Biomedical subjects

M Dolker

Publications and source records attributed to M Dolker.

4 recordsLinked to original sources

PubMed1999

A randomized controlled trial of four doses of transdermal estradiol for preventing postmenopausal bone loss. Transdermal Estradiol Investigator Group.

OBJECTIVE: To determine the effects of four doses of a 7-day transdermal 17beta-estradiol (E2) delivery system, including 0.025 mg/day, on bone loss in postmenopausal women. METHODS: This was a multicenter, double-masked, randomized, placebo-controlled study of the effects of transdermal E2 at doses of 0.025, 0.05, 0.06, and 0.1 mg/day for the prevention of postmenopausal osteoporosis. Efficacy was evaluated from bone mineral density of lumbar vertebrae L2-L4, radius, proximal femur, and total hip measured with dual-energy x-ray absorptiometry. Serum osteocalcin and urinary pyridinoline and deoxypyridinoline concentrations were measured. RESULTS: At 24 months, E2 doses of 0.025, 0.05, 0.06, and 0.1 mg/day resulted in mean increases in bone mineral density of the lumbar spine of 2.37%, 4.09%, 3.28%, and 4.70%, respectively, and increased bone mineral density of the total hip by 0.26%, 2.85%, 3.05%, and 2.03%, respectively. All increases were statistically significantly greater than placebo, which decreased bone mineral density by 2.49% at the spine and 2.04% at the hip. Consistent and significant improvements in biochemical markers of bone turnover also were noted at various intervals in all treatment groups. The most frequent adverse events were local reactions from the transdermal drug-delivery system, effects of estrogen, and menopausal symptoms. CONCLUSION: Transdermal E2 at doses of 0.025, 0.05, 0.06, and 0.1 mg/day effectively prevented bone loss in postmenopausal women.

Administration, Cutaneous↗

PubMed1999

International clinical experience with a new low-dose, monophasic oral contraceptive containing levonorgestrel 100 microg and ethinyl estradiol 20 microg.

Manufacturers have steadily been decreasing the amounts of estrogen and progestin in oral contraceptives (OCs) in an effort to enhance safety and tolerability while preserving contraceptive efficacy. A new formulation containing 20 microg ethinyl estradiol (EE) and 100 microg levonorgestrel (LNG)--representing the lowest available contraceptive dose of each hormone--has undergone extensive clinical testing in the United States and Germany. A total of 1590 women in 61 centers received 20 microg EE and 100 microg LNG for 6 cycles. Overall, 4 pregnancies possibly related to treatment failure were reported, reflecting an overall Pearl Index (number of pregnancies per 100 woman-years of treatment) of 0.65 and a failure rate of 0.34%. Cycle control was typical of low-dose OC use. Spotting and breakthrough bleeding occurred most commonly during the earlier cycles in each study. Adverse events were typical of those seen with OC use and led to study discontinuation in 6.6% of the women. Intermenstrual bleeding was the cause for early study withdrawal in 2.6% of women. The study results suggest that the combination of 20 microg EE and 100 microg LNG offers the benefits of low hormone content with good contraceptive efficacy, cycle control, and tolerability.

Adult↗

PubMed1989

Ventricular defibrillation using biphasic waveforms: the importance of phasic duration.

Biphasic waveforms can be used to defibrillate the heart with less energy than that used by monophasic waveforms. In 14 anesthetized open chest dogs with large contoured defibrillation electrodes, the effect on defibrillation efficacy of varying the duration of the two phases of biphasic waveforms was studied. All combinations of 0, 1, 3.5, 6 and 8.5 ms duration were used for both the first and the second phase except for the meaningless case in which both durations were 0 ms. The 3.5-2 waveform (3.5 ms first phase and 2 ms second phase) was also tested. All the hearts were defibrillated with less than or equal to 5 joules using any of the 25 waveforms. However, biphasic waveforms with the second phase shorter than or equal to the first had significantly lower defibrillation thresholds than did those with the second phase longer than the first or than did monophasic waveforms of approximately the same total duration. A plot of defibrillation threshold current strength versus second phase duration for all biphasic waveforms with a 3.5 ms first phase did not produce a hyperbolic strength-duration curve as seen with monophasic waveforms. To verify these findings, defibrillation dose-response curves were obtained for the 3.5-2, 6-6 and 3.5-8.5 biphasic waveforms in another six dogs. The 50 and 80% successful voltage doses of the 3.5-8.5 waveforms were significantly higher than those of the other two waveforms, which were not different from one another.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Rapid bolus injection of gadopentetate dimeglumine: absence of side effects in normal volunteers.

The safety and tolerance of gadopentetate dimeglumine 0.1 mmol/kg when injected at a bolus rate (10 ml/15 sec; four times the recommended rate) was studied in 12 normal men between the ages of 20 and 36 years. Each of the subjects received a single injection of either gadopentetate dimeglumine (0.2 ml/kg) or a placebo (normal saline, 0.2 ml/kg), followed by a 7-day washout and a single injection of the alternative treatment (six subjects per sequence). Measurement parameters included blood pressure, pulse rate, ECG, cardiographic rhythm strips, hematology and blood chemistry evaluations, physical examinations, and adverse drug experiences. Variations of greater than or equal to +/- 15 mm Hg in diastolic blood pressure and greater than or equal to +/- 15 beats per min in heart rate were observed in some subjects after injection of either gadopentetate dimeglumine or the placebo, but no clinically significant changes from baseline were observed for any parameter. Post-gadopentetate dimeglumine results were not significantly different statistically from post-placebo results. No adverse experiences were reported for any subject. It is concluded that gadopentetate dimeglumine is safe and well tolerated when administered to normal men at a rapid injection rate of 10 ml/15 sec.

Adult↗