Giant Cross Section for Molecular Ion Formation in Ultracold Rydberg Gases.

We have studied the associative ionization of a Rydberg atom and a ground-state atom in an ultracold Rydberg gas. The measured scattering cross section is 3 orders of magnitude larger than the geometrical size of the produced molecule. This giant enhancement of the reaction kinetics is due to an efficient directed mass transport which is accelerated by the Rydberg electron. We also find that the total inelastic scattering cross section is given by the geometrical size of the Rydberg electron's wave function.

Effect of extended-cycle regimen with an oral contraceptive containing 30 mcg ethinylestradiol and 2 mg dienogest on bleeding patterns, safety, acceptance and contraceptive efficacy.

BACKGROUND: The present study compared the efficacy and safety of a combined oral contraceptive containing 30 mcg ethinylestradiol and 2 mg dienogest (EE/DNG) in conventional and extended-cycle regimen over 1 year of treatment. STUDY DESIGN: In a phase III, randomized, prospective, open, two-arm, multicenter study, 1315 sexually active women (range, 18-40 years) were treated with EE/DNG either conventionally (21/7 days) or according to an extended-cycle regimen (84/7 days). Data were documented on volunteer diaries, and adverse events (AEs) were reported during five visits. RESULTS: In the extended-regimen group, the total number of days with bleeding progressively decreased over time, and overall, the volunteers had fewer numbers of days with bleeding/spotting compared to those treated conventionally. Intracyclic bleeding, on the other hand, was more frequent in the extended-cycle group, although its frequency considerably decreased over time. Both regimens offered reliable contraception, with an unadjusted Pearl Index of 0.489 for the conventional regimen and 0.495 for the extended regimen. The number of AEs was higher in the extended-cycle group, although the group differences tended to decrease over time. CONCLUSIONS: Extended-cycle use of EE/DNG was effective and mostly well tolerated, appearing to be a favorable option for women who need or wish to omit the pill-free interval.

Effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on lipid metabolism during 1 year of conventional or extended-cycle use.

BACKGROUND: The effects of extended regimens of combined oral contraceptives (COC) on lipid parameters are largely unknown. The present study compared the effects of a COC containing 30 mcg ethinyl estradiol and 2 mg dienogest (EE/DNG) in conventional and extended-cycle regimen over 1 year. STUDY DESIGN: Lipid parameters were measured in 59 women treated with EE/DNG either conventionally (21+7 days) or in extended-cycle regimen (84+7 days). Blood samples were taken in a control cycle and at 3 and 12 months of treatment. RESULTS: The mean levels of total cholesterol, HDL cholesterol and HDL(2) cholesterol underwent modest to moderate significant increases over time, while the significant increase in triglycerides and VLDL cholesterol was more pronounced with both regimens. LDL cholesterol decreased slightly in both regimen groups, whereas lipoprotein(a) was transiently decreased at 3 months only in the extended-cycle group. The changes reached a steady-state at latest at 3 months, but did not exceed the given normal ranges for any of the parameters. Notably, except for lipoprotein(a), the changes in mean lipid levels were not significantly different in the conventional and the extended-cycle regimen at 3 or 12 months of treatment. CONCLUSION: Use of EE/DNG in conventional or extended-cycle regimen resulted in comparable changes of lipid parameters.

Effects of conventional or extended-cycle regimen of an oral contraceptive containing 30 mcg ethinylestradiol and 2 mg dienogest on various hemostasis parameters.

BACKGROUND: The study was conducted to investigate the effect of a combined oral contraceptive (COC) containing 30 mcg ethinylestradiol and 2 mg dienogest with two different regimens on various hemostasis variables. STUDY DESIGN: Hemostatic parameters were measured in 59 women treated with a monophasic COC containing 30 mcg ethinylestradiol and 2 mg dienogest (EE/DNG) either conventionally (13 cycles with 21 days of treatment+7 days without hormones) or with an extended-cycle regimen (4 extended cycles with 84 days of continuous administration of EE/DNG, followed by a hormone-free interval of 7 days). Blood samples were taken on Days 21-26 of the preceding control cycle and on Days 19-21 of the 3rd and 13th conventional cycle or on Days 82-84 of the first and fourth extended cycle. RESULTS: After 3 and 12 months, significant increases in fibrinogen (20%), factor VII antigen (50-60%), factor VII activity (45%), activated factor VII (30-45%) and factor VIII activity (10-20%) occurred in both treatment regimens. In both groups, there was a small but significant decrease in the level and activity of antithrombin, a 20-25% decrease in total and free protein S and a 15-20% rise in the level and activity of protein C, but no significant change of the thrombin-antithrombin complex. A significant over-time rise by about 25% of prothrombin fragment 1+2 occurred only in the extended-cycle group, but this effect did not differ significantly from that observed during conventional treatment. Plasminogen was elevated by 50% in both groups, while tissue-plasminogen activator (t-PA) activity rose by 15% in the conventional group and by 25-30% in the extended-cycle group. In both groups, t-PA antigen was reduced by about 30% and plasminogen activator inhibitor-1 by 40-60%. The levels of the plasmin-antiplasmin complex rose by 30-40% and those of D-dimers by 20-55%. The prothrombin time was slightly increased and the activated partial thromboplastin time was slightly decreased. CONCLUSION: In general, these results were in agreement with those observed during treatment with other COCs. The study demonstrated that during conventional and extended-cycle treatment with EE/DNG, a steady-state in the effects on hemostasis variables was reached within 3 months, and that the effects observed after 3 and 12 months of treatment did not substantially differ between conventional and extended-cycle regimen.

Effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on thyroid hormones and androgen parameters: conventional vs. extended-cycle use.

BACKGROUND: This study was conducted to investigate the effects of an oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest on thyroid hormones and androgen parameters. STUDY DESIGN: Thyroid and androgen parameters were measured in 59 women treated with a monophasic combined oral contraceptive containing 30 mcg ethinyl estradiol and 2 mg dienogest (EE/DNG) either conventionally (13 cycles with 21 days of treatment+7 days without hormones) or according to an extended-cycle regimen (four extended cycles with 84 days of continuous administration of EE/DNG, followed by a hormone-free interval of 7 days). Blood samples were taken on Days 21-26 of the preceding control cycle and on Days 19-21 of the 3rd and 13th conventional cycle, or on Days 82-84 of the first and fourth extended cycle. RESULTS: At both time points, the serum concentrations of thyroxine-binding globulin were elevated by about 65% in both treatment regimens. Likewise, both groups showed an increase in total triiodothyronine (T3) and total thyroxine (T4) by 30-40%, and no change in free T4. Until the 12th month of conventional treatment, the level of free T3 remained unchanged but decreased slightly during the extended-cycle regimen. In both groups there was a rise of sex hormone-binding globulin by 210-230% after 3 months and by 220-250% after 12 months. The levels of total testosterone were reduced by about 40% and those of free testosterone by 55-65% after 3 and 12 months. CONCLUSION: The results suggest that, during conventional and extended-cycle treatment with EE/DNG, a steady state in the effects on thyroid hormones and androgen parameters was reached within 3 months and that the changes in the various hormonal parameters did not substantially differ between conventional and extended-cycle regimen.