Near-threshold photoproduction of Lambda(1520) from protons and deuterons

Photoproduction of Lambda(1520) with liquid hydrogen and deuterium targets was examined at photon energies below 2.4 GeV in the SPring-8 LEPS experiment. For the first time, the differential cross sections were measured at low energies and with a deuterium target. A large asymmetry of the production cross sections from protons and neutrons was observed at backward K+/0 angles. This suggests the importance of the contact term, which coexists with t-channel K exchange under gauge invariance. This interpretation was compatible with the differential cross sections, decay asymmetry, and photon beam asymmetry measured in the production from protons at forward K+ angles.

Cross sections and beam asymmetry for K;{+}Sigma;{*-} photoproduction from the deuteron at E_{gamma}=1.5-2.4 GeV

The Sigma(1385) resonance, or Sigma;{*}, is well known as part of the standard baryon decuplet with spin J=3/2. Measurements of the reaction gammap-->K;{+}Sigma;{*0} are difficult to extract due to overlap with the nearby Lambda(1405) resonance. However, the reaction gamman-->K;{+}Sigma;{*-} has no overlap with the Lambda(1405) due to its charge. Here we report the first measurement of cross sections and beam asymmetries for photoproduction of the Sigma;{*-} from a deuteron target. The cross sections at forward angles range from 0.4 to 1.2 mub, with a broad maximum near E_{gamma} approximately 1.8 GeV. The beam asymmetries are negative, in contrast with positive values for the gamman-->K;{+}Sigma;{-} reaction.

Purinergic P2X receptor activation induces emetic responses in ferrets and Suncus murinus (house musk shrews)

BACKGROUND AND PURPOSE

Despite the rapid progress made in understanding the significant role played by signalling via extracellular ATP in physiology and pathology, there has been no clear information generated on its involvement in the emetic response.

EXPERIMENTAL APPROACH

In the present study, the emetogenic potential of extracellular ATP signalling in mammalian species was examined using ferrets and Suncus murinus (house musk shrews). A slowly degradable ATP analogue, alpha,beta-methyleneATP (alpha,beta-meATP), was used to activate the P2X receptors, and either the non-selective P2 receptor antagonist, pyridoxal phosphate-6-azophenyl-2',4'-disulphonic acid (PPADS), or the specific P2X(3) homomer and P2X(2/3) heteromer antagonist, A-317491, were tested against the agonist-induced response.

KEY RESULTS

Intraperitoneal injection of alpha,beta-meATP produced significant emetic responses in ferrets (1 - 30 mg kg(-1)) and in Suncus murinus (5 - 50 mg kg(-1)). The responses occurred frequently within the first 10 min after administration, much less frequently from 11 to 60 min and no responses occurred later than 60 min. The emetic responses were completely inhibited by intraperitoneal pre-treatment with PPADS (100 mg kg(-1)) or A-317491 (100 mg kg(-1)). Abdominal surgical vagotomy did not reduce the emetic response in Suncus murinus significantly.

CONCLUSIONS AND IMPLICATIONS

These results for the first time indicate that the activation of P2X receptors evokes emetic responses in mammalian species. The P2X(3) homomer and.or P2X(2/3) heteromer in the area postrema could be responsible for the emetic response. This finding contributes to the elucidation of the roles played by extracellular ATP signalling in various emetic symptoms.

Glucocorticoid receptor activation is involved in producing abnormal phenotypes of single-prolonged stress rats: a putative post-traumatic stress disorder model

Post-traumatic stress disorder (PTSD) is a stress-related mental disorder caused by traumatic experience, and presents with characteristic symptoms, such as intrusive memories, a state of hyperarousal, and avoidance, that endure for years. Single-prolonged stress (SPS) is one of the animal models proposed for PTSD. Rats exposed to SPS showed enhanced inhibition of the hypothalamo-pituitary-adrenal (HPA) axis, which has been reliably reproduced in patients with PTSD, and increased expression of glucocorticoid receptor (GR) in the hippocampus. In this study, we characterized further neuroendocrinologic, behavioral and electrophysiological alterations in SPS rats. Plasma corticosterone recovered from an initial increase within a week, and gross histological changes and neuronal cell death were not observed in the hippocampus of the SPS rats. Behavioral analyses revealed that the SPS rats presented enhanced acoustic startle and impaired spatial memory that paralleled the deficits in hippocampal long-term potentiation (LTP) and depression. Contextual fear memory was enhanced in the rats 1 week after SPS exposure, whereas LTP in the amygdala was blunted. Interestingly, blockade of GR activation by administering 17-beta-hydroxy-11-beta-/4-/[methyl]-[1-methylethyl]aminophenyl/-17-alpha-[prop-1-ynyl]estra-4-9-diene-3-one (RU40555), a GR antagonist, prior to SPS exposure prevented potentiation of fear conditioning and impairment of LTP in the CA1 region. Altogether, SPS caused a number of behavioral changes similar to those described in PTSD, which marks SPS as a putative PTSD model. The preventive effects of a GR antagonist suggested that GR activation might play a critical role in producing the altered behavior and neuronal function of SPS rats.

Dilation of building materials submitted to frost action

This paper presents the results of laboratory frost weathering of five geomaterials used in stone monuments showing more or less frost damage: two sandstones (France), molasses (Switzerland), and a volcanic tuff and brick (Japan). Samples were submitted to unidirectional freezing simulations during which temperature and dilation were measured. The aim of these experiments was to understand which internal or external factors prevailing on dilation would lead to cracking. Results showed that water supply and repetition of freeze-thaw cycles were most important in the dilation of the materials. They also showed that the materials with the weakest transfer properties by capillary absorption were the most sensitive to frost action.

Association of K121Q polymorphism in ENPP1 (PC-1) with BMI in Caucasian and African-American adults

OBJECTIVE

To test for association of the ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) K121Q polymorphism with body mass index (BMI) and diabetes in a large sample of Caucasians and African-Americans by selectively genotyping individuals at the extremes of the phenotypic distribution.

SUBJECTS

Subsets comprising the extremes of the BMI distribution (10th-20th and above the 90th BMI percentile for Caucasians and between the 10th-30th and above the 80th percentile for African-Americans) from a group of 10,260 Caucasian and 2268 African-American adults participating in New York Cancer Project were studied.

METHODS

Subjects were genotyped for the ENPP1 K121Q polymorphism by pyrosequencing and tested for association with BMI and diabetes by regression analysis.

RESULTS

Regression analysis with BMI as the dependent variable demonstrated a significant association (P = 0.02) of genotype at K121Q with BMI, with no significant race-by-genotype interaction (P = 0.30). Compared with Q/Q or Q/K individuals, the K/K individuals had a BMI approximately 1.3 kg/m2 higher, without effects of age, gender or race. By logistic regression analysis, the K121Q alleles had no significant effect on diabetes status (P = 0.37) in obese subjects.

CONCLUSION

In both Caucasians and African-Americans, the K121 polymorphism in ENPP1 was associated with increased BMI, but not with diabetes.

Tacrolimus (FK506) attenuates biphasic cytochrome c release and Bad phosphorylation following transient cerebral ischemia in mice

Tacrolimus (FK506) has a neuroprotective action on cerebral infarction produced by cerebral ischemia, however, detailed mechanisms underlying this action have not been fully elucidated. We examined temporal profiles of survival-and death-related signals, Bad phosphorylation, release of cytochrome c (cyt.c), activation of caspase 3 and DNA fragmentation in the brain during and after middle cerebral artery occlusion (MCAo) in mice, and then examined the effect of tacrolimus on these signals. C57BL/6J mice were subjected to transient MCAo by intraluminal suture insertion for 60 min. Tacrolimus (1 mg/kg, i.p.) was administered immediately after MCAo. There were biphasic increases in the release of cyt.c in the ischemic core and penumbra; with the first increase toward the end of the occlusion period and the second increase 3-12 h after reperfusion. Tacrolimus significantly inhibited the increase of cytosolic cyt.c during ischemia and reperfusion. Phosphorylated Bad, Ser-136 (P-Bad(136)) and Ser-155 (P-Bad(155)) were detected 30 min after MCAo and after reperfusion in the ischemic cortex, respectively. Tacrolimus increased P-Bad(136) during ischemia and prolonged P-Bad(155) expression after reperfusion. Tacrolimus also decreased caspase-3 and terminal deoxynucleotidyl transferase-mediated DNA nick-end labeling-positive cells, and reduced the size of infarct 24 h after reperfusion. Our study provided the first evidence that the neuroprotective action of tacrolimus involved inhibition of biphasic cyt.c release from mitochondria, possibly via up-regulation of Bad phosphorylation at different sites after focal cerebral ischemia and reperfusion.

Differential cross section and photon-beam asymmetry for the gamma n --> K+ Sigma- reaction at E gamma = 1.5-2.4 GeV

Differential cross sections and photon-beam asymmetries have been measured for the gamma n --> K+ Sigma- and gamma p --> K+Sigma0 reactions separately using liquid deuterium and hydrogen targets with incident linearly polarized photon beams of E gamma = 1.5-2.4 GeV at 0.6 < cos ThetacmK< 1. The cross section ratio of sigma K+ Sigma-/sigma K+ Sigma0, expected to be 2 on the basis of the isospin 1/2 exchange, is found to be close to 1. For the K+ Sigma- reaction, large positive asymmetries are observed, indicating the dominance of K* exchange. The large difference between the asymmetries for the K+ Sigma- and K+ Sigma0 reactions cannot be explained by simple theoretical considerations based on Regge model calculations.

Phase 1 study of atrasentan (ABT627), novel endothelin receptor-A antagonist, in Japanese patients with hormone refractory prostate cancer

14602

Background: Endothelin (ET)-1 and its primary receptor, the ETA receptor, contribute to tumor cell growth, survival, angiogenesis and invasion. Atrasentan is a highly potent, selective ETA receptor antagonist. This study assessed safety and pharmacokinetics (PK) in Japanese patients with hormone refractory prostate cancer. Methods: This open-label, single-center Phase I trial evaluated the safety and PK of escalating oral atrasentan doses (2.5, 10 or 20 mg) given daily on day 1 and day 4 through 27 (except day 2 and 3). Dose-limiting toxicity (DLT) was defined as Grade 3 or greater adverse events related to study drug. Results: Eighteen patients, aged 54–74 (median; 66) were treated in cohorts of 6 patients each. The compliance of all patients was 100%. The most common toxicities were rhinitis, peripheral edema, headache, hypotension and anemia, all of which were well tolerated. These events were consistent with the anticipated vasodilatory effects or with a hemodilution effect of the study drug. DLTs were not observed. Atrasentan was rapidly absorbed following oral administration of 2.5 to 20 mg, maximum plasma concentrations averaged from 0.4 to 0.8 hours. After peaking, plasma concentrations declined bi-exponentially with a terminal half-life of approximately 25 hours. In the 10 mg dosing group, the steady-state maximum plasma concentration (Cmax) and the area under the curve (AUC0–24h) averaged 135.5 ng/mL and 533 ng h/mL, respectively. The Cmax and AUC values generally increased linearly with increasing dose after single- and multiple-dose administration. Compared to baseline, PSA decreased 50% or more in 1 patient (20 mg) and increased 25% or more in 10 patients (2.5 mg;2, 10 mg;5, 20 mg;3). The PSA of the remaining 7 patients (2.5 mg;4, 10 mg;1, 20 mg;2) ranged from < 25% increase to < 50% decrease. Fourteen patients continued on study drug in an extension study. Conclusions: Atrasentan is well tolerated, with no dose-limiting adverse events observed up to 20 mg in Japanese patients. The main adverse events are consistent with the vasodilatory effect of the drug. PK are linear and dose-proportional; the half-life is appropriate for once-daily dosing.

No significant financial relationships to disclose.

Adolescents' attachment style and early experiences: a gender difference

We examined gender differences in perceived rearing and adult attachment style in adolescents. A total of 3,912 senior college students (1,149 men and 2,763 women) ages 18-23 (men's M = 20.1 years, women's M = 20.0 years) were administered a set of questionnaires including Relationship Questionnaire (to measure adult attachment), the Parental Bonding Instrument (perceived rearing), and a list of early life events. In the men, positive adult total attachment style was predicted by the scores of paternal care and low scores on maternal overprotection in a hierarchical regression analysis. On the other hand, in the women, positive adult total attachment style was predicted by the scores of paternal and maternal care, and low score on maternal overprotection. Adult attachment was also predicted by fewer Peer Victimization experience as a child in both men and women. However, while men's adult attachment was predicted by Self Disease experiences, women's adult attachment was predicted by Top Star experiences and fewer Relocation experiences. The adult attachment style was predictable from early experiences but there existed some gender differences.

Near-threshold diffractive psi-meson photoproduction from the proton

Photoproduction of a phi meson on protons was studied by means of linearly polarized photons at forward angles in the low-energy region from threshold to Egamma = 2.37 GeV. The differential cross sections at t = -|t|min do not increase smoothly as Egamma increases but show a local maximum at around 2.0 GeV. The angular distributions demonstrate that phi mesons are photoproduced predominantly by helicity-conserving processes, and the local maximum is not likely due to unnatural-parity processes.

Beam-polarization asymmetries for the p(gamma-->, K+)Lambda and p(gamma-->, K+)Sigma(0) reactions for E(gamma)=1.5-2.4 GeV

Beam polarization asymmetries for the p(gamma-->,K+)Lambda and p(gamma-->,K+)Sigma(0) reactions are measured for the first time for E(gamma)=1.5-2.4 GeV and 0.6<cos((theta(c.m.)(K+))<1.0 by using linearly polarized photons at the Laser-Electron-Photon facility at SPring-8 (LEPS). The observed asymmetries are positive and gradually increase with rising photon energy. The data are not consistent with theoretical predictions based on tree-level effective-Lagrangian approaches. Including the new results in the development of the models is, therefore, crucial for understanding the reaction mechanism and to test the presence of baryon resonances which are predicted in quark models but are thus far undiscovered.

Evidence for a narrow S = +1 baryon resonance in photoproduction from the neutron

The gamman-->K(+)K(-)n reaction on 12C has been studied by measuring both K+ and K- at forward angles. A sharp baryon resonance peak was observed at 1.54+/-0.01 GeV/c(2) with a width smaller than 25 MeV/c(2) and a Gaussian significance of 4.6sigma. The strangeness quantum number (S) of the baryon resonance is +1. It can be interpreted as a molecular meson-baryon resonance or alternatively as an exotic five-quark state (uuddsmacr;) that decays into a K+ and a neutron. The resonance is consistent with the lowest member of an antidecuplet of baryons predicted by the chiral soliton model.

Dopamine stabilizes milrinone-induced changes in heart rate and arterial pressure during anaesthesia with isoflurane

BACKGROUND AND OBJECTIVE

Phosphodiesterase-III inhibitors and dobutamine effectively improve cardiac function in patients with cardiac failure, but they are limited by possible hypotensive effects. We tested the hypothesis that dopamine contributes to stabilizing milrinone-induced haemodynamic changes.

METHODS

Nine patients undergoing major surgery were anaesthetized using nitrous oxide and oxygen supplemented with isoflurane 1-2%. After baseline haemodynamics were recorded, milrinone (25 or 50 microg kg(-1)) was administered over 10min, followed by a continuous infusion (0.5 microg kg(-1) min(-1). The second set of haemodynamic values was measured 50 min after beginning the continuous infusion of milrinone. Dopamine (4 microg kg(-1) min(-1)) was then administered with milrinone.

RESULTS

Milrinone significantly increased the heart rate from 81 +/- 8 to 102 +/- 16beats min(-1), but it decreased the mean arterial pressure from 83 +/- 10 to 66 +/- 10 mmHg and systemic vascular resistance (P < 0.05 for each). The pulmonary capillary wedge pressure, cardiac index and pulmonary vascular resistance did not change significantly. The addition of dopamine to the milrinone infusion significantly decreased the heart rate (94 +/- 12 beats min(-1)) and increased the mean arterial pressure (82 +/- 11 mmHg). Dopamine and milrinone, but not milrinone alone, significantly increased the cardiac index and the rate-pressure product.

CONCLUSIONS

The combination regimen of milrinone and dopamine improved cardiac function, and changes in heart rate and mean arterial pressure induced by milrinone were attenuated by dopamine. The results suggest that a combination regimen of milrinone and dopamine rather than milrinone alone should be used to maintain arterial pressure.

[A case of myasthenia gravis accompanied by large thymoma and anti-GAD antibody]

A 61-year-old woman had repeated episodes of muscle weakness of face, neck and limbs for 18 years. She was diagnosed as having myasthenia gravis (MG) by the positive anti-acetylcholine receptor antibody and findings of electromyogram. Simultaneously, she was noticed to have diabetes mellitus with high titers of anti-glutamic acid decarboxylase (GAD) antibody. Magnetic resonance imaging showed a large thymoma. In spite of the improvement of MG after thymectomy, the insulin secretion slowly exacerbated during next two years. The clinical course of her disease was characteristic as slowly progressive insulin dependent diabetes mellitus (SPIDDM). She continued to have positive autoantibody against beta-cell of pancreas. Recently, anti-GAD antibody is detected in patients with SPIDDM and stiffman syndrome (SS) in high rate, and it is closely associated with the cause of these syndromes. The patient did not reveal the symptoms of SS. From the clinical course, MG and SPIDDM in this patient may be caused by a common underlying autoimmune abnormality resulting from the long presence of the thymoma. MG and SPIDDM may be derived from organ-specific autoimmunopathy from the defect of self-tolerance.

Novel immunosuppressive effect of FK506 by augmentation of T cell apoptosis

We have recently reported the accumulation of oligoclonal activated T cells in the spontaneously developed autoimmune pancreatitis in aly/aly mouse. In this study, we examined the effects of FK506 in this mouse model in preventing autoimmune pancreatitis and investigated its action on calcium signalling apoptosis of alymphoplasia (aly) lymphocytes in vitro. Mice were treated with FK506 from 8 to 25 weeks of age. At the age of 15 weeks, minimal mononuclear cell infiltration was observed in the pancreas in both the FK506 treated group and the control group. Furthermore, a marked cell infiltration associated with destruction of acini and partial fatty changes were observed in 25-week-old control mice. In contrast, FK506 treated mice showed almost no tissue destruction or mononuclear cell infiltration at the age of 25 weeks. Furthermore, at 15 weeks of age, most mononuclear cells in FK506-treated mice were TUNEL positive, whereas only a few were positive in control mice. This augmentation of T cell apoptosis by FK506 was confirmed using naive splenocytes activated by PMA and ionomycin in vitro. Finally, a suppressive effect of FK506 on Bcl-2 production but not on Bax production was confirmed by Western blotting. This unique effect of FK506 on the augmentation of T cell apoptosis is probably one of the mechanisms explaining its beneficial effect on aly autoimmune pancreatitis.

Di(2-ethylhexyl)phthalate induces hepatocellular adenoma in transgenic mice carrying a human prototype c-Ha-ras gene in a 26-week carcinogenicity study

To evaluate the transgenic mouse carrying a human prototype c-Ha-ras gene (rasH2 mouse) as a model for 26-week carcinogenicity tests, Di(2-ethylhexyl)phthalate (DEHP), a peroxisome proliferator, was administered to 15 rasH2 mice/sex/group at concentrations of 1,500, 3,000 or 6,000 ppm, and to 15 wild-type (non-Tg) mice/sex/group at a concentration of 6,000 ppm in their diets for 26 weeks. Survival rates and food consumption in the groups treated with DEHP and in the control group were similar. Body weight gain in rasH2 and non-Tg mice at 6,000 ppm in the terminal week decreased about 10% as compared to the control group. Common findings related to treatment with DEHP in rasH2 and non-Tg mice included hypertrophy with coarse granules and deposit of pigment in the liver, hydronephrosis and tubular regeneration in the kidney, focal atrophy in the testis, and increased eosinophilic body in the nasal cavity. Hepatocellular adenoma was induced by treatment with DEHP, and was confined to male rasH2; mice the incidence being 7%(1/15), 13%(2/15), and 27%(4/15) in the 1,500-, 3,000-, and 6,000-ppm group, respectively. Point mutation was not detected in codon 12 and 61 of human c-Ha-ras transgene upon DNA analyses on frozen samples taken from these hepatocellular adenomas. From the results obtained in this 26-week carcinogenicity study, it is concluded that DEHP is a hepato-carcinogen for transgenic mouse carrying a human prototype c-Ha-ras gene.

Long-term outcome of urinary function after extended lymphadenectomy in patients with distal rectal cancer

AIMS

Extended lymphadenectomy for rectal cancer has been superseded by autonomic nerve-sparing surgery, but it still has historical significance. It is useful to document the long-term outcome of urinary function in cases who had resection of the inferior hypogastric nerve plexus (pelvic nerve plexus).

METHODS

The long-term urinary function following extended lymphadenectomy was studied retrospectively through the medical records of 83 patients who had been followed-up for more than 5 years after surgery.

RESULTS

Forty-four per cent of the male patients and 17% of the female patients had to perform clean intermittent self-catheterization (CIC) for more than 1 year; these rates were almost the same at 3 years after the procedure. Urinary incontinence was reported in 34% of the male patients and 45% of the female patients. Complicated cystitis (eight patients), complicated pyelonephritis (two patients), bladder stones (five patients) that required surgical treatment, and chronic renal failure (two patients) were considered as adverse outcomes of extended surgery. In particular, one case needed to undergo urinary diversion.

CONCLUSIONS

A surprisingly large proportion of patients suffered various urinary tract problems due to extended lymphadenectomy. The findings demonstrate the importance of selection of well-balanced operations that can encompass both radicality and quality of life. The extent of resection should be decided by the extent of the cancer and routine excision of the inferior hypogastric nerve plexus should not be performed.