in 50% (8/16) of the Lagging group. In some Lagging embryos (2/16), ICMs with a small portion of adjacent trophectodermal cells (TE) were labeled and 62.5% (10/16) of Lagging embryos formed the ICM part in total. On the other hand, 60% (6/10) of the Leading embryos formed only distal TE (opposite side of the ICM). Only one of the Leading embryos formed the ICM. The rest of Lagging embryos (37.5%, 6/16) or the Leading group (40.0%, 4/10) showed an even distribution of blastocysts, regardless of the ICM or TE. Oocytes, zygotes, and 2-cell-stage embryos in porcine species tended to show unequally distributed lipid contents and could be distinguished by their different colors and brightness, although not all of them showed significant differences. We injected DiI into a relatively brighter blastomere of the 2-cell-stage embryos and the results were very similar to those obtained from the Leading group (distal TE: 70.6%, 24/34). High lipid contents may be the cause of delayed development of the blastomere of an embryo. Our findings indicated that the Leading blastomere of 2-cell porcine parthenotes formed distal TE first, and that afterward, the Lagging blastomere not only filled the rest of the TE but also contributed to the ICM. This study was supported by the Research Project on the Production of Bio-organs (No. 200506030601) and Technology Developmental Program (High-Technology Development Project No. 204117-3) for Agriculture and Forestry, Ministry of Agriculture and Forestry, Republic of Korea

Biomechanical responses of human temporomandibular joint disc under tension and compression

The purpose of this study was to observe the microscopic changes in the temporomandibular joint (TMJ) disc in response to tension and compression, and to study the mechanism of disc failure when subjected to mechanical stresses. The scanning electron microscope was used to observe topographic characteristics of TMJ disc samples obtained from 13 cadavers before and during biomechanical experiments. The stress relaxation experiments were conducted at different strain levels (2, 3, 4 and 6%). The uniaxial tensile experiments were carried out at a constant strain rate (0.05 mm/s). The confined compression tests were performed with 3 different indenters (2, 3 and 4mm in diameter) for 150 s and 3 h. The maximal tensile strain of the disc was 5% (nearly equal to 0.22 MPa of tensile stress) in the mediolaterally tensile direction. Typical wavelike structure of the collagen fibrils of the disc was present at 2-4% strain ranges. Tensile and shear damage to local collagen fibrils was observed in specimens of the intermediate zone and the posterior band at 6% strain level. Changes in the collagen network from a wavelike structure to distortion observed on the surface of the testing samples were reversible in the 150-s indentation, but severe, irreversible breakdown and deformation of the collagen-proteoglycan network occurred in those specimens that had been compressed for 3h. Persistent and prolonged compression inevitably resulted in irrecoverable disc failure. Mechanical stress is a crucial factor in breakdown of the TMJ disc.

Possible role of Fas/Fas ligand-mediated apoptosis in the pathogenesis of fixed drug eruption

BACKGROUND

Although epidermal and dermal T cells play roles in the pathogenesis of fixed drug eruption (FDE), not much is known about keratinocyte death and its precise mechanism in FDE.

OBJECTIVES

Our aim is to elucidate the mechanism that underlies keratinocyte death in FDE, that is, the role of apoptosis and its signalling pathway.

METHODS

We first examined the involvement of apoptosis in the active FDE lesions by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end-labelling (TUNEL) assay and immunohistochemical analysis of caspase-3. We then examined the expressions of Fas and Fas ligand (FasL) to deduce the possible upstream signalling pathway of apoptosis, if apoptosis were involved. We finally characterized the infiltrated T-cell subpopulations in the active FDE lesions.

RESULTS

In the active FDE lesions, TUNEL positivity was strongly observed in the basal keratinocytes, and also weakly observed in the upper dermal infiltrates as well as in a few keratinocytes in the granular layer. The distribution of TUNEL-positive cells was similar to that of the strong staining of active capase-3. Fas was found mainly in the keratinocytes and some infiltrated dermal cells, whereas FasL was identified predominantly in the intraepidermal and dermal infiltrated cells and in some basal keratinocytes. Overlapping expression of Fas and FasL was accompanied by apoptosis in the FDE lesions. Many of the infiltrated mononuclear cells were CD8+. Perforin was rarely observed in the FDE lesions.

CONCLUSIONS

These findings suggest that apoptosis of the keratinocyte is highly likely to be involved in the pathogenesis of FDE, and this cytotoxicity might be predominantly mediated by the FasL of the infiltrating CD8+ T cells, possibly also playing an inflammatory role.

EGFR mutations and human papillomavirus in squamous cell carcinoma of tongue and tonsil

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Background: Some studies reported the presence of somatic mutation of EGFR in head and neck cancer. Human papillomavirus (HPV) was associated with some types of head and neck cancer. We performed this study to determine clinical significance of EGFR mutation and its association with HPV infection in patients with tongue and tonsil cancer. Methods: We sequenced exons 18–21 of EGFR TK domain and HPV typing was performed using the HPV DNA chip in tissues of patients with tongue and tonsil cancer. Univariate and multivariate analysis was performed. Results: Eighty-one patients were included. We detected EGFR mutation in 10 (12%) patients. Mutation was significantly frequent in never-smoker (21% versus 5%; P = 0.031). The mutation frequency did not differ between tongue and tonsil cancer (12% vs. 13%, respectively; P = 0.978). There was no difference between female and male (12% vs. 14%, respectively; P = 0.754). Eleven of 81 (14%) patients were HPV positive. HPV positivity was more common in young (<60 years) than older (≥60 years) patients (20% vs. 3%, respectively; P = 0.039). Patients with tonsil cancer showed more frequent HPV positivity than tongue cancer (42% vs. 2%, respectively; P < 0.001). There was no association between HPV positivity and EGFR mutation. In terms of disease-free survival, patients with EGFR mutation had better survival independently of stage and primary site (hazard ratio, 0.246; 95% CI, 0.075 to 0.802). Conclusions: We did not find association between EGFR mutation and HPV positivity. Patients with EGFR mutation showed better outcome in tongue and tonsil cancer. These results suggest that EGFR mutation may be a prognostic factor in patients with head and neck cancer.

No significant financial relationships to disclose.

Photoinduced processes in protonated tryptamine

The electronic excited state dynamics of protonated tryptamine ions generated by an electrospray source have been studied by means of photoinduced dissociation technique on the femtosecond time scale. The result is that the initially excited state decays very quickly within 250 fs. The photoinduced dissociation channels observed can be sorted in two groups of fragments coming from two competing primary processes on the singlet electronic surface. The first one corresponds to a hydrogen-atom loss channel that creates a tryptamine radical cation. The radical cation subsequently fragments to smaller ions. The second process is internal conversion due to the H-atom recombination on the electronic ground state. Time-dependent density functional theory calculations show that an excited pisigma* state dissociative along the protonated amino N-H stretch crosses both the locally excited pipi* state and the electronic ground state S(0) and thus triggers the photofragmentation reactions. The two processes have equivalent quantum yields, approximately equal to 50% of the fragments coming from the H-atom loss reaction. The two primary reaction paths can clearly be distinguished by their femtosecond pump/probe dynamics recorded on the different fragmentation channels.

Comparative proteome analysis of rat brain and coronary microvascular endothelial cells

The endothelium of different organs displays a remarkable heterogeneity, although it presents many common functional and morphological features. However, despite our knowledge of heterogeneity among endothelial cells from different sites, the differences between brain microvascular endothelial cells (BMEC) and coronary microvascular endothelial cells (CMEC) are poorly defined. The aim of this study was to investigate whether BMEC are distinct from CMEC at the protein level. Using the proteomic approach, we comparatively analyzed the proteome of cultured BMEC and CMEC. We reproducibly separated over 2000 polypeptides by using two-dimensional electrophoresis (2-DE) at pH range of 3-10. Using PDQuest software to process the 2-DE gel images, forty-seven protein spots were differentially expressed in the two-endothelial cells. Of these, thirty-five proteins are highly expressed in BMEC, whereas twelve proteins are highly expressed in CMEC. Fifteen proteins in BMEC and seven proteins in CMEC were identified with high confidence by matrix-associated laser desorption ionization time-of-flight mass spectrometer (MALDI-TOF-MS). Our data suggested that BMEC and CMEC were different in several aspects including cytokine and growth-related molecules, stress-related proteins, metabolic enzymes, signal transduction proteins and others. The identification of a set of proteins preferentially expressed in BMEC and CMEC provided new data on the heterogeneity of the endothelium.

N-acetylphytosphingosine-induced apoptosis of Jurkat cells is mediated by the conformational change in Bak

N-acetylphytosphingosine (NAPS), a sphingolipid derivative, is one of the well-known signal molecules that mediates various cellular functions, including cell growth, differentiation, and apoptosis. In this study, we demonstrated that NAPS induces apoptosis of Jurkat cells by activating Bak, but not Bax, which are both members of a proapoptotic subfamily of the Bcl-2 proteins. NAPS activated caspase-8 in a FADD-independent manner, but the lack of caspase-8 did not suppress the activation of caspase-3 and -9 and cell death, indicating that caspase-8 activation does not play an important role in NAPS-induced cell death. The overexpression of Bcl-xL, an anti-apoptotic protein, completely inhibited the activation of the caspases and apoptosis, assuming that NAPS-induced apoptosis was initiated by the mitochondria. The expression levels of pro- and anti-apoptotic Bcl-2 family members were not changed by the NAPS treatment. However, Bad was translocated from the cytosol into the mitochondria, where it bound to Bcl-xL, and Bak was dissociated from Bcl-xL and conformationally changed. Taken together, these findings indicate that NAPS induced apoptosis of Jurkat cells in a mitochondria-dependent manner that was controlled by the translocation of Bad and the conformational change in Bak.

Glucose metabolism and oscillatory behavior of pancreatic islets

A variety of oscillations are observed in pancreatic islets. We establish a model incorporating two oscillatory systems of different time scales: One is the well-known bursting model in pancreatic cells and the other is the glucose-insulin feedback model which considers direct and indirect feedback of secreted insulin. These two are coupled to interact with each other in the combined model, and two basic assumptions are made on the basis of biological observations: The conductance gK(ATP) for the ATP-dependent potassium current is a decreasing function of the glucose concentration whereas the insulin secretion rate is given by a function of the intracellular calcium concentration. Obtained via extensive numerical simulations are complex oscillations including clusters of bursts, slow and fast calcium oscillations, and so on. We also consider how the intracellular glucose concentration depends upon the extracellular glucose concentration, and examine the inhibitory effects of insulin.

Resonant nernst effect in the metallic and field-induced spin density wave States of (TMTSF)2ClO4

We examine an unusual phenomenon where, in tilted magnetic fields near magic angles parallel to crystallographic planes, a "giant" resonant Nernst signal has been observed by Wu et al. [Phys. Rev. Lett. 91, 056601 (2003)] in the metallic state of an organic conducting Bechgaard salt. We show that this effect appears to be a general feature of these materials and is also present in the field-induced spin density wave phase with even larger amplitude. Our results place conditions on any model that treats the metallic state as a state with finite Cooper pairing.

Statistical vs. non-statistical deactivation pathways in the UV photo-fragmentation of protonated tryptophan-leucine dipeptide

The excited state dynamics of protonated tryptophan-leucine ions WLH+, generated in an electrospray source, is investigated by photo-induced fragmentation in the gas phase, using femtosecond laser pulses. Two main features arise from the experiment. Firstly, the initially excited pipi* state decays very quickly with 2 time constants of 1 and 10 ps. Secondly, the transient signals recorded on different fragments are not the same which indicates two competing primary fragmentation processes. One involves a direct dissociation from the excited state that gives evidence for a non-statistical deactivation path. The other is attributed to a statistical decay following internal conversion to the ground electronic surface.

Birth month and sensitization to house dust mites in asthmatic children

BACKGROUND

Early exposure to high quantities of allergen has an important role in the incidence of atopic sensitization. In fact, subjects sensitized to house dust mites (HDMs) have a significantly higher proportion of births in the season when HDMs are most abundant.

OBJECTIVE

The aim of this study was to investigate whether birth month patterns differ for asthmatic patients sensitized only to HDMs and for those sensitized to HDMs and other allergen(s).

METHODS

Among 2225 patients with asthma, aged 10-16 years, 1642 sensitized to HDMs were identified by skin prick testing. This group was composed of patients sensitized only to HDMs (n = 715) and patients sensitized to HDMs and other allergen(s) (n = 927). The birth month distributions of the group of HDM-sensitive asthmatics or its subgroups were compared with that of a reference population (total live births in the same years as the studied subjects). The risk ratio of a given birth month in relation to all the other months was calculated as an odds ratio (OR) with the corresponding 95% confidence interval (CI).

RESULTS

A significant difference in birth month distribution was observed for HDM-sensitive asthmatics (chi(2) = 23.6, P = 0.015), with higher rates of birth in August (OR: 1.23, 95% CI: 1.04-1.46) and September (1.24, 1.04-1.46). When the two subgroups were analyzed separately, significantly more births were noted in August (1.34, 1.06-1.71) and September (1.34, 1.05-1.70) for those sensitized only to HDMs, whereas no such birth month preference was observed for those sensitized to HDMs and other allergen(s).

CONCLUSIONS

The HDM-positive asthmatics showed a greater proportion of births in August and September, which correspond to high HDM exposure. However, this birth month pattern was evident in asthmatic-sensitive only to HDMs, but was not observed in those sensitive to HDMs and other allergen(s).