Triangle Singularity as the Origin of the a_{1}(1420)

The COMPASS Collaboration experiment recently discovered a new isovector resonancelike signal with axial-vector quantum numbers, the a_{1}(1420), decaying to f_{0}(980)π. With a mass too close to and a width smaller than the axial-vector ground state a_{1}(1260), it was immediately interpreted as a new light exotic meson, similar to the X, Y, Z states in the hidden-charm sector. We show that a resonancelike signal fully matching the experimental data is produced by the decay of the a_{1}(1260) resonance into K^{*}(→Kπ)K[over ¯] and subsequent rescattering through a triangle singularity into the coupled f_{0}(980)π channel. The amplitude for this process is calculated using a new approach based on dispersion relations. The triangle-singularity model is fitted to the partial-wave data of the COMPASS experiment. Despite having fewer parameters, this fit shows a slightly better quality than the one using a resonance hypothesis and thus eliminates the need for an additional resonance in order to describe the data. We thereby demonstrate for the first time in the light-meson sector that a resonancelike structure in the experimental data can be described by rescattering through a triangle singularity, providing evidence for a genuine three-body effect.

First Measurement of Transverse-Spin-Dependent Azimuthal Asymmetries in the Drell-Yan Process

The first measurement of transverse-spin-dependent azimuthal asymmetries in the pion-induced Drell-Yan (DY) process is reported. We use the CERN SPS 190  GeV/c π^{-} beam and a transversely polarized ammonia target. Three azimuthal asymmetries giving access to different transverse-momentum-dependent (TMD) parton distribution functions (PDFs) are extracted using dimuon events with invariant mass between 4.3  GeV/c^{2} and 8.5  GeV/c^{2}. Within the experimental uncertainties, the observed sign of the Sivers asymmetry is found to be consistent with the fundamental prediction of quantum chromodynamics (QCD) that the Sivers TMD PDFs extracted from DY have a sign opposite to the one extracted from semi-inclusive deep-inelastic scattering (SIDIS) data. We present two other asymmetries originating from the pion Boer-Mulders TMD PDFs convoluted with either the nucleon transversity or pretzelosity TMD PDFs. A recent COMPASS SIDIS measurement was obtained at a hard scale comparable to that of these DY results. This opens the way for possible tests of fundamental QCD universality predictions.

Observation of a New Narrow Axial-Vector Meson a1(1420)

The COMPASS Collaboration at CERN has measured diffractive dissociation of 190  GeV/c pions into the π(-)π(-)π(+) final state using a stationary hydrogen target. A partial-wave analysis (PWA) was performed in bins of 3π mass and four-momentum transfer using the isobar model and the so far largest PWA model consisting of 88 waves. A narrow peak is observed in the f0(980)π channel with spin, parity and C-parity quantum numbers J(PC)=1(++). We present a resonance-model study of a subset of the spin-density matrix selecting 3π states with J(PC)=2(++) and 4(++) decaying into ρ(770)π and with J(PC)=1(++) decaying into f0(980)π. We identify a new a1 meson with mass (1414(-13)(+15))  MeV/c2 and width (153(-23)(+8))  MeV/c2. Within the final states investigated in our analysis, we observe the new a1(1420) decaying only into f0(980)π, suggesting its exotic nature.

Measurement of the charged-pion polarizability

The COMPASS collaboration at CERN has investigated pion Compton scattering, π(-)γ→π(-)γ, at center-of-mass energy below 3.5 pion masses. The process is embedded in the reaction π(-)Ni→π(-)γNi, which is initiated by 190 GeV pions impinging on a nickel target. The exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, Q(2)<0.0015  (GeV/c)(2). From a sample of 63,000 events, the pion electric polarizability is determined to be α(π)=(2.0±0.6(stat)±0.7(syst))×10(-4)  fm(3) under the assumption α(π)=-β(π), which relates the electric and magnetic dipole polarizabilities. It is the most precise measurement of this fundamental low-energy parameter of strong interaction that has been addressed since long by various methods with conflicting outcomes. While this result is in tension with previous dedicated measurements, it is found in agreement with the expectation from chiral perturbation theory. An additional measurement replacing pions by muons, for which the cross-section behavior is unambiguously known, was performed for an independent estimate of the systematic uncertainty.

First measurement of chiral dynamics in π- γ → π- π- π+

The COMPASS Collaboration at CERN has investigated the π- γ → π- π- π+ reaction at center-of-momentum energy below five pion masses, sqrt[s]<5m(π), embedded in the Primakoff reaction of 190 GeV pions impinging on a lead target. Exchange of quasireal photons is selected by isolating the sharp Coulomb peak observed at smallest momentum transfers, t'<0.001  GeV2/c2. Using partial-wave analysis techniques, the scattering intensity of Coulomb production described in terms of chiral dynamics and its dependence on the 3π-invariant mass m(3π)=sqrt[s] were extracted. The absolute cross section was determined in seven bins of sqrt[s] with an overall precision of 20%. At leading order, the result is found to be in good agreement with the prediction of chiral perturbation theory over the whole energy range investigated.

50 FIRST EQUINE CLONE BORN IN ARGENTINA BY SOMATIC CELL NUCLEAR TRANSFER FROM A POLO ARGENTINO MARE

Births of the first cloned equids were reported in 2003 (Woods et al. 2003 Science 301(5636), 1063; Galli et al. 2003 Nature 424 (6949), 635) but no equine clones have been reported in Latin America. The aim of this work was to inform the birth of the first equine clone in Argentina as a result of interdisciplinary teamwork. Equine oocytes were obtained from slaughterhouse ovaries and were transported at 38°C for 15 h in TCM-199 buffered with 20 mM HEPES and supplemented with 1 mM glutamine, 0.19 mM sodium pyruvate, 2 μg mL–1 LH, 5 μg mL–1 FSH, 100 ng mL–1 EGF, 100 ng mL–1 IGF-I, and 10% FCS. After 16 to 18 h of maturation, oocytes were denuded and enucleated. Frozen–thawed somatic cells from 1 of 2 aged (23 and 20 years old) Polo Argentino breed donor mares were inserted into the perivitelline space of each enucleated oocyte and fusion was induced. Activation was performed by exposure to Ionomycin (5 μM) for 4 min, followed by 4 h culture in a combination of 6-DMAP and cycloheximide in SOFaas culture media (Choi et al. 2001 Reproduction 122, 177–183). Embryos were cultured in 50 μL SOFm droplets for 7 to 8 days and then were transferred non-surgically to anovulatory recipient mares treated with 1.5 mg oestrogen, followed by long acting progesterone (BioRelease P4 300 LA, BET Pharm, KY). The production rates of the first cell line were: fusion 301/553 (54.4%), cleavage 163/218 (53.4%), blastocysts produced 20/163 (12.2%), blastocysts transferred 18/20 (90%), pregnancies 1/18 (5.5%) and no foal born. The production rates of the second cell line were: fusion 252/553 (45.6%), cleavage 55/252 (21.8%), blastocysts produced 8/55 (14.5%), blastocysts transferred 7/8 (87.5%), pregnancies 4/7 (57%) and 1 filly was born. DNA microsatellite analysis confirmed that the filly was a clone from the original donor cell line. The filly, born naturally on Day 329 of gestation, suffered premature placental separation and weighed 12 kg. Despite the intensive care provided, the filly’s respiratory, nervous, and cardiovascular functions deteriorated rapidly and she died 14 h postpartum. Fetal membranes weighed 5.7 kg (47.5% of the filly’s weight) and showed marked oedema of the chorioalantois and umbilical cord (which also showed a torsion of 9 twists). Histopathologically, the chorioalantois showed scant and poorly developed villi and also connective tissue oedema. Death could have been due to marked immaturity, as a consequence of placental insufficiency and umbilical cord torsion.

Observation of a J(PC)=1-+ exotic resonance in diffractive dissociation of 190 GeV/c π- into π- π- π+

The COMPASS experiment at the CERN SPS has studied the diffractive dissociation of negative pions into the π- π- π+ final state using a 190  GeV/c pion beam hitting a lead target. A partial wave analysis has been performed on a sample of 420,000 events taken at values of the squared 4-momentum transfer t' between 0.1 and 1  GeV2/c2. The well-known resonances a1(1260), a2(1320), and π2(1670) are clearly observed. In addition, the data show a significant natural-parity exchange production of a resonance with spin-exotic quantum numbers J(PC)=1-+ at 1.66  GeV/c2 decaying to ρπ. The resonant nature of this wave is evident from the mass-dependent phase differences to the J(PC)=2-+ and 1++ waves. From a mass-dependent fit a resonance mass of (1660±10(-64)(+0))  MeV/c2 and a width of (269±21(-64)(+42))  MeV/c2 are deduced, with an intensity of (1.7±0.2)% of the total intensity.

129 IN VITRO PRODUCTION OF EQUINE EMBRYOS FROM YOUNG AND OLD MARES BY INTRACYTOPLASMIC SPERM INJECTION

High merit mares obtain their utmost productive value at the same time their reproductive soundness diminishes. The aim of our study was to compare the developmental competence of equine oocytes from young and old mares after intracytoplasmic sperm injection (ICSI) and in vitro culture. Ovaries from young and old mares were obtained from a pool of slaughterhouse animals that have been previously selected by overall good body condition, reproductive status, and age. Young mares were 3 to 8 years old, and old mares were more than 15 years old. The age of all mares was determined by teeth observation and reproductive status by ultrasonography. Oocytes were obtained from ovaries 1 h postmortem by individual dissection of follicles between 10 and 25 mm and scraping of the follicle wall with a bone curette. Recovered oocytes were matured in vitro for 24–30 h, and all oocytes with an intact cytoplasm and a visible polar body were subject to ICSI and cultured for 7.5 days in SOFm. The maturation rate, cleavage, and embryo development rate and mean number of blastomeres at 7.5 days of culture were compared between oocytes and embryos from young and old mares. Maturation, cleavage, and developmental rates were analyzed by Chi Square and Fisher exact test, whereas the mean number of blastomeres at 7.5 days of culture was compared by one way ANOVA and t-test. A total number of 54 oocytes from young mares and 37 oocytes from old mares were obtained. There were no significant differences between the maturation, cleavage, or embryo development rates between young (79.63, 56.41, and 18.18%) and old (91.89, 63.33, and 15.79%) mares. In addition, the mean number of cells on embryos from each group did not differ significantly (57.75 v. 81; young v. old). Our preliminary results show that similar in vitro rates are achieved when oocytes from young or old mares are matured and fertilized in vitro by ICSI. This does not correlate with the reproductive senescence in old mares and the result obtained with other reproductive techniques. Further studies will determine if pregnancies are equally achieved using in vitro produced embryos from both age groups.

[Treatment with enoxaparin adapted to the fertility programs in women with recurrent abortion and thrombophilia]

Acquired and inherited thrombophilia are associated with recurrent pregnancy loss (RPL). Antithrombotic therapy could restore hemostatic balance and improve early placentation and gestational outcome. We evaluated the efficacy of enoxaparin adapted to the fertility program for prevention of pregnancy loss in 35 women (W) with early RPL and thrombophilia. Previous to the diagnosis of thrombophilia, they had had a total of 105 gestations of which 89 (85%) ended in early pregnancy loss. After diagnosis of thrombophilia, 35 subsequent pregnancies were treated with enoxaparin. In 5 cases assisted reproductive techniques were necessary to achieve pregnancy due to couple infertility. In 17 W who had had at least one preclinical pregnancy loss, enoxaparin (20 mg/d/s.c.) was started previous to conception and adapted to the fertility program. All the women continued with the gestational regime. Eighteen W with only clinical pregnancy loss started enoxaparin (20 mg twice per day s.c.) after biochemical pregnancy diagnosis. During gestations heparin dose was adjusted with anti Xa test, maintaining a range between 0.3 at 0.6 u/ml. With antithrombotic therapy, 30/35 (85%) of the pregnancies ended in live birth versus 16/105 (15%) of the pregnancies without treatment (p < 0.001). These results suggest that enoxaparin adapted to the fertility program can be effective in the prevention of preclinical and clinical abortion in women with thrombophilia.

Atypical androgen receptor in the human melanoma cell line IIB-MEL-J

To evaluate the presence of androgen receptors in the human melanoma cell line IIB-MEL-J, a Scatchard plot analysis was performed. Cells in culture revealed a single binding component with an apparent dissociation constant (KD) at 37 degrees C of 11 nM and a binding capacity of 326 fmol/mg protein when measured with [3H]-R1881. Competition analysis revealed an atypical relaxation of specificity, since not only androgen (testosterone, dihydrotestosterone [DHT], R1881) and antiandrogen (hydroxy-flutamide [OH-FLU]) competed for [3H]-R1881 binding, but also estradiol, progesterone, and cortisol at 500-fold excess concentration. Binding of [3H]-estradiol and [3H]-R5020 in the absence of unlabeled DHT were completely suppressed in its presence. Immunohistochemistry of androgen receptor with a monoclonal antibody showed that nuclei were vigorously stained. Different doses of flutamide (FLU) and OH-FLU tested on cultured IIB-MEL-J cells in the presence of serum inhibited significantly cell proliferation in a dose-dependent manner. When cells were incubated with 10 nM DHT and 1% charcoal-adsorbed serum, a significant stimulation of growth that was observed was inhibited by 4 microM OH-FLU. DHT stimulation was completely reversed by the antiestrogen tamoxifen. In addition, male nude mice transplanted with IIB-MEL-J tumor were treated with FLU when tumors were palpable. FLU was effective in diminishing tumor growth and increasing survival rate of the animals. As a conclusion, the presence of functional androgen receptors in these cells has been demonstrated by growth inhibition in vitro and in vivo with antiandrogens, and their atypical nature is suggested by binding cross-reactivity and competition studies.

Effects of an eicosapentaenoic and docosahexaenoic acid concentrate on a human lung carcinoma grown in nude mice

The effects of the n-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), on the growth of a human lung mucoepidermoid carcinoma (HLMC) in athymic mice were studied. The mice were divided into three groups which were given either a control chow diet (C), a chow diet supplemented with EPA/DHA (P) (25 or 50 mg of free n-3 fatty acids/g of pellet/day), or chow diet supplemented with palmitic acid (S) (isocaloric with P). Two independent experimental schedules were followed: i) host mice bearing either tumors that were allowed to reach 4000 mm3, or only 35 mm3, were fed C, P or S for 21 or 41 days; ii) animals were fed C, P and S for 9 days before tumor implant and were maintained on these diets throughout tumor growth. Food consumption, mouse weight and liver/body weight ratio showed no significant differences between supplemented diets and chow. Tumor growth was markedly inhibited (45%) in both experiments by the EPA/DHA supplemented diet. In Experiment 2, only 60% of mice fed diet P had tumors. The fatty acid composition of neutral and polar lipids of host liver and tumor reflected the dietary intake of n-3 fatty acids; the content of arachidonic acid was reduced by 50%, and EPA/DHA was increased 3- to 5-fold. Tumor prostaglandin E2 levels were reduced 7.4-fold in the P group. The reduced PGE2 content may be a factor in tumor growth inhibition.

Description of a new human breast cancer cell line, IIB-BR-G, established from a primary undifferentiated tumor

The establishment of a new human breast cancer cell line (IIB-BR-G) was successful after a previous growth of the cells isolated from a breast primary tumor in a female nude mouse. The IIB-BR-G cell line and the primary tumor do not express estrogen or progesterone receptors. Vimentin and keratin expression were found in the cell line and in the nude mouse tumor. This cell line displays high morphological heterogeneity with atypical multinucleated megacells, and it is capable of anchorage-independent growth and tumor formation in nude mice. The cytogenetic analysis confirmed its human origin and revealed multiple marker chromosomes and extensive chromosomal alterations including rearrangements, gains, losses, isochromosomes, and double minutes (DMs).

Calomys laucha (Rodentia, Cricetidae): growth and breeding in laboratory conditions

The husbandry and breeding of Calomys laucha (Rodentia, Cricetidae) in captivity are described. Growth curves based on body weight and length showed statistical differences between sexes after 45 days, males being heavier than females. The overall reproductive efficiency was 53.4% but birth rate was depressed during winter. Gestation length was 21 +/- 1 days and females exhibited postpartum oestrus with a 3-7 day implantation delay (51%). Litter size was 5.3 +/- 1.1 (n = 34). Pup survival at weaning was 84.9%. Mean life span in laboratory conditions was 13.5 months and a cumulative mortality of 90% was reached at 27-28 months of age.

Tumor lipids and liver lipid metabolism in the model human lung carcinoma/nude mice

Tumor lipids were studied in the experimental model Human Lung Carcinoma/nude mice as well as the effect of this human neoplasm on the host liver lipid metabolism. Fatty acid profiles from tumoral lipids revealed the loss of specificity for fatty acid composition in triglycerides. Host liver fatty acid composition and cholesterol metabolism were affected by the implanted human lung tissue. A noticeable increase ratio between saturated/unsaturated fatty acids was observed in host liver fatty acid phospholipids (1.17 +/- 0.17) in comparison to control liver (0.84 +/- 0.04). Cholesterol synthesis was assessed "in vivo" by means of [14C]acetate incorporation. The specific radioactivity of [14C] cholesterol was increased by a factor of about 6 in host liver as compared with control liver. This observation along with the marked decrease in the cholesterol content of host liver and the hypocholesterolemia detected in the host mice led us to suggest an increase in the liver cholesterol catabolism promoted by the presence of the tumor.

Mortality induced by adoptive immunity in Junin virus-infected athymic mice

The effect of normal or sensitized spleen cell transfer from syngeneic euthymic mice to Junin virus-infected suckling athymic mice was studied. Transfer was performed 1 or 7 days after infection. In both cases, an acute lethal disease developed 6-11 days after transfer. The mortality reached 100% in all infected groups receiving normal or sensitized splenocytes, while it was negligible for different control groups of athymic mice. Transfer of normal or sensitized splenocytes was unable to significantly modify brain viral titers, as compared with infected nontransferred athymic mice killed after a 25-day observation period. Brain lesions were demonstrated in about half of the infected athymic mice transferred with sensitized splenocytes and in all euthymic infected mice. These results show that splenocyte transfer from immunocompetent donors is able to change the normal course of persistent Junin virus infection in nude mice to a lethal acute disease, thus pointing to a main role for T cells in its pathogenesis.