PubMed · 7607902
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B Wüthrich. 1995. [Ambulatory oral provocation testing].. https://pubmed.ncbi.nlm.nih.gov/7607902/
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The synthesis, in vitro activities, and pharmacokinetics of a series of azepanone-based inhibitors of the cysteine protease cathepsin K (EC 3.4.22.38) are described. These compounds show improved configurational stability of the C-4 diastereomeric center relative to the previously published five- and six-membered ring ketone-based inhibitor series. Studies in this series have led to the identification of 20, a potent, selective inhibitor of human cathepsin K (K(i) = 0.16 nM) as well as 24, a potent inhibitor of both human (K(i) = 0.0048 nM) and rat (K(i,app) = 4.8 nM) cathepsin K. Small-molecule X-ray crystallographic analysis of 20 established the C-4 S stereochemistry as being critical for potent inhibition and that unbound 20 adopted the expected equatorial conformation for the C-4 substituent. Molecular modeling studies predicted the higher energy axial orientation at C-4 of 20 when bound within the active site of cathepsin K, a feature subsequently confirmed by X-ray crystallography. Pharmacokinetic studies in the rat show 20 to be 42% orally bioavailable. Comparison of the transport of the cyclic and acyclic analogues through CaCo-2 cells suggests that oral bioavailability of the acyclic derivatives is limited by a P-glycoprotein-mediated efflux mechanism. It is concluded that the introduction of a conformational constraint has served the dual purpose of increasing inhibitor potency by locking in a bioactive conformation as well as locking out available conformations which may serve as substrates for enzyme systems that limit oral bioavailability.
Although the minimal dose of 17beta-estradiol in hormone replacement regimens was originally considered to be 2 mg/day, it is now increasingly accepted that a lower dose of 1 mg/day is effective in protecting women from the detrimental effects of the menopause. A 1-year, multicentre, double-blind, randomised study was conducted in 214 healthy postmenopausal women in order to assess the effect of 17beta-estradiol (1 mg/day) continuously combined with dydrogesterone (5, 10 or 20 mg/day) in preventing bone loss. Bone mineral density (BMD) was evaluable in 177 women who completed the study. In all women, a statistically significant increase from baseline in lumbar vertebrae (L2-L4) BMD was seen after 6 months ( + 2.4%; p < 0.01); this increase was somewhat greater after 12 months ( + 3.6%; p < 0.01). Similar effects were seen in the hip. After 6 months, BMD in the femoral neck, Ward's triangle and trochanter had increased by 0.20% (not significant [n.s.]), 0.32% (n.s.) and 1.08% (p < 0.01), respectively, compared with baseline. Greater increases were again seen after 12 months ( + 1.16%, + 1.62% and + 2.83%, respectively), all of which were statistically significant (p < 0.01) compared with baseline. The change in BMD from baseline did not differ significantly between the three dydrogesterone dosages for either L2-L4 or hip. All dosages were well-tolerated and amenorrhoea was achieved in over 70%. In conclusion, 17beta-estradiol (1 mg/day) continuously combined with dydrogesterone (5, 10 or 20 mg/day) results in a significant increase in lumbar vertebrae and hip BMD in postmenopausal women. The lower dose of oestrogen and the avoidance of cyclical bleeding make this a particularly suitable regimen for the prevention and treatment of osteoporosis in older women.
BACKGROUND: Recent reports and a previous randomized trial conducted at the authors' institution suggested that a lower risk subset of children with febrile neutropenia under chemotherapy might benefit of an oral antibiotic outpatient approach. METHODS: The objective of this study was to test the efficacy of oral ciprofloxacin in the treatment of lower risk febrile neutropenia (LRFN) in children treated for malignant diseases. From November 1998 to December 1999, 93 episodes of LRFN in 87 children (median age, 5.5 years; range, 0.9-15.8 years) were included in a prospective randomized controlled single institution trial. Inclusion criteria included fever (> 38 degrees C), severe neutropenia (absolute neutrophil count, < 500/mm(3)), and lower risk features (e.g., absence of severe comorbidity factors, good clinical condition, negative blood cultures, control of local infection, prediction of a period of neutropenia less than 10 days after admission, and compliant parents). After 24 hours of a single intravenous ceftriaxone (100 mg/kg) plus amikacin (15 mg/kg) and completed risk assessment workup, patients were discharged and randomly allocated to two groups. Group A (48 episodes) received ciprofloxacin 20 mg/kg/day orally (p.o.) every 12 hours for 6 days. Group B (45 episodes) received intravenous ceftriaxone plus amikacin for 2 days more followed by cefixime (8 mg/kg/day p.o.) every 24 hours for 4 additional days. Failure was defined as the need of a second hospitalization during the same episode. RESULTS: Most of the patients (59% in Group A and 52% in Group B) were treated for malignant solid tumors. Fifteen (31%) children in Group A and 15 (33%) in Group B presented with fever of unknown origin (P value was not significant). No significant differences were found in sites of initial infection between both groups. Overall results in this study were excellent. Only one patient with respiratory failure was detected in Group B, who did well with secondary treatment. CONCLUSIONS: In febrile neutropenic children after anticancer therapy and lower risk features, oral ciprofloxacin for 6 days after 24 hours of intravenous ceftraxione plus amikacin appears to be as efficacious as intravenous ceftriaxone plus amikacin for 2 days more followed by cefixime for 4 additional days. These results contribute to strengthen the concept of LRFN.