Bone Marrow Collection: Comparison of Unassisted vs Assisted Bedside Collections by a Laboratory Technologist.

OBJECTIVES: Bone marrow collections are often difficult, and creating quality smears and touch preparations at the bedside can prove challenging. The objective of this study is to compare the quality of bone marrow specimens between unassisted and assisted bone marrow collections by a bone marrow technologist. METHODS: Data for this study were collected from 422 hematopathology reports over 14 months. We recorded the bone marrow quality of the different parts (aspirate smears, touch imprints, core biopsy, and clot/particle sections) as adequate, suboptimal, or inadequate. Student t test statistical analysis was performed between the corresponding parts in the two groups. RESULTS: Our results demonstrate that the quality of assisted bone marrow specimens is significantly better compared with unassisted specimens, particularly for the aspirate smears (P < .0001) and touch imprints (P < .0001). Notably, the quality of aspirate smears was improved, which is important for cytologic evaluation. CONCLUSIONS: We conclude that assistance by a bone marrow technologist resulted in a significant improvement in the quality of bone marrow collection.

Estrogen receptor ligands. II. Discovery of benzoxathiins as potent, selective estrogen receptor alpha modulators.

The discovery and synthesis of dihydrobenzoxathiins as potent, ERalpha subtype selective ligands are described. The most active analogue, 4-D, was found to be 50-fold selective in a competitive binding assay and 100-fold selective in a transactivation assay in HEK-293 cells. The alpha selectivity was postulated to lie in the interaction of the sulfur atom of the benzoxathiin ring with the two discriminating residues in the binding pocket of the receptor isoforms.

A beta-lactamase-dependent Gal4-estrogen receptor beta transactivation assay for the ultra-high throughput screening of estrogen receptor beta agonists in a 3456-well format.

Estrogen action is mediated via two estrogen receptor (ER) subtypes, ERalpha and ERbeta. Selective ER modulators with balanced high affinity for ERalpha and ERbeta have been developed as therapeutics for the treatment of a variety of diseases, including hormone-responsive breast cancer and osteoporosis. Recent data based primarily on the evaluation of ER-knockout mice have revealed that ERalpha and ERbeta may regulate separate and distinct biological processes. The identification of ERbeta specific ligands could further enhance our understanding of ERbeta biology. In addition, compounds targeting ERbeta may prove useful as therapeutic agents with activity profiles distinguishable from that of estradiol. To discover novel selective ligands for ERbeta, we developed and characterized a cell-based Gal4-ERbeta beta-lactamase reporter gene assay (GERTA) in CHO cells for the ligand-induced activation of the human ERbeta. The sensitivity and selectivity of this assay were found to be comparable to those of an ER ligand-binding assay. The assay was optimized for screening in an ultra high throughput 3456-well nanoplate format and was successfully used to screen a large compound collection for ERbeta agonists. Compounds identified in a primary screen were tested in an in vitro ligand-binding assay to characterize further the selectivity and potency for ERbeta.

Highly potent growth hormone secretagogues.

During an effort to search for more potent growth hormone secretagogues, we discovered a class of compounds of which the best compound 8 was 7-fold more active in vitro than the best compound in the series we revealed before [Tata, J. R.; Lu, Z.; Jacks, T. M.; Schleim, K. D.; Cheng, K.; Wei, L.; Chan, W.-S.; Butler, B.; Tsou, N.; Leung, K.; Chiu, S.-H. L.; Hickey, G. J.; Smith, R. G.; Patchett, A. A. Bioorg. Med. Chem. Lett.1997, 7, 2319.]. Animal studies show that compound 8 can stimulate growth hormone release at the oral dose as low as 0.06 mpk. Chemistry and biological studies are discussed.

Estrogen receptor ligands. Part 16: 2-Aryl indoles as highly subtype selective ligands for ERalpha.

A novel class of indole ligands for estrogen receptor alpha have been discovered which exhibit potent affinity and high selectivity. Substitution of the bazedoxifene skeleton to the linker present in the HTS lead 1a provided 22b which was found to be 130-fold alpha-selective and acted as an antagonist of estradiol activity in uterine tissue and MCF-7 cancer cells.

Bridged androstenediol analogs as ER-beta selective SERMs.

A series of bridged androstenediol derivatives was prepared. The bridged compounds exhibited reduced ER-beta selectivity relative to uncyclized analogs.

Androstene-3,5-dienes as ER-beta selective SERMs.

A series of androstene-3,5-diene derivatives were prepared. Despite lacking the C-3 hydroxyl previously believed necessary for ER activity, some of the analogs retained surprising affinity for ER-beta. For example, diene 4 retained excellent selectivity and potency as an ER-beta agonist and was more selective for ER-beta over the androgen receptor (AR).

Androstenediol analogs as ER-beta-selective SERMs.

A series of 19-substituted androstenediol derivatives was prepared. Some of the novel analogs were surprisingly potent and selective ligands for ER-beta.

Estrogen receptor ligands. Part 11: Synthesis and activity of isochromans and isothiochromans.

The ring oxygen and sulfur analogs of lasofoxifene, 1a and 1b, were synthesized in an attempt to impart ERalpha selectivity, as found in the closely related dihydrobenzoxathiin compound I, recently discovered in these laboratories. The resulting isochroman and isothiochroman compounds were found to exhibit equipotent binding affinities to the ER isoforms and were less active in the inhibition of estradiol-triggered uterine growth when compared to I and lasofoxifene.

Estrogen receptor ligands. Part 14: application of novel antagonist side chains to existing platforms.

Two novel side chains which had previously been found to enhance antagonist activity in the dihydrobenzoxathiin SERM series were applied to three existing platforms. The novel side chains did not improve the antagonist activity of the existing platforms.

Estrogen receptor ligands. Part 13: Dihydrobenzoxathiin SERAMs with an optimized antagonist side chain.

An optimized side chain for dihydrobenzoxathiin SERAMs was discovered and attached to four dihydrobenzoxathiin platforms. The novel SERAMs show exceptional estrogen antagonist activity in uterine tissue and an MCF-7 breast cancer cell assay.

Estrogen receptor ligands. Part 9: Dihydrobenzoxathiin SERAMs with alkyl substituted pyrrolidine side chains and linkers.

A series of dihydrobenzoxathiin SERAMs with alkylated pyrrolidine side chains or alkylated linkers was prepared. Minor modifications in the side chain or linker resulted in significant effects on biological activity, especially in uterine tissue.

Estrogen receptor ligands. Part 10: Chromanes: old scaffolds for new SERAMs.

The discovery, synthesis, and SAR of chromanes as ER alpha subtype selective ligands are described. X-ray studies revealed that the origin of the ER alpha-selectivity resulted from a C-4 trans methyl substitution to the cis-2,3-diphenyl-chromane platform. Selected compounds from this class demonstrated very potent in vivo antagonism of estradiol in an immature rat uterine weight assay, effectively inhibited ovariectomy-induced bone resorption in a 42 days treatment paradigm, and lowered serum cholesterol levels in ovx'd adult rat models. The best antagonists 8F and 12F also exhibited potent inhibition of MCF-7 cell growth and were shown to be estrogen receptor down-regulators (SERDs).

Comparison of 2-phenylspiroindenes and 2-phenylspiroindenediones as estrogen receptor ligands--modeling and binding data don't agree!

A series of 2-phenylspiroindenediones was prepared. The spiroindenediones were found to be less active than the corresponding spiroindenes as estrogen receptor ligands and failed to demonstrate the receptor subtype selectivity that had been anticipated from molecular modeling.

Estrogen receptor ligands. Part 3: The SAR of dihydrobenzoxathiin SERMs.

A series of 3-alkyl, 3-cycloalkyl, and 3-heteroaryl dihydrobenzoxathiin analogs 1 were prepared and evaluated for estrogen/anti-estrogen activity in both in vitro and in vivo models. In general, the compounds were found to exhibit a high degree of selectivity for ER alpha over ER beta, but were less potent than the original lead compound 1a in the inhibition of estradiol-driven uterine proliferation.

Estrogen receptor ligands. Part 4: The SAR of the syn-dihydrobenzoxathiin SERAMs.

A series of estrogen receptor ligands based on a dihydrobenzoxathiin scaffold is described and evaluated for estrogen/anti-estrogen activity in both in vitro and in vivo models. The most active analogue, 22, was found to be 40-fold ERalpha selective in a competitive binding assay, and 22 demonstrated very potent in vivo antagonism of estradiol driven proliferation in an immature rat uterine weight gain assay.

Estrogen receptor ligands. Part 1: The discovery of flavanoids with subtype selectivity.

A class of flavanoids exhibiting a high degree of selectivity for ERalpha over ERbeta has been discovered. The most active analogue 6 was found to be 66-fold ERalpha-selective and demonstrated uterine estradiol antagonism.

Substituted bridged phenyl piperidines: orally active growth hormone secretagogues.

A new series of growth hormone secretagogues have been discovered. The best compound, 26j, shows excellent ability to release growth hormone both in vitro and in vivo. The synthesis and biological activity of these compounds are discussed.

Estrogen receptor ligands. Part 6: Synthesis and binding affinity of dihydrobenzodithiins.

Dihydrobenzodithiin compounds (1-6) were prepared to explore the expansion of the dihydrobenzoxathiin lead compounds I-III as SERAMs (Selective Estrogen Receptor Alpha Modulators). The dihydrobenzodithiin compounds generally maintained a high degree of selectivity for ERalpha over ERbeta, however, they lacked the in vivo antagonism/agonism activity exhibited by the lead class in an immature rat uterine growth model.

Estrogen receptor ligands. Part 5: The SAR of dihydrobenzoxathiins containing modified basic side chains.

Dihydrobenzoxathiin analogs (1-11) with modifications on the basic side chain region were prepared and evaluated for estrogen/anti-estrogen activity in both in vitro and in vivo models. The compounds generally maintained a high degree of selectivity for ERalpha over ERbeta, similar to the original lead compound I. Many of the compounds also maintained high potency in the inhibition of human carcinoma MCF-7 cell growth. However, all were less potent in the inhibition of estradiol-triggered uterine growth. This work demonstrates the sensitive nature of modification to the antagonist basic side chain region.