Search

We report measurements of the exclusive cross section for e(+)e(-)-->D(0)D(-)pi(+) over the center-of-mass energy range 4.0 GeV to 5.0 GeV with initial-state radiation and the first observation of the decay psi(4415)-->D(0)D(-)pi(+). From a study of the resonant substructure in psi(4415) decay we conclude that the psi(4415)-->D(0)D(-)pi(+) decay is dominated by psi(4415)-->DD(2)(*)(2460). We obtain B(psi(4415)-->D(0)D(-)pi(nonresonant)(+))/B(psi(4415)-->DD(2)(*)(2460)-->D(0)D(-)pi(+))<0.22 at 90% C.L. The analysis is based on a data sample collected with the Belle detector with an integrated luminosity of 673 fb(-1).

We present a search for the rare decays B --> h(*)nunu[over ], where h(*) stands for a light meson. A data sample of 535 x 10{6} BB[over ] pairs collected with the Belle detector at the KEKB e{+}e{-} collider is used. Signal candidates are required to have an accompanying B meson fully reconstructed in a hadronic mode and signal side particles consistent with a single h(*) meson. No significant signal is observed and we set upper limits on the branching fractions at 90% confidence level. The limits on B{0} --> K{*0}nunu[over ] and B{+} --> K{+}nunu[over ] decays are more stringent than the previous constraints, while the first searches for B{0} --> K{0}nunu[over ], pi{0}nunu[over ], rho{0}nunu[over ], varphinunu[over ] and B{+} --> K{*+}nunu[over ], rho{+}nunu[over ] are reported.

We report the first search for CP-violating decays of the Upsilon(4S) using a data sample that contains 535 x 10(6) Upsilon(4S) mesons with the Belle detector at the KEKB asymmetric-energy e(+)e(-) collider. A partial reconstruction technique is employed to enhance the signal sensitivity. No significant signals were observed. We obtain an upper limit of 4 x 10(-7) at the 90% confidence level for the branching fractions of the CP violating modes, Upsilon(4S)-->B(0)B(0)-->J/psiK(S)(0)+J/psi(eta(c))K(S)(0). Extrapolating the result, we find that an observation with 5sigma significance is expected with a 30 ab(-1) data sample, which is within the reach of a future super B factory.

We report a measurement of D0-D(0) mixing parameters in D(0) --> K(s)(0) pi(+) pi(-) decays using a time-dependent Dalitz-plot analysis. We first assume CP conservation and subsequently allow for CP violation. The results are based on 540 fb(-1) of data accumulated with the Belle detector at the KEKB e(+)e(-) collider. Assuming negligible CP violation, we measure the mixing parameters x = (0.80 +/- 0.29(-0.07-0.14)(+0.09+0.10))% and y = (0.33+/-0.24(-0.12-0.08)(+0.08+0.06))%, where the errors are statistical, experimental systematic, and systematic due to the Dalitz decay model, respectively. Allowing for CP violation, we obtain the CP-violating parameters |q / p| = 0.86(-0.29-0.03)(+0.30+0.06) +/- 0.08 and arg(q/p) = (-14(-18-3-4)(+16+5+2)) degrees .

As it is quick and easy to prepare sperm with SpermPrep column, this method was assessed in the andrology laboratory for IUI preparations, as an alternative to Percoll, since Percoll is not available in market. This paper evaluates sperm prepared by SpermPrep method and compares them to those prepared by MiniPercoll for matched asthenozoospermic specimens. Spermatozoa prepared with MiniPercoll were of significantly higher quality, when compared with those prepared by SpermPrep, in terms of computer-assisted sperm motion parameters, recovery of motile fraction, morphology, hypoosmotic swelling and nuclear stability as assessed by sodium dodecyl sulphate exposure. SpermPrep did not appear to be equivalent to MiniPercoll and therefore could not be widely applied to asthenozoospermic specimens. It may be used on an individual basis, depending on the initial semen sample. Although other density gradient methods such as colloidal silica particles coated with silane appear to be equivalent to Percoll, they need to be critically evaluated with respect to their batches or different sources of vendors and be compared to Percoll as a standard method.

The widespread use of hormonal contraceptives for a prolonged time in women during the child-bearing period necessitates that appropriate precautions be taken to ensure safety for the patient as well as for her progeny. Hormonal administration during or prior to pregnancy may be potentially teratogenic. Although there have been many reports during the last decade, it has been very difficult to document conclusively such a relationship. Over-all, it seems that hormonal use prior to pregnancy does not lead to an increase in the frequency of chromosomal aberrations or of congenital malformations. The use of certain hormones during pregnancy, on the other hand, may lead to an increase in the incidence of congenital malformations, probably in the genetically predisposed fetus. In view of this concept hormonal contraceptives should not be used to treat threatened abortion, and their use as a pregnancy test should be abandoned. Since the question of the safety of the inadvertent administration of pills during early pregnancy has not been resolved, the mother should be informed of the potential risks.

The activity of delta 5-3 beta hydroxysteroid dehydrogenase (delta 5-3 beta HSD) in pre-implantation mouse embryos was inhibited following their prior incubation with partially purified sheep ovarian follicular fluid peptide (OFFP). OFFP, 5 microliter, injected into the uterine lumen of day 4 pregnant mice impaired the ensuing implantation of embryos. Our observations suggest that OFFP may inhibit steroid metabolizing activity in pre-implantation embryos and thereby interfere with the process of implantation.

In the present study, augmentation of contractile responses to acetylcholine, potassium chloride and caffeine by prostaglandin F2 alpha on frog rectus abdominis muscle is documented. The PG-induced responses to ACh was restricted to brief exposure of the tissue to PG. Prolonged exposure resulted in disappearance of the enhancing effect and depression of ACh responses. The augmentation of ACh response was unaltered in presence of physostigmine and the pA2-value of d-tubocurarine was not changed by PGF2 alpha ruling out the involvement of a cholinergic mechanism. In potassium depolarized muscle, PGF2 alpha abolished the contractile response to caffeine, indicating an action at the trigger calcium site. PGF2 alpha also permitted reactivation contracture during repolarization.

The effect of guanethidine on the alpha-adrenoceptor blocking potency of phentolamine was studied using the rabbit aortic strip and rat vas deferens. The agonists used were noradrenaline (in presence of DOCA and cocaine which block uptake mechanisms) and xylometazoline (which is not taken up by uptake mechanisms). Guanethidine augmented the responses to noradrenaline and xylometazoline and increased the pA2 value of phentolamine against both agonists. Increased affinity of alpha-receptors may be partly responsible for the guanethidine-induced supersensitivity to alpha-adrenoceptor agonists.

Human chorionic gonadotrophin (hCG)-like activity has been reported in mouse and rabbit blastocysts. The presence of this hCG-like activity seems to be essential for nidation of the pre-implantation embryo. Binding sites for hCG were localised on day 4 mouse embryos by immunohistochemical techniques. Presence of hCG-like activity was confirmed by cytotoxicity test. The number of implantation sites was significantly reduced on day 8 of pregnancy. Prior treatment to day 4 mouse embryos with hCG antiserum, for 1 h in utero or in vitro and their subsequent transfer to uteri of synchronised pseudopregnant mice resulted in impaired implantation of embryos, compared to controls treated with normal rabbit serum (NRS). These results suggest that hCG-like activity present on the pre-implantation embryo may have a significant role in implantation of the embryo.

Antiacetylcholine activity some beta-adrenoceptor-blocking drugs was investigated using isolated guinea pig cremaster muscle and frog fectus abdominis muscle. On the cremaster muscle, the antagonism to acetylcholine was non competitive in K0 1313, (+/-)-INPEA and (--)-INPEA, competitive in (+)-INPEA and functional in practolol; All three INPEA isomers, practolol and propranolol behaved as noncompetitive antagonists of acetylcholine on frog rectus muscle. Caffeine-induced contractions of this muscle were partially inhibited by propranolol but not by the other drugs. It is suggested that the beta-adrenoceptor-blocking drugs produce their antiacetylcholine action by interaction with sites on the muscle which are different from the cholinceptor, and which vary between compounds and species.

In anococcygeus muscle and vas deferens preparations of rat, guanidinomethyl-2-benzo-(1,4)-dioxane (guanoxan) potentiated responses to norepinephrine (NF) in concentrations which exerted a neurone blocking effect. The potentiation was significantly reduced in reserpinized preparations and was abolished in the presence of nialamide. The possible mechanisms of potentiation have been discussed. Higher concentrations of guanoxan produced concentration-related contractions. The contractions were significantly less in reserpinized preparations. Phentolamine both prevented and reversed the contractions while methysergide was ineffective in this respect. Thus the effect of guanoxan appears to be mediated through the activation of alpha-receptors by the released NE.