Search for D0-D(-)0 mixing and a measurement of the doubly Cabibbo-suppressed decay rate in D0-->Kpi decays

We present results of a search for D0-D(-)0 mixing and a measurement of R(D), the ratio of doubly Cabibbo-suppressed decays to Cabibbo-favored decays, using D0-->K+pi- decays from 57.1 fb(-1) of data collected near sqrt[s]=10.6 GeV with the BABAR detector at the PEP-II collider. At the 95% confidence level, allowing for CP violation, we find the mixing parameters x('2)<0.0022 and -0.056<y(')<0.039, and the mixing rate R(M)<0.16%. In the limit of no mixing, R(D)=[0.357+/-0.022(stat)+/-0.027(syst)]% and the CP-violating asymmetry A(D)=0.095+/-0.061(stat)+/-0.083(syst).

Rates, polarizations, and asymmetries in charmless vector-vector B meson decays

With a sample of approximately 89 x 10(6) B(-)B pairs collected with the BABAR detector, we perform a search for B meson decays into pairs of charmless vector mesons (phi, rho, and K*). We measure the branching fractions, determine the degree of longitudinal polarization, and search for CP violation asymmetries in the processes B+-->phiK(*+), B0-->phiK(*0), B+-->rho(0)K(*+), and B+-->rho(0)rho(+). We also set an upper limit on the branching fraction for the decay B0-->rho(0)rho(0).

Measurements of CP-violating asymmetries and branching fractions in B meson decays to eta'K

We present measurements of the branching fractions of the decays B+-->eta'K+ and B0-->eta'K0. For B0-->eta(')K(0)(S) we also measure the time-dependent CP-violation parameters S eta'(K(0)(S)) and C eta'(K(0)(S)), and for B+-->eta'K+ the time-integrated charge asymmetry A(ch). The data sample corresponds to 88.9 x 10(6) BB pairs produced by e(+)e(-) annihilation at the Upsilon(4S). The results are B(B+-->eta'K+)=(76.9+/-3.5+/-4.4) x 10(-6), B(B0-->eta'K0)=(60.6+/-5.6+/-4.6) x 10(-6), S eta'(K(0)(S))=0.02+/-0.34+/-0.03, C eta'(K(0)(S))=0.10+/-0.22+/-0.04, and A(ch)=0.037+/-0.045+/-0.011.

Measurement of time-dependent CP asymmetries and the CP-odd fraction in the decay B0-->D(*+)D(*-)

We present a measurement of time-dependent CP asymmetries and an updated determination of the CP-odd fraction in the decay B0-->D(*+)D(*-) using a data sample of 88x10(6)BB pairs collected by the BABAR detector at the PEP-II B Factory at SLAC. We determine the CP-odd fraction to be 0.063+/-0.055(stat)+/-0.009(syst). The time-dependent CP asymmetry parameters Im(lambda(+)) and /lambda(+)/ are determined to be 0.05+/-0.29(stat)+/-0.10(syst) and 0.75+/-0.19(stat)+/-0.02(syst), respectively. The standard model predicts these parameters to be -sin(2beta and 1, respectively, in the absence of penguin diagram contributions.

Limits on D0-macro D0 mixing and CP violation from the ratio of lifetimes for decay to K-pi+, K-K+, and pi- pi+

We present a measurement of D0-macro D0 mixing parameters using the ratios of lifetimes extracted from samples of D0 mesons decaying to K-pi(+), K-K+, and pi(-)pi(+). Using 91 fb(-1) of data collected by the BABAR detector at the PEP-II asymmetric-energy B Factory, we obtain a value Y=[0.8+/-0.4(stat.)(+0.5)(-0.4)(syst.)]%, which, in the limit of CP conservation, corresponds to the mixing parameter y=Delta Gamma/2 Gamma. Using the difference in lifetimes of D0 and macro D0 mesons, we obtain the CP-violation parameter Delta Y=[-0.8+/-0.6(stat.)+/-0.2(syst.)]%.

Rare B decays into states containing a J/psi meson and a meson with s(-)s quark content

We report a study of the B meson decays, B+ --> J/psiphiK+, B0 --> J/psiphiK(0)(S), B0 --> J/psiphi, B0 --> J/psieta, and B0 --> J/psieta' using 56 x 10(6) B(-)B events collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II e(+)e(-) asymmetric-energy storage ring. We measure the branching fractions B(B+ --> J/psiphiK+)=(4.4+/-1.4(stat)+/-0.5(syst))x 10(-5) and B(B0 --> J/psiphiK(0)(S))=(5.1+/-1.9(stat)+/-0.5(syst))x 10(-5), and set upper limits at 90% confidence level for the branching fractions B(B0 --> J/psiphi)<9.2 x 10(-6), B(B0 --> J/psieta)<2.7 x 10(-5), and B(B0 --> J/psieta')<6.3 x 10(-5).

Study of time-dependent CP asymmetry in neutral B decays to J/psi pi0

We present the first study of the time-dependent CP-violating asymmetry in B0-->J/psi pi(0) decays using e(+)e(-) annihilation data collected with the BABAR detector at the Upsilon(4S) resonance during the years 1999-2002 at the PEP-II asymmetric-energy B Factory at SLAC. Using approximately 88 x 10(6) BB; pairs, our results for the coefficients of the cosine and sine terms of the CP asymmetry are C(J/psi pi(0))=0.38+/-0.41(stat)+/-0.09(syst) and S(J/psi pi(0))=0.05+/-0.49(stat)+/-0.16(syst).

Measurements of the branching fractions and bounds on the charge asymmetries of charmless three-body charged B decays

We present measurements of branching fractions and charge asymmetries for charmless B-meson decays to three-body final states of charged pions and kaons. The analysis uses 81.8 fb(-1) of data collected at the Upsilon(4S) resonance with the BABAR detector at the SLAC PEP-II asymmetric B Factory. We measure the branching fractions B(B+-->pi(+)pi(-)pi(+))=(10.9+/-3.3+/-1.6)x10(-6), B(B+-->K+pi(-)pi(+))=(59.1+/-3.8+/-3.2)x10(-6), and B(B+-->K+K-K+)=(29.6+/-2.1+/-1.6)x10(-6) and provide 90% C.L. upper limits for other decays. We observe no charge asymmetries for these modes.

Observation of the decay B+/--->pi+/-pi0, study of B+/--->K+/-pi0, and search for B0-->pi0pi0

We present results for the branching fractions and charge asymmetries in B+/--->h(+/-)pi(0) (where h(+/-)=pi(+/-),K+/-) and a search for the decay B0-->pi(0)pi(0) using a sample of approximately 88 x 10(6) BBmacr; pairs collected by the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We measure B(B+/--->pi(+/-)pi(0))=(5.5(+1.0)(-0.9)+/-0.6)x10(-6), where the first error is statistical and the second is systematic. The B+/--->pi(+/-)pi(0) signal has a significance of 7.7sigma including systematic uncertainties. We simultaneously measure the K+/-pi(0) branching fraction to be B(B+/--->K+/-pi(0))=(12.8(+1.2)(-1.1)+/-1.0)x10(-6). The charge asymmetries are Api(+/-)(pi(0))=-0.03(+0.18)(-0.17)+/-0.02 and AK+/-(pi(0))=-0.09+/-0.09+/-0.01. We place a 90% confidence-level upper limit on the branching fraction B(B0-->pi(0)pi(0)) of 3.6 x 10(-6).

Observation of a narrow meson state decaying to D(+)(s)pi(0) at a mass of 2.32 GeV/c(2)

We have observed a narrow state near 2.32 GeV/c(2) in the inclusive D(+)(s)pi(0) invariant mass distribution from e(+)e(-) annihilation data at energies near 10.6 GeV. The observed width is consistent with the experimental resolution. The small intrinsic width and the quantum numbers of the final state indicate that the decay violates isospin conservation. The state has natural spin-parity and the low mass suggests a J(P)=0(+) assignment. The data sample corresponds to an integrated luminosity of 91 fb(-1) recorded by the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)e(-) storage ring.

Evidence for B+-->J/psip(-)Lambda; and search for B0-->J/psip(-)p

We have performed a search for the decays B+-->J/psip(-)Lambda; and search for B0-->J/psip(-)p. in a data set of (88.9+/-1.0) x 10(6) Upsilon(4S) decays collected by the BABAR experiment at the PEP-II e(+)e(-) storage ring at the Stanford Linear Accelerator Center. Four charged B candidates have been observed with an expected background of 0.21+/-0.14 events. The corresponding branching fraction is (12(+9)(-6)) x 10(-6), where statistical and systematic uncertainties have been combined. The result can be interpreted as a 90% confidence level (C.L.) upper limit of 26 x 10(-6). We also find one B0 candidate, with an expected background of 0.64+/-0.17 events, implying a 90% C.L. upper limit of 1.9 x 10(-6).

Measurement of the branching fraction, and bounds on the CP-violating asymmetries, of neutral B decays to D*+/- D-/+

We present measurements of the branching fraction and CP-violating asymmetries for neutral B decays to D(*+/-)D-/+. The measurement uses a data sample of approximately 88x10(6) Upsilon(4S)-->BBmacr; decays collected with the BABAR detector at the SLAC PEP-II asymmetric-energy e(+)-e(-) collider. By fully reconstructing the D(*+/-)D-/+ decay products, we measure the branching fraction to be (8.8+/-1.0+/-1.3)x10(-4) and the time-integrated CP-violating asymmetry between the rates to D(*-)D+ and D(*+)D- to be A=-0.03+/-0.11+/-0.05. We also measure the time-dependent CP-violating asymmetry parameters to be S(-+)=-0.24+/-0.69+/-0.12, C(-+)=-0.22+/-0.37+/-0.10 for B-->D(*-)D+ and S(+-)=-0.82+/-0.75+/-0.14, C(+-)=-0.47+/-0.40+/-0.12 for B-->D(*+)D-. In each case, the first error is statistical and the second error is systematic.

Measurement of the Cabibbo-Kobayashi-Maskawa matrix element V(ub) with B-->rhoenu decays

We present a measurement of the branching fraction for the rare decays B-->rhoenu and extract a value for the magnitude of V(ub), one of the smallest elements of the Cabibbo-Kobayashi-Maskawa quark-mixing matrix. The results are given for five different calculations of form factors used to para-metrize the hadronic current in semileptonic decays. Using a sample of 55 x 10(6) BB meson pairs recorded with the BABAR detector at the PEP-II e(+)e(-) storage ring, we obtain B(B0-->rho(-)e(+)nu)=(3.29+/-0.42+/-0.47+/-0.55) x 10(-4) and |V(ub)|=(3.64+/-0.22+/-0.25(+0.39)(-0.56)) x 10(-3), where the uncertainties are statistical, systematic, and theoretical, respectively.

Study of the rare decays B0-->D((*)+)(s)pi(-) and B0-->D((*)-)(s)K+

We report evidence for the decays B0-->D(+)(s)pi(-) and B0-->D(-)(s)K+ and the results of a search for B0-->D(*+)(s)pi(-) and B0-->D(*-)(s)K+ in a sample of 84 x 10(6) upsilon(4S) decays into BB pairs collected with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage ring. We measure the branching fractions B(B0-->D(+)(s)pi(-))=[3.2+/-0.9(stat)+/-1.0(syst)] x 10(-5) and B(B0-->D(-)(s)K+)=[3.2+/-1.0(stat)+/-1.0(syst)] x 10(-5). We also set 90% C.L. limits B(B0-->D(*+)(s)pi(-))<4.1 x 10(-5) and B(B0-->D(*-)(s)K+)<2.5 x 10(-5).

Measurement of the B0-->J/psipi+pi- branching fraction

We present a measurement of the branching fraction for the decay of the neutral B meson into the final state J/psipi(+)pi(-). The data set contains approximately 56 x 10(6) BB pairs produced at the Upsilon(4S) resonance and recorded with the BABAR detector at the PEP-II asymmetric-energy e(+)e(-) storage ring. The result of this analysis is B(B0-->J/psipi(+)pi(-))=(4.6+/-0.7+/-0.6) x 10(-5), where the first error is statistical and the second is systematic. In addition, we measure B(B0-->J/psirho(0))=(1.6+/-0.6+/-0.4) x 10(-5).

Measurements of branching fractions and CP-violating asymmetries in B0-->pi+pi-, K+pi-, K+K- decays

We present measurements of branching fractions and CP-violating asymmetries for two-body neutral B meson decays to charged pions and kaons based on a sample of about 88x10(6) Upsilon(4S)-->BB decays. From a time-independent fit we measure the charge-averaged branching fractions B(B0-->pi+pi-)=(4.7+/-0.6+/-0.2)x10(-6), B(B0-->K+pi-)=(17.9+/-0.9+/-0.7)x10(-6), and the direct CP-violating charge asymmetry A(Kpi)=-0.102+/-0.050+/-0.016 [-0.188,-0.016], where the ranges in square brackets indicate the 90% confidence intervals. From a time-dependent fit we measure the B0-->pi+pi- CP-violating parameters S(pipi)=0.02+/-0.34+/-0.05 [-0.54,+0.58] and C(pipi)=-0.30+/-0.25+/-0.04 [-0.72,+0.12].

Observation of double radiative capture on pionic hydrogen

We report the first observation of double radiative capture on pionic hydrogen. The experiment was conducted at the TRIUMF cyclotron using the RMC spectrometer and detected gamma-ray coincidences following pi(-) stops in liquid hydrogen. We found the branching ratio for double radiative capture to be [3.05+/-0.27(stat)+/-0.31(syst)]x10(-5). The measured branching ratio and angle-energy distributions support the theoretical prediction of a dominant contribution from the pipi-->gammagamma annihilation mechanism.

Measurement of the CP asymmetry amplitude sin2beta with B0 mesons

We present results on time-dependent CP asymmetries in neutral B decays to several CP eigenstates. The measurements use a data sample of about 88 x 10(6) Upsilon(4S)-->B(-)B decays collected between 1999 and 2002 with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. We study events in which one neutral B meson is fully reconstructed in a final state containing a charmonium meson and the other B meson is determined to be either a B(0) or B(-0) from its decay products. The amplitude of the CP asymmetry, which in the standard model is proportional to sin2beta, is derived from the decay-time distributions in such events. We measure sin2beta=0.741+/-0.067(stat)+/-0.034(syst) and |lambda|=0.948+/-0.051(stat)+/-0.030(syst). The magnitude of lambda is consistent with unity, in agreement with the standard model expectation of no direct CP violation in these modes.

Measurement of the branching fraction and CP content for the decay B0-->D(*+)D(*-)

We report a measurement of the branching fraction of the decay B0-->D(*+)D(*-) and of the CP-odd component of its final state using the BABAR detector. With data corresponding to an integrated luminosity of 20.4 fb (-1) collected at the Upsilon(4S) resonance during 1999-2000, we have reconstructed 38 candidate signal events in the mode B0-->D(*+)D(*-) with an estimated background of 6.2+/-0.5 events. From these events, we determine the branching fraction to be B(B0-->D(*+)D(*-))=[8.3+/-1.6(stat)+/-1.2(syst)]x10(-4). The measured CP-odd fraction of the final state is 0.22+/-0.18(stat)+/-0.03(syst).

Measurement of the B(0) lifetime with partially reconstructed B(0)-->D(-)l(+)nu(l) decays

The B(0) lifetime was measured with a sample of 23 million BB pairs collected by the BABAR detector at the PEP-II e(+)e(-) storage ring during 1999 and 2000. Events from the semileptonic decay B(0)-->D(*-)l(+)nu(l) have been selected with a partial reconstruction method in which only the charged lepton and the slow pi from the D*--->D(0)pi(-) decay are reconstructed. The result is tau(B(0)) = 1.529+/-0.012(stat)+/-0.029(syst) ps.

Search for the rare decays B-->Kl(+)l(-) and B-->K(*)l(+)l(-)

We present results from a search for the flavor-changing neutral current decays B-->Kl(+)l(-) and B-->K(*)l(+)l(-), where l(+)l(-) is either an e(+)e(-) or mu(+)mu(-) pair. The data sample comprises 22.7 x 10(6) Upsilon(4S)-->B(-)B decays collected with the BABAR detector at the PEP-II B Factory. We obtain the 90% C.L. upper limits B(B-->Kl(+)l(-))<0.51 x 10(-6) and B(B-->K(*)l(+)l(-))<3.1 x 10(-6), close to standard model predictions for these branching fractions. We have also obtained limits on the lepton-family-violating decays B-->Ke+/-mu(-/+) and B-->K(*)e(+/-)mu(-/+).

Search for T and CP violation in B0-B-0 mixing with inclusive dilepton events

We report the results of a search for T and CP violation in B0-B-0 mixing using an inclusive dilepton sample collected by the BABAR experiment at the PEP-II B Factory. The asymmetry between l+l+ and l-l- events allows us to compare the probabilities for B-0-->B0 and B0-->B-0 oscillations and thus probe T and CP invariance. Using a sample of 23 x 10(6) BB- pairs, we measure a same-sign dilepton asymmetry of A(T/CP) = [0.5+/-1.2(stat)+/-1.4(syst)]%. For the modulus of the ratio of complex mixing parameters p and q, we obtain q/p = 0.998+/-0.006(stat)+/-0.007(syst).

Measurement of B0-B-0 flavor oscillations in hadronic B0 decays

Flavor oscillations of neutral B mesons have been studied in e+e- annihilation data collected with the BABAR detector at center-of-mass energies near the upsilon(4S) resonance. The data sample used for this purpose consists of events in which one B0 meson is reconstructed in a hadronic decay mode, while the flavor of the recoiling B0 is determined with a tagging algorithm that exploits the correlation between the flavor of the heavy quark and the charges of its decay products. From the time development of the observed mixed and unmixed final states, we determine the B0-B-0 oscillation frequency deltamd to be 0.516+/-0.016(stat)+/-0.010(syst) ps-1.

Measurement of the B0-B-0 oscillation frequency with inclusive dilepton events

The B0-B-0 oscillation frequency has been measured with a sample of 23 x 10(6) BB- pairs collected with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. In this sample, we select events in which both B mesons decay semileptonically and use the charge of the leptons to identify the flavor of each B meson. A simultaneous fit to the decay time difference distributions for opposite- and same-sign dilepton events gives deltamd = 0.493+/-0.012(stat)+/-0.009(syst) ps-1.

Measurement of B --> K*gamma branching fractions and charge asymmetries

The branching fractions of the exclusive decays B0-->K(*0)gamma and B+-->K(*+)gamma are measured from a sample of (22.74+/-0.36)x10(6) BB decays collected with the BABAR detector at the PEP-II asymmetric e(+)e(-) collider. We find B (B0-->K(*0)gamma) = [4.23+/-0.40(stat)+/-0.22(syst)]x10(-5), B(B+-->K(*+)gamma) = [3.83+/-0.62(stat)+/-0.22(syst)]x10(-5) and constrain the CP-violating charge asymmetry to be -0.170<A(CP)(B-->K(*)gamma)<0.082 at 90% C.L.

Pharmacodynamics of trovafloxacin and levofloxacin against Bacteroides fragilis in an in vitro pharmacodynamic model

An in vitro pharmacodynamic investigation was conducted to explore whether the area under the concentration time curve from 0 to 24 h (AUC(0-24))/MIC ratio could predict fluoroquinolone performance against Bacteroides fragilis. An in vitro model was used to generate kill curves for trovafloxacin (TVA) and levofloxacin (LVX) at AUC(0-24)/MIC ratios of 1 to 406 against three strains of B. fragilis (ATCC 25285, ATCC 23745, and clinical isolate M97-117). TVA and LVX were bolused prior to the start of experiments to achieve the corresponding AUC(0-24)/MIC ratio. Experiments were performed in duplicate over 24 h and in an anaerobic environment. Analyses of antimicrobial performance were conducted by comparing the rates of bacterial kill (K) using nonlinear regression analysis with 95% confidence intervals. Statistical significance was defined as a lack of overlap in the 95% confidence limits generated from the slope of each kill curve. For both TVA and LVX, K was maximized once an AUC(0-24)/MIC ratio of > or =40 was achieved and was not further increased despite a 10-fold increase in AUC(0-24)/MIC from approximately 40 to 400 against all three strains of B. fragilis. No significant differences were found in K between AUC(0-24)/MIC ratios of approximately 40 to 200. In experiments where AUC(0-24)/MIC ratios that were > or = 5 and < or = 44 were conducted, 64% demonstrated regrowth at 24 h. Resistant strains were selected in 50% of those experiments, demonstrating regrowth, which resulted in increased MICs of two- to 16-fold for both TVA and LVX. Regrowth did not occur, nor were resistant strains selected in any studies with an AUC/MIC that was > 44. Our findings suggest that fluoroquinolones provide antibacterial effects against B. fragilis in a concentration-independent manner associated with an AUC(0-24)/MIC ratio of > or =40. Also, the potential for the selection of resistant strains of B. fragilis may increase with an AUC(0-24)/MIC ratio of < or =44.

Search for the decay B0-->gammagamma

We present a limit on the branching fraction for the decay B0-->gammagamma using data collected at the Upsilon(4S) resonance with the BABAR detector at the PEP-II asymmetric energy e+e- collider. Based on the observation of one event in the signal region, out of a sample of 21.3x10(6) e+e--->Upsilon(4S)-->BB decays, we establish an upper limit on the branching fraction of B(B0-->gammagamma)<1.7x10(-6) at the 90% confidence level. This result substantially improves upon existing limits.

Measurement of the B--> J/psiK*(892) decay amplitudes

We present a measurement of the decay amplitudes in B-->J/psiK*(892) channels using 20.7 fb(-1) of data collected at the Upsilon(4S) resonance with the BABAR detector at PEP-II. We measure a P-wave fraction R(perpendicular) = (16.0 +/- 3.2 +/- 1.4)% and a longitudinal polarization fraction (59.7 +/- 2.8 +/- 2.4)%. The measurement of a relative phase that is neither 0 nor pi, phi = 2.50 +/- 0.20 +/-0.08 radians, favors a departure from the factorization hypothesis. Although the decay B-->/psiK(pi) proceeds mainly via K*(892), there is also evidence for K2*(1430) and K(pi) S-wave contributions.

Measurements of the branching fractions of exclusive charmless B meson decays with eta(') or omega mesons

We present the results of searches for B decays to charmless two-body final states containing eta(') or omega mesons, based on 20.7 fb(-1) of data collected with the BABAR detector. We find the branching fractions Beta(B(+)-->eta(')K(+)) = (70+/-8+/-5) x 10(-6), Beta(B(0)-->eta(')K(0)) = (42(+13)(-11) +/- 4) x 10(-6), and Beta(B(+)-->omega pi(+)) = (6.6(+2.1)(-1.8) +/- 0.7) x 10(-6), where the first error quoted is statistical and the second is systematic. We give measurements of four additional modes for which the 90% confidence level upper limits are Beta(B(+)-->eta(')pi(+)) < 12 x 10(-6), Beta(B(+)-->omega K(+)) < 4 x 10(-6), Beta(B(0)-->omega K(0)) < 13 x 10(-6), and Beta(B(0)-->omega pi(0)) < 3 x 10(-6).

Prostanoid receptors: ontogeny and implications in vascular physiology

Prostanoids exert significant effects on circulatory beds. They play a role in the response of the vasculature to adjustments in perfusion pressure and oxygen and carbon dioxide tension, and they mediate the actions of numerous factors. The role of prostanoids in governing circulation of the perinate is suggested to surpass that in the adult. Prostanoids are abundantly generated in the perinate. They have been implicated in autoregulation of blood flow as studied in brain and eyes. Prostaglandins are also dominant regulators of ductus arteriosus tone. The effects of these autacoids are mediated through specific G protein-coupled receptors. In addition to the pharmacological characterization of the prostanoid receptors, important advances in understanding the biology of these receptors have been made in the last decade. Their cloning and the development of animals with disrupted genes of these receptors have been very informative. The involvement of prostanoid receptors in the developing subject, especially on brain and ocular vasculature and on ductus arteriosus, has also begun to be investigated; the expression of these receptors changes with development. Some but not all of the ontogenic changes in these receptors are attributed to homologous regulation. Interestingly, in the process of elucidating their effects, functional perinuclear prostaglandin E2 receptors have been uncovered. This article reviews prostanoid receptors and addresses implications on the developing subject with attention to vascular physiology.

Measurement of J/psi production in continuum e(+)e(-) annihilations near square root of s = 10.6 GeV

The production of J/psi mesons in continuum e(+)e(-) annihilations has been studied with the BABAR detector at energies near the Upsilon(4S) resonance. The mesons are distinguished from J/psi production in B decays through their center-of-mass momentum and energy. We measure the cross section e(+)e(-)-->J/psi X to be 2.52+/-0.21+/-0.21 pb. We set a 90% C.L. upper limit on the branching fraction for direct Upsilon(4S)-->J/psi X decays at 4.7 x 10(-4).

Observation of CP violation in the B(0) meson system

We present an updated measurement of time-dependent CP-violating asymmetries in neutral B decays with the BABAR detector at the PEP-II asymmetric B Factory at SLAC. This result uses an additional sample of Upsilon(4S) decays collected in 2001, bringing the data available to 32 x 10(6) BB macro pairs. We select events in which one neutral B meson is fully reconstructed in a final state containing charmonium and the flavor of the other neutral B meson is determined from its decay products. The amplitude of the CP-violating asymmetry, which in the standard model is proportional to sin2 beta, is derived from the decay time distributions in such events. The result sin2 beta = 0.59+/-0.14(stat)+/-0.05(syst) establishes CP violation in the B(0) meson system. We also determine absolute value of lambda = 0.93+/-0.09(stat)+/-0.03(syst), consistent with no direct CP violation.

Fluoroquinolone resistance in anaerobic bacteria following exposure to levofloxacin, trovafloxacin, and sparfloxacin in an in vitro pharmacodynamic model

This investigation explored pharmacodynamic characteristics of fluoroquinolones against Bacteroides thetaiotamicron and the potential for development of resistance. An in vitro model was used to generate kill curves with three fluoroquinolones at various area under the concentration-time curve (AUC)/MIC ratios. Concentration-independent killing was observed. Increases in MICs were noted following exposure to fluoroquinolones at AUC/MIC ratios of 6 to 14.

Molecular analysis reveals somatically mutated and unmutated clonal and oligoclonal B cells in T-cell-rich B-cell lymphoma

This paper describes the immunohistology and molecular genetics of 18 cases of T-cell-rich B-cell lymphoma (TCRBL). In all cases, the large B cells stained strongly for CD20, with more variable expression of CD79a, and were negative for CD30 and CD15. The majority of T cells were predominantly positive for TIA-1 and negative for CD57; a large population of histiocytes was present in all cases. Epstein-Barr virus (EBV)-coded RNA (EBER) was found in B blasts from four cases and in one case was present among the background lymphoid cells. IgH PCR products were generated in 16/18 cases and revealed clonal, oligoclonal and polyclonal PCR products in 12, two and two cases, respectively. In addition, TCRG clonal gene rearrangements were identified in two cases. TCRB gene rearrangements were polyclonal. Sequence analysis of seven cases with clonal/oligoclonal IgH gene rearrangements revealed functional sequences with predominant V(H)3 gene usage associated with various D genes and J(H)4 or J(H)6 gene segments. Four cases displayed varying degrees of replacement and silent mutations (1.8-21%), with one case exhibiting intraclonal heterogeneity; the distribution of mutations was indicative of antigen selection in three cases. The remaining three cases, including two cases with functional oligoclonal IgH rearrangements, harboured unmutated V region genes. The EBV-positive cases were associated with clonal, oligoclonal and polyclonal PCR products and with mutated and germline clonal sequences. These data indicate that TCRBL may be a heterogeneous entity associated with clonal and oligoclonal B cells derived from both germinal centre and naïve B cells.

The human prostanoid DP receptor stimulates mucin secretion in LS174T cells

This study demonstrates the localization of the prostaglandin (PG)D(2) receptor (DP) within the mucous-secreting globlet cells of the human colon by in situ hybridization, which suggests a role for DP in mucous secretion. Selective high affinity ligands were used, therefore, to evaluate DP regulation of mucous secretion in LS174T human colonic adenocarcinoma cells. The expression of hDP in LS174T cells was confirmed at the mRNA level by reverse transcriptase-polymerase chain reaction, and at the protein level by radioligand binding assays and signal transduction (cyclic AMP accumulation) assays. PGD(2) and the highly selective DP-specific agonist L-644,698 ((4-(3-(3-(3-hydroxyoctyl)-4-oxo-2-thiazolidinyl) propyl) benzoic acid) (racemate)), but not PGE(2) competed for [(3)H]-PGD(2)-specific binding to LS174T cell membranes (K:(i) values of 0.4 nM and 7 nM, respectively). The DP-specific agonists PGD(2), PGJ(2), BW245C (5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropylhydantoin)), and L-644,698 showed similar potencies in stimulating cyclic AMP accumulation (EC(50) values: 45 - 90 nM) and demonstrated the expected rank order of potency. PGE(2) also elicited cyclic AMP production in this cell line (EC(50) value: 162 nM). The activation of cyclic AMP production by PGD(2) and L-644,698, but not PGE(2), was inhibited by the selective DP antagonist BW A868C. Thus, PGD(2) and L-644,698 act through hDP in LS174T cells. PGD(2), L-644,698 and PGE(2) (an established mucin secretagogue) potently stimulated mucin secretion in LS174T cells in a concentration-dependent manner (EC(50)<50 nM). However, BW A868C effectively antagonized only the mucin secretion mediated by PGD(2) and L-644,698 and not PGE(2). These data support a role for the DP receptor in the regulation of mucous secretion.

Application of fluoroquinolone pharmacodynamics

Pharmacodynamics provides a rational basis for optimizing dosing regimens by describing the relationship between drug, host and antimicrobial effect. The successful identification of meaningful pharmacodynamic outcome parameters can, therefore, greatly assist clinicians in making objective prescribing decisions rather than relying on static in vitro MIC data. While pharmacodynamic outcome parameters have been proposed for select antimicrobial agents, their clinical application remains to be defined fully. Quinolone antibiotics are generally considered to have concentration-dependent bactericidal activity and peak/MIC and AUC/MIC ratios have been identified as possible pharmacodynamic predictors of clinical and microbiological outcome as well as the development of bacterial resistance. Investigators have suggested that AUC/MIC ratios of 100-125 or peak/MIC ratios of >10 are required to predict clinical and microbiological success and to limit the development of bacterial resistance. These conclusions are derived primarily from studies of Gram-negative bacteria, and recent data suggest that these ratios may not be applicable for Streptococcus pneumoniae, where an AUC/MIC ratio of <40 appears to be a more accurate predictor. There is considerable variation in pharmacodynamic calculations and outcome parameters appear to be quinolone- and pathogen-specific. Additional prospective clinical research is needed to characterize quinolone pharmacodynamic parameters and answer unresolved questions regarding optimal pharmacodynamic outcome predictors for Gram-positive bacteria, anaerobes and atypical respiratory pathogens.

Risk factors for Hodgkin's disease by Epstein-Barr virus (EBV) status: prior infection by EBV and other agents

A UK population-based case-control study of Hodgkin's disease (HD) in young adults (16-24 years) included 118 cases and 237 controls matched on year of birth, gender and county of residence. The majority (103) of the cases were classified by Epstein-Barr virus (EBV) status (EBV present in Reed-Stenberg cells), with 19 being EBV-positive. Analyses using conditional logistic regression are presented of subject reports of prior infectious disease (infectious mononucleosis (IM), chicken pox, measles, mumps, pertussis and rubella). In these analyses HD cases are compared with matched controls, EBV-positive cases and EBV-negative cases are compared separately with their controls and formal tests of differences of association by EBV status are applied. A prior history of IM was positively associated with HD (odds ratio (OR) = 2.43, 95% confidence interval (CI) = 1.10-5.33) and with EBV-positive HD (OR = 9.16, 95% CI = 1.07-78.31) and the difference between EBV-positive and EBV-negative HD was statistically significant (P = 0.013). The remaining infectious illnesses (combined) were negatively associated with HD, EBV-positive HD and EBV-negative HD (in the total series, for > or =2 episodes compared with < or =1, OR = 0.45, 95% CI = 0.25-0.83). These results support previous evidence that early exposure to infection protects against HD and that IM increases subsequent risk; the comparisons of EBV-positive and EBV-negative HD are new and generate hypotheses for further study.

Frequent T and B cell oligoclones in histologically and immunophenotypically characterized angioimmunoblastic lymphadenopathy

The identification of clonal rearrangements of T cell receptor (TCR) genes is central to the diagnosis of T cell lymphomas. However, in angioimmunoblastic lymphadenopathy (AILD), first described as a nonneoplastic proliferation associated with immunodeficiency, the heterogeneity of TCR and IgH gene rearrangements suggest that some cases may harbor multiple lymphoid clones. In this study we have isolated DNA from archival paraffin biopsy material from 22 cases of AILD identified on the basis of classical histological and immunohistochemical features with the aim of establishing the occurrence of clones and oligoclones, the frequency of TCR and immunoglobulin heavy chain (IgH) variable (v) gene use, and the relationship of these findings to the presence of Epstein-Barr virus. DNA extracted from the biopsies was amplified using the polymerase chain reaction (PCR) and sequenced to detect functional and nonfunctional gene rearrangements. Epstein-Barr virus-encoded short RNA species (EBERs) were detected using in situ hybridization combined with immunochemistry to identify the phenotype of the Epstein-Barr virus-infected cells. Fifty-seven clonal products were found in 20/22 patients: TCRgamma clonal products were identified in 16/22, TCRbeta clonal products in 16/22 and IgH clonal products in 6/22 cases. Oligoclonal PCR products were seen for TCR in 3/22 and for IgH in 3/22 cases. In one biopsy PCR products from all reactions were polyclonal. Sequence analysis revealed functional TCRgamma, TCRbeta, and IgH sequences in 6/12, 9/11, and 8/8 cases, respectively. Functional TCR and/or IgH oligoclones were detected in 6/20 (30%) cases. In addition, nonfunctional TCR and IgH sequences were found in 11 cases. EBERs were identified in 18/20 cases varying from occasional to 25 to 30% nuclei staining and were associated with both T and B cells, although the majority were of indeterminate phenotype. The presence of EBERs was not associated with all clonal IgH gene rearrangements but was associated with B cell oligoclones. Patterns of gene recombinations indicated that the majority of TCRgamma recombinations used GV1 and GJ1S3/2S3 genes. Six out of eleven cases used TCR BV4S1 or BV2S1 genes associated with various BJ and BD1/2 genes. No common IgH gene usage was identified, but 8 clones had varying degrees of replacement and silent mutations (0.6-10.1%), consistent with B cell clones having undergone somatic mutation in the germinal center, and 3 clones harbored unmutated V genes, consistent with naive B cells. Our data do not support the concept of AILD as a clearly defined peripheral T cell lymphoma (PTCL). Rather, they suggest that AILD as defined by histology and immunohistochemistry is either a heterogeneous entity or represents a lymphoproliferation associated with immunodeficiency in which clonal T cell or B cell proliferation may occur.

Enteropathy-type intestinal T-cell lymphoma: clinical features and treatment of 31 patients in a single center

PURPOSE

We report the clinical features and treatment of 31 patients with a diagnosis of enteropathy-type intestinal T-cell lymphoma treated at the Wessex Regional Medical Oncology Unit in Southampton between 1979 and 1996 (23 men, eight women).

PATIENTS AND METHODS

Patients were identified from our lymphoma database. Details of history, physical examination, staging investigations, treatment, and outcome were taken from patient records.

RESULTS

Twelve patients (35%) had a documented clinical history of adult-onset celiac disease, and a further three had histologic features consistent with celiac disease in resected areas of the small bowel not infiltrated with lymphoma. After diagnosis, 24 (77%) of the 31 patients were treated with chemotherapy; the remaining seven had surgical treatment alone. More than half were unable to complete their planned chemotherapy courses, often because of poor nutritional status; 12 patients required enteral or parenteral feeding. A response to initial chemotherapy was observed in 14 patients (complete response, n = 10; partial response, n = 4). Observed complications of treatment were gastrointestinal bleeding, small-bowel perforation, and the development of enterocolic fistulae. Relapses occurred 1 to 60 months from diagnosis in 79% of those who responded to initial therapy. Of the total 31 patients, 26 (84%) have died, all from progressive disease or from complications of the disease and/or its treatment. The actuarial 1- and 5-year survival rates are 38.7% and 19.7%, respectively, with 1- and 5-year failure-free survival rates of 19.4% and 3.2%, respectively.

CONCLUSION

The prognosis for these patients is poor. This, in part, reflects late diagnosis and poor performance status at the time of presentation. The role of salvage treatments and high-dose chemotherapy at relapse is not clear. However, it is encouraging that there are five long-term survivors in our patient population.

Decreased in vitro fluoroquinolone concentrations after admixture with an enteral feeding formulation

BACKGROUND

The purpose of this study was to determine if mixing of fluoroquinolones with a common enteral feeding formulation, Ensure (Ross Products Division, Abbott Laboratories, Columbus, OH), would alter the measured in vitro quinolone concentrations over a 24-hour period.

METHODS

Tablets of ciprofloxacin (500 mg), levofloxacin (500 mg), and ofloxacin (300 mg) were crushed and mixed with 240 mL of Ensure, water and calcium chloride (500 mg/L), water and magnesium chloride (200 mg/L), water and calcium chloride and magnesium chloride, and water alone. Fluoroquinolone concentrations of the mixtures were measured, via high-performance liquid chromatography, at baseline and serially over 24 hours. Experiments were performed in duplicate, at three temperatures (5 degrees C, 25 degrees C, and 37 degrees C).

RESULTS

Average decreases of 82.5% +/- 1.5% for ciprofloxacin, 61.3% +/- 5.2% for levofloxacin, and 45.7% +/- 10.1% for ofloxacin (mean +/- 95% CI) were observed in vitro for Ensure over the two experimental sets at baseline. Serial analysis revealed no further significant change in any of the quinolone concentrations over the remaining 24-hour period. No significant decrease was noted with the quinolones when mixed in water and calcium, water and magnesium, water and calcium and magnesium, or water alone. This phenomenon appears to be unaffected by time and temperature.

CONCLUSIONS

These data suggest there is an immediate and significant loss of fluoroquinolone when mixed with Ensure. An explanation for the loss of fluoroquinolone remains unclear.

Fluoroquinolone resistance in Bacteroides fragilis following sparfloxacin exposure

In vitro pharmacodynamic studies investigating the antimicrobial properties of five fluoroquinolones, (trovafloxacin, sparfloxacin, clinafloxacin, levofloxacin, and ciprofloxacin) against Bacteroides fragilis ATCC 23745 were conducted. The times required to reduce the viable counts by 3 log units were as follows: clinafloxacin, 2.9 h; levofloxacin, 4.6 h; trovafloxacin, 6 h; and sparfloxacin, 10 h. Exposure to ciprofloxacin did not achieve a 3-log decrease in viable counts. The susceptibility of B. fragilis was determined both prior to exposure and following 24 h of exposure to each of the five fluoroquinolones tested. The MICs of clinafloxacin, levofloxacin, trovafloxacin, sparfloxacin, ciprofloxacin, metronidazole, cefoxitin, chloramphenicol, and clindamycin were determined by the broth microdilution method. The MICs for B. fragilis preexposure were as follows: clinafloxacin, 0.25 microg/ml; trovafloxacin, 0.5 microg/ml; sparfloxacin, 2 microg /ml; levofloxacin, 2 microg/ml; and ciprofloxacin, 8 microg/ml. Similar pre- and postexposure MICs were obtained for cultures exposed to trovafloxacin, clinafloxacin, levofloxacin, and ciprofloxacin. However, following 24 h of exposure to sparfloxacin, a fluoroquinolone-resistant strain emerged. The MICs for this strain were as follows: clinafloxacin, 1 microg/ml; trovafloxacin, 4 microg/ml; sparfloxacin, 16 microg/ml; levofloxacin, 16 microg/ml; and ciprofloxacin, 32 microg/ml. No changes in the susceptibility of B. fragilis pre- and postexposure to sparfloxacin were noted for metronidazole (MIC, 1 microg/ml), cefoxitin (MIC, 4 microg /ml), chloramphenicol (MIC, 4 microg/ml), and clindamycin (MIC, 0.06 microg/ml). Resistance remained stable as the organism was passaged on antibiotic-free agar for 10 consecutive days. Mutant B. fragilis strains with decreased susceptibility to clinafloxacin, trovafloxacin, sparfloxacin, levofloxacin, and ciprofloxacin were selected on brucella blood agar containing 8x the MIC of levofloxacin at a frequencies of 6.4 x 10(-9), 4x the MICs of trovafloxacin and sparfloxacin at frequencies of 2.2 x 10(-9) and 3. 3 x 10(-10), respectively, and 2x the MIC of clinafloxacin at a frequency of 5.5 x 10(-11); no mutants were selected with ciprofloxacin. The susceptibilities of strains to trovafloxacin, levofloxacin, clinafloxacin, sparfloxacin, and ciprofloxacin before and after exposure to sparfloxacin were modestly affected by the presence of reserpine (20 microg/ml), an inhibitor of antibiotic efflux. The mechanism of fluoroquinolone resistance is being explored, but it is unlikely to be efflux due to a lack of cross-resistance to unrelated antimicrobial agents and to the fact that the MICs for strains before and after exposure to sparfloxacin are minimally affected by reserpine.

Nefazodone and cyclosporine drug-drug interaction

Depression is a significant post-transplant complication often necessitating drug therapy. Many of the newer selective serotonin reuptake inhibitor (SSRI) antidepressants are metabolized by the same cytochrome P450IIIA isoenzyme system that is responsible for the metabolism of cyclosporine, and these agents pose an interactive risk in transplant patients. We have observed nearly a 10-fold increase in whole blood cyclosporine concentrations in a cardiac transplant patient shortly after the addition of nefazodone antidepressant therapy. We suggest there is a clinically significant drug-drug interaction between nefazodone and cyclosporine due to inhibition of cytochrome P-450 IIIA4 isoenzymes by nefazodone.

A novel biological role for prostaglandin D2 is suggested by distribution studies of the rat DP prostanoid receptor

We report the cloning, functional expression and cell-specific localization of the rat homologue of the prostaglandin D2 receptor (DP). In situ hybridization, utilizing multiple digoxigenin-labelled riboprobes and their complementary sense controls, was performed to determine the detailed distribution of DP receptor mRNA in the central nervous system and the gastrointestinal tract. Within the brain, the leptomeninges and choroid plexus expressed DP receptor mRNA. Transcripts detected in the spinal cord were localized to the sensory and motor neurons of the dorsal and ventral horns, respectively, suggesting a role for the DP receptor in the modulation of central nervous system processes, including pain transmission. Within the gastrointestinal tract (stomach, duodenum, ileum and colon) signals were highly localized to the mucous-secreting goblet cells and the columnar epithelium. These findings suggest a novel biological role for prostaglandin D2-mediated activity at the DP receptor, namely mucous secretion. In addition, radioligand binding assays (saturation analyses and equilibrium competition assays) and functional assays (measuring cAMP accumulation) were performed to characterize the recombinant rat DP receptor expressed in human embryonic kidney (HEK) 293(EBNA) cells. A single site of binding (K(D) = 14 nM, Bmax = 115 fmol/mg protein) was measured for prostaglandin D2-specific binding to the rat DP receptor. Prostaglandin D2 proved to be a potent agonist at the rat DP receptor (EC50 = 5 nM). The rank order of efficacy for DP receptor specific agonists [prostaglandin D2 = prostaglandin J2 = BW 245C (5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropylhydantoin)) > L-644,698 ((4-(3-(3-(3-hydroxyoctyl)-4-oxo-2-thiazolidinyl) propyl) benzoic acid) (racemate)] reflected the affinity with which the ligands bound to the receptor.

Implications of vancomycin degradation products on therapeutic drug monitoring in patients with end-stage renal disease

In renally impaired patients, vancomycin concentrations typically are maintained at body temperature for extended periods of time due to the drug's prolonged half-life. Both time and increased temperature potentiate production of vancomycin crystalline degradation products (CDP-1). Commercially available vancomycin assays, such as fluorescence polarization immunoassay (FPI) and radioimmunoassay, cross-react with CDP-1 isomers. Overestimation of vancomycin concentrations by 40-53% due to cross-reactivity of CDP-1 with active factor B vancomycin occurs with FPI. As FPI is the most common method of analyzing serum vancomycin, clinicians must be aware of its potential shortcomings and be prepared to alter vancomycin dosages in renally impaired patients. The possibility of adverse affects due to elevated concentrations of CDP-1 or therapeutic failures due to subtherapeutic levels of factor B vancomycin cannot be excluded.

Bacillus anthracis: medical issues of biologic warfare

Recent world events refocused attention on the possibility of nations engaging in biologic warfare, including an attack with Bacillus anthracis. The single available anthrax vaccine in the United States for human use, formerly known as MDPH-PA, has decreased ability to protect laboratory animals against virulent B. anthracis strains, especially compared with new vaccines being developed. Studies with these vaccines, however, have several shortcomings. The pathogenesis, diagnosis, treatment, and prophylaxis of anthrax are discussed, as well as the implications that an attack with B. anthracis would place on the health care system.

Gram-positive infections: pharmacy issues and strategy for quinupristin/dalfopristin

The development of the first streptogramin antibiotic, quinupristin/dalfopristin represents an attempt to bring new antimicrobial strategies on line to combat the menacing problem of Gram-positive-resistant bacteria. With introduction to the medical center formulary, the pharmacy will need to be aware of several practical issues surrounding the use of quinupristin/dalfopristin. Cost and unit size will be important issues. Initially, this drug will only be available in 500-mg vials which may not always accommodate the suggested dose of 7.5 mg/kg of actual body weight. In addition, the drug can only be reconstituted with D5W or sterile water, and it can not be mixed with normal saline, heparin, or other drugs. Institutions adding this drug to their formularies must address the expected logistical concerns with their medical, nursing, and pharmacy staffs prior to patient usage.