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1.
Phys Chem Chem Phys ; 26(9): 7907-7919, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38376855

RESUMO

The partition coefficient (log P) is an important physicochemical property that provides information regarding a molecule's pharmacokinetics, toxicity, and bioavailability. Methods to accurately predict the partition coefficient have the potential to accelerate drug design. In an effort to test current methods and explore new computational techniques, the statistical assessment of the modeling of proteins and ligands (SAMPL) has established a blind prediction challenge. The ninth iteration challenge was to predict the toluene-water partition coefficient (log Ptol/w) of sixteen drug molecules. Herein, three approaches are reported broadly under the categories of quantum mechanics (QM), molecular mechanics (MM), and data-driven machine learning (ML). The three blind submissions yield mean unsigned errors (MUE) ranging from 1.53-2.93 log Ptol/w units. The MUEs were reduced to 1.00 log Ptol/w for the QM methods. While MM and ML methods outperformed DFT approaches for challenge molecules with fewer rotational degrees of freedom, they suffered for the larger molecules in this dataset. Overall, DFT functionals paired with a triple-ζ basis set were the simplest and most effective tool to obtain quantitatively accurate partition coefficients.

2.
Infect Prev Pract ; 2(1): 100032, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34368688

RESUMO

BACKGROUND: Mitigating surface contamination by microbes such as S. aureus, Salmonella enterica, or Klebsiella pneumoniae, is an ongoing problem in hospital and food production environments. AIM: To determine whether addition of buffering solution to source water used for manufacture of aqueous ozone increases ozone efficacy against ozone-resistant bacterial species. METHODS: Antimicrobial effects of aqueous ozone were studied in combination with acetate, propionate, or butyrate short chain fatty acids (SCFA) as well as citrate or oxalate buffer formulations against Staphylococcus aureus on glass coupons. Aqueous ozone combined with an acetate buffer was also evaluated against Salmonella enterica and Klebsiella pneumoniae. FINDINGS: The acetate, propionate, and butyrate buffered aqueous ozone combinations had a significant 3-4 log reduction of S. aureus (P<0.05) colony forming unit (CFU), while citrate or oxalate buffered aqueous ozone, although statistically significant versus buffer alone, had less activity. Treatment of S. aureus, S. enterica, or K. pneumoniae with acetate buffered aqueous ozone also resulted in a 4 log or greater reduction in CFUs post-treatment for all three species, versus treatment with water alone. CONCLUSIONS: All buffer systems tested had a significantly greater reduction in CFUs following treatment with the combination of buffer and ozone, compared to treatment with buffer or ozone individually, which has not been previously reported for hard surfaces. These results suggest that SCFA buffered ozone has greater anti-bacterial activity relative to either agent alone, and the activity is independent of the buffering activity. Thus, these formulations have potential to sanitize without residues, using an environmentally conscious formulation.

3.
Front Microbiol ; 9: 3180, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30671030

RESUMO

Currently, the most utilized antimicrobial in processing facilities is peracetic acid, PAA; however, this chemical is increasingly recognized as a hazard to human health. Preliminary evidence suggests that ozone, when introduced in a specific manner, can reduce the noxious nature of PAA. Therefore, the objective of the current study was to evaluate the efficacy of TetraClean Systems aqueous ozone, O3, in combination with PAA as an antimicrobial spray on whole chicken carcasses. This trial used 70 whole hen carcasses (7 treatments; 10 replications) that were inoculated in a 400 mL cocktail containing Salmonella, Escherichia coli, and Campylobacter (107 CFU/mL) and allowed to adhere for 60 min at 4°C for a final concentration of 105 to 106 CFU/g. The experimental 5 s (4×) spray treatments included: a no treatment negative control, TW; TW + O3 (10 ppm), TW + PAA (50 ppm), TW + PAA (500 ppm), TW + O3 + PAA (50 ppm), and TW + O3 + PAA (500 ppm). During treatment application, ambient PAA vapor was measured with a ChemDAQ Safecide PAA vapor sensor. After treatment, carcasses were immediately rinsed in 400 mL of nBPW for 2 min. Following rinsing, the dot method was utilizing for enumeration with 10 µL of rinsate being serially diluted, plated on XLD and mCCDA agar, and incubated aerobically at 37°C for 24 h or microaerophilically at 42°C for 48 h. Log-transformed counts were analyzed using ANOVA in JMP 14.0. Means were separated using Tukey's HSD when P ≤ 0.05. There was a significant treatment effect among Salmonella, E. coli, and Campylobacter counts, and a significant treatment effect among ambient PAA (P < 0.05). TW + O3 + PAA (500 ppm), reduced Salmonella significantly compared to TW (5.71 and 6.30 log CFU/g). Furthermore, TW + PAA (500 ppm), reduced the presence of E. coli significantly compared to TW or no treated control (5.57 and 6.18 log CFU/g). Also, TW + PAA (50 ppm), TW + PAA (500 ppm), and TW + O3 + PAA (500 ppm) significantly reduced Campylobacter compared to carcasses not treated (4.80, 4.81, and 4.86 log CFU/g). Lastly, the addition of ozone significantly reduced the ambient PAA when O3 was added to 500 ppm of PAA, as TW + O3 + PAA (500 ppm) produced less ambient PAA than TW + PAA (500 ppm) (0.052 and 0.565 ppm). In conclusion, the addition of ozone to PAA may demonstrated the ability to effectively reduce ambient PAA, thus increasing employee safety.

4.
Ind Health ; 55(6): 555-563, 2017 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-29033403

RESUMO

A collaborative approach, involving resources and expertise from several countries, was used to develop a test cell to measure cumulative permeation by a solid-state collection technique. The new technique was developed to measure the permeation of pesticide active ingredients and other chemicals with low vapor pressure that would otherwise be difficult to test via standard techniques. The development process is described and the results from the final chosen test method are reported. Inter-laboratory studies were conducted to further refine the new method and determine repeatability and reliability. The revised test method has been approved as a new ISO/EN standard to measure permeation of chemicals with low vapor pressure and/or solubility in water.


Assuntos
Teste de Materiais/métodos , Praguicidas , Roupa de Proteção/normas , Compostos de Anilina , Herbicidas , Permeabilidade , Reprodutibilidade dos Testes
5.
Antimicrob Agents Chemother ; 58(3): 1279-83, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24041885

RESUMO

Omadacycline is a novel first-in-class aminomethylcycline with potent activity against important skin and pneumonia pathogens, including community-acquired methicillin-resistant Staphylococcus aureus (MRSA), ß-hemolytic streptococci, penicillin-resistant Streptococcus pneumoniae, Haemophilus influenzae, and Legionella. In this work, the mechanism of action for omadacycline was further elucidated using a variety of models. Functional assays demonstrated that omadacycline is active against strains expressing the two main forms of tetracycline resistance (efflux and ribosomal protection). Macromolecular synthesis experiments confirmed that the primary effect of omadacycline is on bacterial protein synthesis, inhibiting protein synthesis with a potency greater than that of tetracycline. Biophysical studies with isolated ribosomes confirmed that the binding site for omadacycline is similar to that for tetracycline. In addition, unlike tetracycline, omadacycline is active in vitro in the presence of the ribosomal protection protein Tet(O).


Assuntos
Antibacterianos/farmacologia , Tetraciclinas/farmacologia , Bactérias/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , Ribossomos/efeitos dos fármacos , Resistência a Tetraciclina
6.
J Reprod Med ; 58(5-6): 187-94, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23763001

RESUMO

OBJECTIVE: To compare the accuracy of a new combination monoclonal/polyclonal immunoassay point-of-care test with that of current conventional clinical assessment for diagnosis of ruptured amniotic membranes. STUDY DESIGN: This was a multicenter prospective observational study performed in patients presenting with signs or symptoms of ruptured amniotic membranes. This clinical trial included 3 sites in the United States. Initial evaluation included both the standard clinical assessment for rupture of membranes (ROM) (speculum examination for fluid pooling, ferning, and nitrazine test), as well as the use of a new combination immunoassay test containing a combination monoclonal/polyclonal antibody approach to detect placental protein 12 (PP12) and alpha-fetoprotein (AFP). ROM was diagnosed if fluid was seen leaking from the cervical os, or if 2 of the 3 conditions were present: pooling of fluid, positive nitrazine test, or ferning. ROM was confirmed on review of the medical records following delivery. RESULTS: Of the 285 patients (15-42 weeks of gestation), the false positive rate for the new combination immunoassay test was 9% and the false negative rate was 0.5%, sensitivity 99%, specificity 91%, positive and negative predictive values of 95% and 99%, respectively. The conventional clinical evaluation's sensitivity was 85%, specificity 98%, with positive and negative predictive values of 99% and 77%. Ferning's sensitivity was 99%, specificity 72%, with positive and negative predictive values of 80% and 99%. Nitrazine testing's sensitivity was 93%, specificity 83%, with positive and negative predictive values of 90% and 88%. CONCLUSION: This combination monoclonal and polyclonal immunoassay test that detects PP12 and AFP has an efficacy comparable to conventional testing and better than the individual components of conventional testing (ferning, nitrazine), is a quick and easy-to-use test that can be performed by a wider variety of care providers, and can improve triage and management of patients suspected of ROM.


Assuntos
Ruptura Prematura de Membranas Fetais/diagnóstico , Idade Gestacional , Imunoensaio/métodos , Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/análise , alfa-Fetoproteínas/análise , Adolescente , Adulto , Líquido Amniótico/química , Anticorpos Monoclonais , Estudos de Coortes , Reações Falso-Positivas , Feminino , Humanos , Gravidez , Estudos Prospectivos , Sensibilidade e Especificidade
7.
Antimicrob Agents Chemother ; 57(7): 3131-6, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23629719

RESUMO

With increasing resistance to existing antimalarials, there is an urgent need to discover new drugs at affordable prices for countries in which malaria is endemic. One approach to the development of new antimalarial drugs is to improve upon existing antimalarial agents, such as the tetracyclines. Tetracyclines exhibit potent, albeit relatively slow, action against malaria parasites, and doxycycline is used for both treatment (with other agents) and prevention of malaria. We synthesized 18 novel 7-position modified tetracycline derivatives and screened them for activity against cultured malaria parasites. Compounds with potent in vitro activity and other favorable drug properties were further tested in a rodent malaria model. Ten compounds inhibited the development of cultured Plasmodium falciparum with a 50% inhibitory concentration (IC50) after 96 h of incubation of <30 nM, demonstrating activity markedly superior to that of doxycycline (IC50 at 96 h of 320 nM). Most compounds showed little mammalian cell cytotoxicity and no evidence of in vitro phototoxicity. In a murine Plasmodium berghei model, 13 compounds demonstrated improved activity relative to that of doxycycline. In summary, 7-position modified tetracyclines offer improved activity against malaria parasites compared to doxycycline. Optimized compounds may allow lower doses for treatment and chemoprophylaxis. If safety margins are adequate, dosing in children, the group at greatest risk for malaria in countries in which it is endemic, may be feasible.


Assuntos
Antimaláricos/farmacologia , Malária/tratamento farmacológico , Malária/prevenção & controle , Plasmodium berghei/efeitos dos fármacos , Tetraciclinas/farmacologia , Animais , Resistência a Medicamentos , Camundongos , Testes de Sensibilidade Parasitária
8.
Antimicrob Agents Chemother ; 56(11): 5650-4, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22908151

RESUMO

A randomized, investigator-blind, multicenter phase 2 trial involving patients with complicated skin and skin structure infections (cSSSI) compared the safety and efficacy of omadacycline, a broad-spectrum agent with activity against methicillin-resistant Staphylococcus aureus (MRSA), to those of linezolid (with or without aztreonam). Patients were randomized 1:1 to omadacycline (100 mg intravenously [i.v.] once a day [QD] with an option to transition to 200 mg orally QD) or linezolid (600 mg i.v. twice daily [BID] with an option to transition to 600 mg orally BID) at 11 U.S. sites. Patients suspected or documented to have infections caused by Gram-negative bacteria were given aztreonam (2 g i.v. every 12 h [q12h]) if randomized to linezolid or matching placebo infusions if randomized to omadacycline. Adverse events were reported in 46 (41.4%) omadacycline-treated and 55 (50.9%) linezolid-treated patients. Adverse events related to treatment were assessed by investigators in 24 (21.6%) omadacycline-treated and 33 (30.6%) linezolid-treated patients. The gastrointestinal tract was most commonly involved, with adverse events reported in 21 (18.9%) patients exposed to omadacycline and 20 (18.5%) exposed to linezolid. Rates of successful clinical response in the intent-to-treat (ITT) and clinical evaluable (CE) populations favored omadacycline (ITT, 88.3% versus 75.9%; 95% confidence interval [CI], 1.9 to 22.9; CE, 98.0% versus 93.2%; 95% CI, -1.7 to 11.3). For microbiologically evaluable (ME) patients with S. aureus infections, the clinical success rates were 97.2% (70/72) in omadacycline-treated and 92.7% (51/55) in linezolid-treated patients. This phase 2 experience supports conclusions that omadacycline is well tolerated in cSSSI patients and that this aminomethylcycline has potential to be an effective treatment for serious skin infections.


Assuntos
Acetamidas/administração & dosagem , Antibacterianos/administração & dosagem , Aztreonam/administração & dosagem , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Minociclina/administração & dosagem , Oxazolidinonas/administração & dosagem , Dermatopatias Bacterianas/tratamento farmacológico , Pele/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Acetamidas/efeitos adversos , Adolescente , Adulto , Idoso , Antibacterianos/efeitos adversos , Aztreonam/efeitos adversos , Esquema de Medicação , Feminino , Humanos , Injeções Intravenosas , Linezolida , Masculino , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Pessoa de Meia-Idade , Minociclina/efeitos adversos , Minociclina/análogos & derivados , Oxazolidinonas/efeitos adversos , Placebos , Pele/microbiologia , Dermatopatias Bacterianas/microbiologia , Infecções Estafilocócicas/microbiologia , Resultado do Tratamento
9.
Bioorg Med Chem Lett ; 20(11): 3380-3, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20434913

RESUMO

ExsA is a multiple adaptational response (MAR) transcription factor, regulating the expression of a virulence determinant, the type III secretion system (T3SS) in Pseudomonas aeruginosa. Non-cytotoxic, non-antibacterial N-hydroxybenzimidazoles were identified as effective inhibitors of ExsA-DNA binding, and their potential utility as anti-virulence agents for P. aeruginosa was demonstrated in a whole cell assay. Select N-hydroxybenzimidazole inhibitors were stable in an in vitro human liver microsomal assay.


Assuntos
Benzimidazóis/antagonistas & inibidores , Pseudomonas aeruginosa/efeitos dos fármacos , Fatores de Transcrição/antagonistas & inibidores , Virulência/efeitos dos fármacos , Humanos , Microssomos Hepáticos/efeitos dos fármacos , Pseudomonas aeruginosa/metabolismo , Pseudomonas aeruginosa/patogenicidade
10.
Inflamm Res ; 59(1): 15-22, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19568691

RESUMO

BACKGROUND: Inflammation plays a central role in many neurodegenerative diseases, including Parkinson's, Alzheimer's, multiple sclerosis, amyotrophic lateral sclerosis, and AIDS dementia. Microglia are the resident macrophages of the central nervous system and are the cells primarily responsible for the inflammatory component of these diseases. METHODS: Using gene expression profiling, we compared the profile of the neurospecific microglial cell line BV-2 after LPS stimulation to that of a macrophage cell line (J774A.1) stimulated with LPS. RESULTS: A set of 77 genes that were modulated only in microglial cells after LPS stimulation was identified. One gene of interest, Gng12, was investigated further to determine its ability to modify the inflammatory response. Specifically, Gng12 mRNA levels were transiently increased after LPS stimulation. In addition, overall levels of Gng12 mRNA after LPS stimulation were significantly higher in BV-2 cells as compared to macrophage cells. CONCLUSION: Modulating Gng12 mRNA levels using RNAi revealed a novel role for the factor in the negative regulation of the overall inflammatory response as based on effects on nitrite and TNFalpha levels. These data suggest that Gng12 is a negative regulator of the LPS response and may be an important factor in the overall inflammatory signaling cascade.


Assuntos
Proteínas de Ligação ao GTP/metabolismo , Inflamação/metabolismo , Microglia/metabolismo , Animais , Linhagem Celular , Subunidades gama da Proteína de Ligação ao GTP/genética , Subunidades gama da Proteína de Ligação ao GTP/fisiologia , Proteínas de Ligação ao GTP/genética , Perfilação da Expressão Gênica , Inflamação/induzido quimicamente , Lipopolissacarídeos/efeitos adversos , Lipopolissacarídeos/farmacologia , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Camundongos , Microglia/citologia , Microglia/efeitos dos fármacos , Nitritos/metabolismo , Interferência de RNA , RNA Mensageiro/metabolismo , Fator de Necrose Tumoral alfa/metabolismo
11.
Sci Transl Med ; 1(5): 5ra12, 2009 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-20161659

RESUMO

There is at present no cure or effective therapy for spinal muscular atrophy (SMA), a neurodegenerative disease that is the leading genetic cause of infant mortality. SMA usually results from loss of the SMN1 (survival of motor neuron 1) gene, which leads to selective motor neuron degeneration. SMN2 is nearly identical to SMN1 but has a nucleotide replacement that causes exon 7 skipping, resulting in a truncated, unstable version of the SMA protein. SMN2 is present in all SMA patients, and correcting SMN2 splicing is a promising approach for SMA therapy. We identified a tetracycline-like compound, PTK-SMA1, which stimulates exon 7 splicing and increases SMN protein levels in vitro and in vivo in mice. Unlike previously identified molecules that stimulate SMN production via SMN2 promoter activation or undefined mechanisms, PTK-SMA1 is a unique therapeutic candidate in that it acts by directly stimulating splicing of exon 7. Synthetic small-molecule compounds such as PTK-SMA1 offer an alternative to antisense oligonucleotide therapies that are being developed as therapeutics for a number of disease-associated splicing defects.


Assuntos
Éxons , Atrofia Muscular Espinal/tratamento farmacológico , Splicing de RNA/efeitos dos fármacos , Tetraciclinas/farmacologia , Animais , Humanos , Camundongos , Atrofia Muscular Espinal/genética , Proteína 2 de Sobrevivência do Neurônio Motor/genética
12.
Angew Chem Int Ed Engl ; 47(15): 2754-87, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18311737

RESUMO

In recent years the design of chemical structures of liquid-crystalline materials has developed rapidly, and in many cases changed radically. Since Reinitzer's days, liquid crystals have either been classed as rodlike or disclike, with combinations of the two leading to phasmidic liquid crystals. The discovery that materials with bent molecular structures exhibited whole new families of mesophases inspired investigations into the liquid-crystal properties of materials with widely varying molecular topologies-from pyramids to crosses to dendritic molecules. As a result of conformational change, supermolecular materials can have deformable molecular structures, which can stabilize mesophase formation, and some materials that are non-mesogenic, on complexation form supramolecular liquid crystals. The formation of mesophases by individual molecular systems is a process of self-organization, whereas the mesophases of supramolecular systems are formed by self-assembly and self-organization. Herein we show 1) deformable molecular shapes and topologies of supermolecular and self-assembled supramolecular systems; 2) surface recognition processes of superstructures; and 3) that the transmission of those structures and their amplification can lead to unusual mesomorphic behavior where conventional continuum theory is not suitable for their description.


Assuntos
Cristais Líquidos/química , Nanoestruturas/química , Glicolipídeos/química , Cristais Líquidos/ultraestrutura , Modelos Moleculares , Estereoisomerismo , Sacarose/química
13.
Obstet Gynecol Surv ; 63(3): 163-81, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18279543

RESUMO

Recent clinical data on selective estrogen receptor modulators (SERMs) have provided the basis for reassessment of the SERM concept. The molecular basis of SERM activity involves binding of the ligand SERM to the estrogen receptor (ER), causing conformational changes which facilitate interactions with coactivator or corepressor proteins, and subsequently initiate or suppress transcription of target genes. SERM activity is intrinsic to each ER ligand, which accomplishes its unique profile by specific interactions in the target cell, leading to tissue selective actions. We discuss the estrogenic and anti-estrogenic effects of early SERMs, such as clomiphene citrate, used for treatment of ovulation induction, and the triphenylethylene, tamoxifen, which has ER antagonist activity in the breast, and is used for prevention and treatment of ER-positive breast cancer. Since the development of tamoxifen, other triphenylethylene SERMs have been studied for breast cancer prevention, including droloxifene, idoxifene, toremifene, and ospemifene. Other SERMs have entered clinical development more recently, including benzothiophenes (raloxifene and arzoxifene), benzopyrans (ormeloxifene, levormeloxifene, and EM-800), lasofoxifene, pipendoxifene, bazedoxifene, HMR-3339, and fulvestrant, an anti-estrogen which is approved for breast cancer treatment. SERMs have effects on tissues containing ER, such as the breast, bone, uterine and genitourinary tissues, and brain, and on markers of cardiovascular risk. Current evidence indicates that each SERM has a unique array of clinical activities. Differences in the patterns of action of SERMs suggest that each clinical end point must be evaluated individually, and conclusions about any particular SERM can only be established through appropriate clinical trials.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Receptores de Estrogênio/efeitos dos fármacos , Moduladores Seletivos de Receptor Estrogênico , Densidade Óssea/efeitos dos fármacos , Neoplasias da Mama/prevenção & controle , Feminino , Humanos , Indução da Ovulação/métodos , Pós-Menopausa/efeitos dos fármacos , Moduladores Seletivos de Receptor Estrogênico/química , Moduladores Seletivos de Receptor Estrogênico/classificação , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Sistema Urogenital/efeitos dos fármacos
16.
Womens Health (Lond) ; 2(2): 199-210, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19803890

RESUMO

Selective estrogen-receptor modulators are molecules with specific estrogen-receptor binding affinity. Each selective estrogen-receptor modulator induces a unique conformation in the ligand-receptor complex, which leads to transcriptional activation and/or inhibition. Raloxifene 60 mg/day, a benzothiophene selective estrogen-receptor modulator, is approved for the prevention and treatment of postmenopausal osteoporosis. This article provides an update on new studies and further analyses of clinical trial data for raloxifene. The Multiple Outcomes of Raloxifene Evaluation (MORE) trial of women with osteoporosis has described the efficacy of raloxifene in decreasing vertebral fracture risk over 4 years. The Continuing Outcomes Relevant to Evista((R)) (CORE) trial, designed to assess the effects of raloxifene on breast cancer prevention, is a 4-year continuation of MORE. The skeletal and cardiovascular effects of raloxifene in the CORE study were similar to those observed in MORE. The relative risk of developing breast cancer was significantly decreased in women treated with raloxifene, compared with placebo, after 4 years in MORE and 8 years in the CORE trial. The incidence of uterine bleeding, endometrial hyperplasia and endometrial cancer was similar between raloxifene and placebo after 8 years of treatment. Raloxifene use is associated with a higher incidence of hot flashes and leg cramps, and an increased risk of venous thromboembolic events.

18.
Endocrinology ; 146(10): 4524-35, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16002528

RESUMO

The use of selective estrogen receptor modulators for the treatment of estrogen-dependent diseases in premenopausal women has been hindered by undesirable ovarian stimulation and associated risks of ovarian cysts. We have identified a selective estrogen receptor modulator compound (LY2066948) that is a strong estrogen antagonist in the uterus yet has minimal effects on the ovaries of rats. LY2066948 binds with high affinity to both estrogen receptors and has potent estrogen antagonist activity in human uterine and breast cancer cells. Oral administration of LY2066948 to immature rats blocked uterine weight gain induced by ethynyl estradiol with an ED50 of 0.07 mg/kg. Studies in mature rats demonstrated that LY2066948 decreases uterine weight by 51% after 35 d treatment, confirming potent uterine antagonist activity over several estrous cycles. This strong uterine response contrasted with the minimal effects on the ovaries: serum estradiol levels remained within the normal range, whereas histologic evaluation showed granulosa cell hyperplasia in few of the rats. Bone studies demonstrated that LY2066948 prevented ovariectomy-induced bone loss and treatment of ovary-intact rats caused no bone loss, confirming estrogen receptor agonist skeletal effects. Collectively, these data show that LY2066948 exhibits a tissue-specific profile consistent with strong antagonist activity in the uterus, agonist activity in bone, and minimal effects in the ovaries.


Assuntos
Osso e Ossos/fisiologia , Naftalenos/farmacologia , Indução da Ovulação , Piperidinas/farmacologia , Receptores de Estrogênio/fisiologia , Útero/fisiologia , Animais , Osso e Ossos/efeitos dos fármacos , Linhagem Celular Tumoral , Etinilestradiol/farmacologia , Feminino , Humanos , Cinética , Ovariectomia , Ratos , Receptores de Estrogênio/agonistas , Receptores de Estrogênio/antagonistas & inibidores , Receptores de Estrogênio/efeitos dos fármacos , Maturidade Sexual , Útero/efeitos dos fármacos
19.
J Bone Miner Res ; 19(9): 1518-24, 2004 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-15312253

RESUMO

UNLABELLED: In healthy middle-aged men, raloxifene treatment was associated with increased serum estradiol and decreased biochemical markers of bone turnover in subjects with estradiol levels below a threshold of 101.8 pM. INTRODUCTION: We investigated the effects of the selective estrogen receptor modulator raloxifene on bone remodeling in healthy middle-aged men. MATERIALS AND METHODS: Forty-three healthy eugonadal men (mean age, 56 years; range, 49-70 years) were enrolled in a randomized placebo-controlled, double-blind, two-sequence crossover study. The subjects received either raloxifene 120 mg/day or placebo for 6 weeks, followed by a 2-month washout period, before crossing over. To predict changes of urinary total deoxypyridinoline/creatinine on raloxifene treatment, we used a logistic regression model to determine cut-off values of sex hormones for highest sensitivity and specificity. RESULTS: In the whole group, raloxifene treatment was associated with an increase in serum sex hormones, that is, total testosterone (+13%, p < 0.01), bioavailable testosterone (+11%, p = 0.02), total estradiol (+11%, p < 0.002), and bioavailable estradiol (+11%, p = 0.035), and with a decrease in serum osteocalcin (-13%, p < 0.05) and serum total alkaline phosphatase (-6%, p < 0.05). Other biochemical markers of bone turnover remained unchanged. Using a logistic regression model to predict changes in urinary deoxypyridoline, we calculated thresholds for total (101.8 pM) and bioavailable (4.79 pM) estradiol, as well as for total (19.4 nM) and bioavailable (0.35 nM) testosterone. Raloxifene treatment was associated with an increase in serum estradiol and decrease in biochemical markers of bone turnover in men with estradiol values below these estradiol thresholds, without any significant change in subjects with values above them. Similarly, raloxifene treatment was associated with an increase in serum testosterone and a decrease in biochemical markers of bone turnover in those with baseline testosterone values below the testosterone thresholds. The association between antiresorptive effects of raloxifene and low sex hormone levels was more pronounced for estradiol than for testosterone. CONCLUSIONS: The antiresorptive effect of raloxifene was only detectable in men with low baseline estradiol levels. Unlike in postmenopausal women, the increase of estradiol may contribute to the antiresorptive effect of raloxifene in men.


Assuntos
Remodelação Óssea/efeitos dos fármacos , Estradiol/sangue , Cloridrato de Raloxifeno/farmacologia , Testosterona/sangue , Idoso , Aminoácidos/urina , Biomarcadores/análise , Biomarcadores/sangue , Biomarcadores/urina , Creatina/urina , Estudos Cross-Over , Método Duplo-Cego , Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Placebos , Testosterona/urina
20.
Arch Intern Med ; 164(8): 871-9, 2004 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-15111373

RESUMO

BACKGROUND: Although many studies have assessed the effects of estrogen and raloxifene hydrochloride on bone mineral density and serum lipid concentrations, there are few direct comparative data. METHODS: Randomized placebo-controlled trial for 3 years, intention-to-treat analysis. Six hundred nineteen postmenopausal women with prior hysterectomy (mean age, 53.0 years) were studied in 38 centers in Europe, North America, Australasia, and South Africa. They were randomized to 60 mg/d or 150 mg/d of raloxifene, 0.625 mg/d of conjugated equine estrogen (CEE), or placebo. Bone density of the lumbar spine and proximal femur, biochemical markers of bone turnover, and fasting serum lipid concentrations were assessed for 3 years. RESULTS: Compared with baseline, bone density in the lumbar spine progressively declined by 2.0% in the placebo group (P <.05), was stable in the 2 raloxifene groups, and increased 4.6% in the subjects receiving CEE (P <.001). Effects in both raloxifene groups were different from those observed in the CEE and placebo groups (P <.001). Bone density in the total hip showed similar results. Conjugated equine estrogen produced significantly greater depression of serum osteocalcin, bone-specific alkaline phosphatase, and urine C-telopeptide, compared with raloxifene. Each of the active treatments caused comparable depression of low-density lipoprotein cholesterol below placebo levels (P <.001 at most time points). Raloxifene did not affect high-density lipoprotein cholesterol, whereas CEE increased it by 13.4% compared with placebo at 3 years (P <.001). Triglyceride concentrations increased 24.6% in the CEE group at 3 years (P <.003), a significantly greater change than in the raloxifene groups, which were 4.9% and 8.0% above baseline (P < or =.002) but not different from placebo. Urinary incontinence was reported in 11 women receiving CEE, but in only 1 or 2 in each of the other groups (P < or =.01 compared with the other groups). Hernias occurred less frequently in those receiving 150 mg/d of raloxifene or CEE (P =.03 vs placebo). CONCLUSIONS: Raloxifene and CEE have beneficial effects on bone density and bone turnover, although effects of CEE are more marked. Raloxifene and CEE produce different patterns of lipid responses and have distinct adverse effect profiles.


Assuntos
Densidade Óssea/efeitos dos fármacos , Osso e Ossos/metabolismo , Colesterol/sangue , Antagonistas de Estrogênios/farmacologia , Estrogênios Conjugados (USP)/farmacologia , Estrogênios/farmacologia , Lipídeos/sangue , Cloridrato de Raloxifeno/farmacologia , Fosfatase Alcalina/sangue , HDL-Colesterol/sangue , Colágeno/urina , Colágeno Tipo I , Método Duplo-Cego , Feminino , Humanos , Histerectomia , Lipoproteínas , Pessoa de Meia-Idade , Osteocalcina/sangue , Peptídeos/urina
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