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1.
AAPS PharmSciTech ; 25(6): 164, 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-38997569

RESUMO

This study employed a Quality by Design (QbD) approach to spray dry amorphousclotrimazole nanosuspension (CLT-NS) consisting of Soluplus® and microcrystallinecellulose. Using the Box-Behnken Design, a systematic evaluation was conducted toanalyze the impact of inlet temperature, % aspiration, and feed rate on the criticalquality attributes (CQAs) of the clotrimazole spray-dried nanosuspension (CLT-SDNS). In this study, regression analysis and ANOVA were employed to detect significantfactors and interactions, enabling the development of a predictive model for the spraydrying process. Following optimization, the CLT-SD-NS underwent analysis using Xraypowder diffraction (XRPD), Fourier transform infrared spectroscopy (FTIR), Dynamic Scanning Calorimetry (DSC), and in vitro dissolution studies. The resultsshowed significant variables, including inlet temperature, feed rate, and aspiration rate,affecting yield, redispersibility index (RDI), and moisture content of the final product. The models created for critical quality attributes (CQAs) showed statistical significanceat a p-value of 0.05. XRPD and DSC confirmed the amorphous state of CLT in theCLT-SD-NS, and FTIR indicated no interactions between CLT and excipients. In vitrodissolution studies showed improved dissolution rates for the CLT-SD-NS (3.12-foldincrease in DI water and 5.88-fold increase at pH 7.2 dissolution media), attributed torapidly redispersing nanosized amorphous CLT particles. The well-designed studyutilizing the Design of Experiments (DoE) methodology.


Assuntos
Clotrimazol , Nanopartículas , Suspensões , Clotrimazol/química , Clotrimazol/administração & dosagem , Nanopartículas/química , Suspensões/química , Secagem por Atomização , Química Farmacêutica/métodos , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Tamanho da Partícula , Varredura Diferencial de Calorimetria/métodos , Temperatura , Composição de Medicamentos/métodos , Polivinil/química , Difração de Raios X/métodos , Polietilenoglicóis
2.
BMC Womens Health ; 22(1): 113, 2022 04 12.
Artigo em Inglês | MEDLINE | ID: mdl-35413875

RESUMO

BACKGROUND: Female reproductive tract dysbiosis impacts implantation. However, whether gut dysbiosis influences implantation failure and whether it accompanies reproductive tract dysbiosis remains scantly explored. Herein, we examined the gut-vaginal microbiota axis in infertile women. METHODS: We recruited 11 fertile women as the controls, and a cohort of 20 infertile women, 10 of whom had recurrent implantation failure (RIF), and another 10 had unexplained infertility (UE). Using amplicon sequencing, which employs PCR to create sequences of DNA called amplicon, we compared the diversity, structure, and composition of faecal and vaginal bacteria of the controls with that of the infertile cohort. Of note, we could only sequence 8 vaginal samples in each group (n = 24/31). RESULT: Compared with the controls, α-diversity and ß-diversity of the gut bacteria among the infertile groups differed significantly (p < 0.05). Taxa analysis revealed enrichment of Gram-positive bacteria in the RIF group, whereas Gram-negative bacteria were relatively abundant in the UE group. Strikingly, mucus-producing genera declined in the infertile cohort (p < 0.05). Hungatella, associated with trimethylamine N-oxide (TMAO) production, were enriched in the infertile cohort (p < 0.05). Vaginal microbiota was dominated by the genus Lactobacillus, with Lactobacillus iners AB-1 being the most abundant species across the groups. Compared with the infertile cohort, overgrowth of anaerobic bacteria, associated with vaginal dysbiosis, such as Leptotrichia and Snethia, occurred in the controls. CONCLUSION: The gut microbiota had little influence on the vaginal microbiota. Gut dysbiosis and vaginal eubiosis occurred in the infertile women, whereas the opposite trend occurred in the controls.


Assuntos
Infertilidade Feminina , Microbiota , Disbiose/complicações , Disbiose/microbiologia , Feminino , Humanos , RNA Ribossômico 16S/genética , Vagina/microbiologia
3.
J Biopharm Stat ; 30(4): 721-733, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32163316

RESUMO

Potency determination via bioassay is a relative measure that requires an evaluation of parallelism between the dose-response relationships of a reference standard and a sample material. Typical approaches for assessing parallelism include difference ([Formula: see text]-value) and equivalence tests. These traditional methods rely on a statistical assessment of model parameters as opposed to direct evaluation of the similarity of the dose-response curves. We propose a simple curve similarity approach that tests the hypothesis that the sample material is a dilution or concentration of the reference standard. The test is achieved by quantifying and normalizing the total area between the two curves and provides a single composite measure of parallelism. Both a frequentist and a Bayesian approach to the test are provided. We show through a simulation study that the curve similarity approach overcomes the drawbacks of the traditional methods and is effective at detecting parallelism and non-parallelism for bioassays.


Assuntos
Bioensaio/estatística & dados numéricos , Projetos de Pesquisa/estatística & dados numéricos , Animais , Teorema de Bayes , Simulação por Computador , Interpretação Estatística de Dados , Relação Dose-Resposta a Droga , Humanos , Modelos Estatísticos , Método de Monte Carlo , Equivalência Terapêutica
4.
Biotechnol Bioeng ; 115(3): 705-718, 2018 03.
Artigo em Inglês | MEDLINE | ID: mdl-29150961

RESUMO

Cross-linking of the Fcγ receptors expressed on the surface of hematopoietic cells by IgG immune complexes triggers the activation of key immune effector mechanisms, including antibody-dependent cell mediated cytotoxicity (ADCC). A conserved N-glycan positioned at the N-terminal region of the IgG CH 2 domain is critical in maintaining the quaternary structure of the molecule for Fcγ receptor engagement. The removal of a single core fucose residue from the N-glycan results in a considerable increase in affinity for FcγRIIIa leading to an enhanced receptor-mediated immunoeffector function. The enhanced potency of the molecule translates into a number of distinct advantages in the development of IgG antibodies for cancer therapy. In an effort to significantly increase the potency of an anti-CD20, IgG1 molecule, we selectively targeted the de novo GDP-fucose biosynthesis pathway of the host CHO cell line to generate >80% afucosylated IgG1 resulting in enhanced FcγRIIIa binding (13-fold) and in vitro ADCC cell-based activity (11-fold). In addition, this effective glycoengineering strategy also allowed for the utilization of the alternate GDP-fucose salvage pathway to provide a fast and efficient mechanism to manipulate the N-glycan fucosylation level to modulate IgG immune effector function.


Assuntos
Cricetulus/metabolismo , Imunoglobulina G/biossíntese , Engenharia de Proteínas , Rituximab/biossíntese , Animais , Cricetulus/genética , Glicosilação , Imunoglobulina G/genética , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/genética , Rituximab/genética
5.
Reprod Sci ; 31(8): 2273-2281, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38637475

RESUMO

Polycystic Ovary Syndrome (PCOS) is a multifaceted condition influenced by genetic, hormonal, and environmental factors. Among environmental factors, Bisphenol A (BPA)-a recognized endocrine disruptor-has been implicated in the development of PCOS. The study aimed to compare BPA levels in women diagnosed with PCOS with those in healthy controls, using the high-performance liquid chromatography (HPLC) technique. The study involved 80 women diagnosed with PCOS and 50 healthy control participants. Demographic and biochemical parameters were recorded, including age, Body Mass Index (BMI), and levels of testosterone, estradiol, Luteinizing Hormone (LH), Follicle Stimulating Hormone (FSH), Prolactin (PRL), Dehydroepiandrosterone Sulfate (DHEA-S), Thyroid Stimulating Hormone (TSH), and Insulin Resistance as measured by the Homeostatic Model Assessment (HOMA-IR). Furthermore, BPA levels were measured using the HPLC technique. Women with PCOS exhibited significantly higher mean age and BMI compared to healthy controls (p = 0.01, p < 0.0001, respectively). Additionally, higher levels of testosterone (p = 0.04), LH (p = 0.03) and BPA (p < 0.0001) were observed in women with PCOS. However, estradiol, FSH, PRL, LH/FSH ratio, DHEA-S, and TSH levels were not significantly different between the two groups. HOMA-IR levels were not recorded for the control group. A notable positive relationship emerged between Bisphenol A and luteinizing hormone (LH) levels (r = 0.23, p = 0.03), also significant negative correlation appeared between Bisphenol A and thyroid-stimulating hormone (TSH) levels. This study found that women with PCOS have elevated BPA levels compared with healthy controls, showing a need for further research on the relationship between BPA exposure and the development of PCOS.


Assuntos
Compostos Benzidrílicos , Disruptores Endócrinos , Fenóis , Síndrome do Ovário Policístico , Humanos , Feminino , Compostos Benzidrílicos/efeitos adversos , Compostos Benzidrílicos/sangue , Síndrome do Ovário Policístico/induzido quimicamente , Síndrome do Ovário Policístico/sangue , Fenóis/sangue , Adulto , Estudos de Casos e Controles , Disruptores Endócrinos/efeitos adversos , Disruptores Endócrinos/sangue , Adulto Jovem , Resistência à Insulina , Hormônio Luteinizante/sangue
6.
Sci Rep ; 13(1): 11967, 2023 07 24.
Artigo em Inglês | MEDLINE | ID: mdl-37488157

RESUMO

PCOS is a prevalent endocrine disorder among women of reproductive age, characterized by hormonal imbalances and metabolic disturbances. This study explores the correlation between gut microbial ß-glucuronidase and ß-glucosidase and PCOS, focusing on their association with hormone levels and other clinical parameters. In this case-control study, fecal samples were collected from women of reproductive age, both with and without PCOS. The analysis of gut ß-glucuronidase and ß-glucosidase enzymes was conducted with the other clinical parameters, including body mass index, hormone levels, and hirsutism. These factors were then subjected to correlation analysis. PCOS women showed significantly higher levels of ß-glucuronidase activity with a statistically significant P-value (0.05 ± 0.1 vs. 0.04 ± 0.1; P = 0.006) as well as ß-glucosidase activity (0.13 ± 0.08 vs. 0.09 ± 0.05; P = 0.06) compared to the controls. This study also revealed intriguing connections between the selected enzymes and hormone levels, particularly testosterone and estradiol. Gut microbial enzymes ß-glucuronidase and ß-glucosidase may be used as biomarkers for early detection and monitoring of PCOS in women with metabolic challenges. It could lead to improved diagnostic tools and treatment options.


Assuntos
Microbioma Gastrointestinal , Síndrome do Ovário Policístico , Feminino , Humanos , Glucuronidase , Estudos de Casos e Controles , beta-Glucosidase , Estradiol
7.
Int J Pharm ; 635: 122710, 2023 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-36773731

RESUMO

Punch sticking has been a leading drawback that has challenged successful tablet manufacturing since its initial conception. Due to the capricious nature of the complication, this can arise during any phase of the development process. Even now, identifying such a problem is a prerequisite during the initial stage of development. The present study evaluated the role of Aerosil®200, talc, and Syloid®244 as glidants in varying amounts ranging from 0.0 percent to 2.0 percent w/w on tablets sticking relatively to five different metal surfaces, with ketoprofen as the model drug. Powder rheology is a predictable technique used to calculate the sticking index. The sticking index of each formulation in comparison to each metal coupon was identified by calculating the kinematic angle of internal friction and the angle of wall friction using the shear cell test and wall friction test, respectively. Interestingly, glidants were found to reduce the sticking propensity of the powder blend in a concentration-dependent manner. In addition, the compression study validated the expected sticking tendency ranking order. According to the research data, the sticking index could effectively be utilized to envisage the possibility of tablet sticking, i.e., by selecting the formulation's excipient and their percentages or selecting appropriate punched metal surfaces in the tableting process.


Assuntos
Cetoprofeno , Pós , Comprimidos , Pressão , Excipientes , Composição de Medicamentos/métodos
8.
J Pharm Biomed Anal ; 191: 113577, 2020 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-32891042

RESUMO

The role of biotherapeutic proteins in the prevention and treatment of diseases such as cancers, infectious diseases, and autoimmune disorders continues to grow. The biological activity or "potency" of a biotherapeutic reflects its mechanism of action and thus its efficacy. The potency of these complex biomolecules cannot be quantitatively correlated to chemical and physical properties and thus must be determined by comparison to a reference standard, typically using a cell-based bioassay. This lack of an absolute method for determining potency, along with test method variability and potential for bias make assignment and monitoring of reference standard potency a major challenge during pharmaceutical development and manufacturing. The reference standard links the potency of dosages administered to the patient with those of original clinical studies. Therefore, the assignment of potency to biotherapeutic reference standards is vital for assuring the quality of medicines for patients. In this work, we propose a comprehensive roadmap for assigning potency to reference standards that is compliant with the two-tier system of standards as recommended in regulatory guidance. The roadmap includes statistical approaches for study design and acceptance criteria that are risk-based and phase-appropriate. It also provides mitigation approaches for potential assay bias.


Assuntos
Bioensaio , Projetos de Pesquisa , Humanos , Proteínas , Padrões de Referência
9.
Biologicals ; 36(6): 393-402, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18757212

RESUMO

An adventitious agent contamination occurred during a routine 9 CFR bovine viral screening test at BioReliance for an Eli Lilly Chinese Hamster Ovary (CHO) cell-derived Master Cell Bank (MCB) intended for biological production. Scientists from the sponsor (Eli Lilly and Company) and the testing service company (BioReliance) jointly conducted a systematic investigation in an attempt to determine the root cause of the contamination. Our investigation resulted in the identification of the viral nature of the contaminant. Subsequent experiments indicated that the viral contaminant was a non-enveloped and non-hemadsorbing virus. Transmission electron microscopy (TEM) revealed that the viral contaminant was 25-30 nm in size and morphologically resembled viruses of the family Picornaviridae. The contaminant virus was readily inactivated when exposed to acidic pH, suggesting that the viral contaminant was a member of rhinoviruses. Although incapable of infecting CHO cells, the viral contaminant replicated efficiently in Vero cell with a life cycle of approximately 16 h. Our investigation provided compelling data demonstrating that the viral contaminant did not originate from the MCB. Instead, it was introduced into the process during cell passaging and a possible entry point was proposed. We identified the viral contaminant as an equine rhinitis A virus using molecular cloning and DNA sequencing. Finally, our investigation led us to conclude that the source of the viral contaminant was the equine serum added to the cell growth medium in the 9 CFR bovine virus test.


Assuntos
Aphthovirus/metabolismo , Produtos Biológicos/normas , Tecnologia Farmacêutica/métodos , Animais , Produtos Biológicos/análise , Biotecnologia/métodos , Células CHO , Bovinos , Chlorocebus aethiops , Cricetinae , Cricetulus/metabolismo , Concentração de Íons de Hidrogênio , Microscopia Eletrônica de Transmissão , Picornaviridae/metabolismo , Fatores de Tempo , Células Vero
10.
Diabetes Care ; 40(5): 655-662, 2017 05.
Artigo em Inglês | MEDLINE | ID: mdl-28213374

RESUMO

OBJECTIVE: Hypoglycemia may exert proarrhythmogenic effects on the heart via sympathoadrenal stimulation and hypokalemia. Hypoglycemia-induced cardiac dysrhythmias are linked to the "dead-in-bed syndrome," a rare but devastating condition. We examined the effect of nocturnal and daytime clinical hypoglycemia on electrocardiogram (ECG) in young people with type 1 diabetes. RESEARCH DESIGN AND METHODS: Thirty-seven individuals with type 1 diabetes underwent 96 h of simultaneous ambulatory ECG and blinded continuous interstitial glucose monitoring (CGM) while symptomatic hypoglycemia was recorded. Frequency of arrhythmias, heart rate variability, and cardiac repolarization were measured during hypoglycemia and compared with time-matched euglycemia during night and day. RESULTS: A total of 2,395 h of simultaneous ECG and CGM recordings were obtained; 159 h were designated hypoglycemia and 1,355 h euglycemia. A median duration of nocturnal hypoglycemia of 60 min (interquartile range 40-135) was longer than daytime hypoglycemia of 44 min (30-70) (P = 0.020). Only 24.1% of nocturnal and 51.0% of daytime episodes were symptomatic. Bradycardia was more frequent during nocturnal hypoglycemia compared with matched euglycemia (incident rate ratio [IRR] 6.44 [95% CI 6.26, 6.63], P < 0.001). During daytime hypoglycemia, bradycardia was less frequent (IRR 0.023 [95% CI 0.002, 0.26], P = 0.002) and atrial ectopics more frequent (IRR 2.29 [95% CI 1.19, 4.39], P = 0.013). Prolonged QTc, T-peak to T-end interval duration, and decreased T-wave symmetry were detected during nocturnal and daytime hypoglycemia. CONCLUSIONS: Asymptomatic hypoglycemia was common. We identified differences in arrhythmic risk and cardiac repolarization during nocturnal versus daytime hypoglycemia in young adults with type 1 diabetes. Our data provide further evidence that hypoglycemia is proarrhythmogenic.


Assuntos
Arritmias Cardíacas/etiologia , Ritmo Circadiano/fisiologia , Diabetes Mellitus Tipo 1/fisiopatologia , Hipoglicemia/fisiopatologia , Adulto , Arritmias Cardíacas/fisiopatologia , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca/fisiologia , Humanos , Hipoglicemia/etiologia , Masculino , Fatores de Risco
11.
Nucleic Acids Res ; 31(4): 1282-91, 2003 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-12582248

RESUMO

Polyamides are a class of heterocyclic small molecules with the potential of controlling gene expression by binding to the minor groove of DNA in a sequence-specific manner. To evaluate the feasibility of this class of compounds as antiviral therapeutics, molecules were designed to essential sequence elements occurring numerous times in the HPV genome. This sequence element is bound by a virus-encoded transcription and replication factor E2, which binds to a 12 bp recognition site as a homodimeric protein. Here, we take advantage of polyamide:DNA and E2:DNA co-crystal structural information and advances in polyamide synthetic chemistry to design tandem hairpin polyamides that are capable of displacing the major groove-binding E2 homodimer from its DNA binding site. The binding of tandem hairpin polyamides and the E2 DNA binding protein to the DNA site is mutually exclusive even though the two ligands occupy opposite faces of the DNA double helix. We show with circular permutation studies that the tandem hairpin polyamide prevents the intrinsic bending of the E2 DNA site important for binding of the protein. Taken together, these results illustrate the feasibility of inhibiting the binding of homodimeric, major groove-binding transcription factors by altering the local DNA geometry using minor groove-binding tandem hairpin polyamides.


Assuntos
DNA Viral/metabolismo , Proteínas de Ligação a DNA , Nylons/metabolismo , Proteínas Oncogênicas Virais/metabolismo , Sítios de Ligação/genética , DNA Viral/química , Modelos Biológicos , Conformação de Ácido Nucleico , Nylons/química , Oligonucleotídeos/genética , Oligonucleotídeos/metabolismo , Proteínas Oncogênicas Virais/química , Papillomaviridae/genética , Papillomaviridae/metabolismo , Ligação Proteica
12.
F1000Res ; 4: 119, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-27785351

RESUMO

Amyotrophic lateral sclerosis (ALS) is a dreadful, devastating and incurable motor neuron disease. Aetiologically, it is a multigenic, multifactorial and multiorgan disease. Despite intense research, ALS pathology remains unexplained. Following extensive literature review, this paper posits a new integrative explanation. This framework proposes that ammonia neurotoxicity is a main player in ALS pathogenesis. According to this explanation, a combination of impaired ammonia removal- mainly because of impaired hepatic urea cycle dysfunction-and increased ammoniagenesis- mainly because of impaired glycolytic metabolism in fast twitch skeletal muscle-causes chronic hyperammonia in ALS. In the absence of neuroprotective calcium binding proteins (calbindin, calreticulin and parvalbumin), elevated ammonia-a neurotoxin-damages motor neurons. Ammonia-induced motor neuron damage occurs through multiple mechanisms such as macroautophagy-endolysosomal impairment, endoplasmic reticulum (ER) stress, CDK5 activation, oxidative/nitrosative stress, neuronal hyperexcitability and neuroinflammation. Furthermore, the regional pattern of calcium binding proteins' loss, owing to either ER stress and/or impaired oxidative metabolism, determines clinical variability of ALS. Most importantly, this new framework can be generalised to explain other neurodegenerative disorders such as Huntington's disease and Parkinsonism.

13.
MAbs ; 4(3): 310-8, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22531445

RESUMO

Humanized monoclonal antibodies (mAbs) are the fastest growing class of biological therapeutics that are being developed for various medical indications, and more than 30 mAbs are already approved and in the market place. Antibody-dependent cell-mediated cytotoxicity (ADCC) is an important biological function attributed to the mechanism of action of several therapeutic antibodies, particularly oncology targeting mAbs. The ADCC assay is a complicated and highly variable assay. Thus, the use of an ADCC assay as a lot release test or a stability test for clinical trial batches of mAbs has been a substantial challenge to install in quality control laboratories. We describe here the development and validation of an alternate approach, an ADCC-reporter gene assay that is based on the key attributes of the PBMC-based ADCC assay. We tested the biological relevance of this assay using an anti-CD20 based model and demonstrated that this ADCC-reporter assay correlated well with standard ADCC assays when induced with the drugable human isotypes [IgG1, IgG2, IgG4, IgG4S > P (S228P) and IgG4PAA (S228P, F234A, L235A)] and with IgG1 isotype variants with varying amounts of fucosylation. This data demonstrates that the ADCC-reporter gene assay has performance characteristics (accuracy, precision and robustness) to be used not only as a potency assay for lot release and stability testing for antibody therapeutics, but also as a key assay for the characterization and process development of therapeutic molecules.


Assuntos
Anticorpos Monoclonais Humanizados/imunologia , Citotoxicidade Celular Dependente de Anticorpos/genética , Testes Imunológicos de Citotoxicidade , Genes Reporter , Antígenos CD20/imunologia , Estudos de Viabilidade , Humanos , Leucócitos Mononucleares/imunologia , Variações Dependentes do Observador , Controle de Qualidade , Reprodutibilidade dos Testes
14.
Diabetes Res Clin Pract ; 94(1): 64-70, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21715038

RESUMO

BACKGROUND: Abnormally elevated alanine aminotransferase (ALT) of nonspecific causes is a common outpatient problem. Without considering ethnicity, several studies had suggested that it was associated with insulin resistance (IR). OBJECTIVE: To investigate whether nonspecific elevated ALT in Taiwanese population could reflect a likely underlying IR and was associated with impaired fasting glucose or type 2 diabetes mellitus (IFG/T2DM). METHODS: The health examination profiles of 1313 Taiwanese were investigated cross-sectionally. The prevalence and odds ratios (ORs) for IFG/T2DM and metabolic abnormalities in relation to elevated ALT were analyzed. RESULTS: Subjects with metabolic syndrome (MS) all had IFG/T2DM. The elevated ALT significantly correlated with MS and IFG/T2DM (i.e., 19.9-29.2% vs. 7.8% for MS, and 27.0-31.5% vs. 16.1% for IFG/T2DM). However, after excluding MS and adjustment for age and sex, the elevated ALT alone was not consistently associated with IFG/T2DM (36 < ALT ≤ 80 IU/L with OR 0.97, 95% CI 0.58-1.61; 80 < ALT ≤ 120 IU/L with OR 0.55, 95% CI 0.13-2.37; none with ALT > 120 had IFG). CONCLUSIONS: In a cross-sectional analysis of Taiwanese industrial employees, elevated ALT associated with MS, but in subjects who did not meet MS criteria, elevated ALT by itself did not associate with IFG/T2DM.


Assuntos
Alanina Transaminase/metabolismo , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/enzimologia , Jejum/sangue , Síndrome Metabólica/sangue , Síndrome Metabólica/enzimologia , Adulto , Idoso , Glicemia/metabolismo , Estudos Transversais , Feminino , Humanos , Modelos Logísticos , Masculino , Pessoa de Meia-Idade
15.
Nat Rev Drug Discov ; 10(2): 101-11, 2011 02.
Artigo em Inglês | MEDLINE | ID: mdl-21283105

RESUMO

The Fc (crystallizable fragment) region of therapeutic antibodies can have an important role in their safety and efficacy. Although much is known about the structure-activity relationship of antibodies and the factors that influence Fc effector functions, a process has not yet been defined to clearly delineate how Fc functionality should be assessed and controlled during antibody development and manufacturing. In this article, we summarize the current knowledge of antibody Fc functionality, provide a strategy for assessing the effector functions of different classes of therapeutic antibodies (including Fc fusion proteins) and propose a path for routine testing and controls for manufacturers of antibody products.


Assuntos
Anticorpos/química , Anticorpos/uso terapêutico , Fragmentos Fc das Imunoglobulinas/química , Fragmentos Fc das Imunoglobulinas/uso terapêutico , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/uso terapêutico , Cristalização , Humanos , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/imunologia , Proteínas Recombinantes de Fusão/uso terapêutico
16.
Nano Lett ; 8(8): 2176-9, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18642960

RESUMO

Optical anisotropy in single-walled carbon nanotube thin film networks is reported. We obtain the real and imaginary parts of the in-(parallel) and out-of-plane (perpendicular) complex dielectric functions of the single-walled carbon nanotube (SWNT) thin films by combining transmission measurements at several incidence angles with spectroscopic ellipsometry data on different substrates. In sparse networks, the two components of the real part of the complex dielectric constant (epsilon1 parallel and epsilon1 perpendicular) were found to differ by 1.5 at 2.25 eV photon energy. The resulting angular dependence (from 0 to 70 degrees incidence angles) of transmittance is reflected in the conversion efficiency of organic solar cells utilizing SWNT thin films as the hole conducting electrodes. Our results indicate that, in addition to the transparency and sheet resistance, factors such as the optical anisotropy must be considered for optical devices incorporating SWNT networks.

17.
Mol Biol Cell ; 19(8): 3308-22, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18508913

RESUMO

Brahma (BRM) and Brahma-related gene 1 (BRG1) are the ATP-dependent catalytic subunits of the SWI/SNF family of chromatin-remodeling complexes. These complexes are involved in essential processes such as cell cycle, growth, differentiation, and cancer. Using imaging approaches in a cell line that harbors tandem repeats of stably integrated copies of the steroid responsive MMTV-LTR (mouse mammary tumor virus-long terminal repeat), we show that BRG1 and BRM are recruited to the MMTV promoter in a hormone-dependent manner. The recruitment of BRG1 and BRM resulted in chromatin remodeling and decondensation of the MMTV repeat as demonstrated by an increase in the restriction enzyme accessibility and in the size of DNA fluorescence in situ hybridization (FISH) signals. This chromatin remodeling event was concomitant with an increased occupancy of RNA polymerase II and transcriptional activation at the MMTV promoter. The expression of ATPase-deficient forms of BRG1 (BRG1-K-R) or BRM (BRM-K-R) inhibited the remodeling of local and higher order MMTV chromatin structure and resulted in the attenuation of transcription. In vivo photobleaching experiments provided direct evidence that BRG1, BRG1-K-R, and BRM chromatin-remodeling complexes have distinct kinetic properties on the MMTV array, and they dynamically associate with and dissociate from MMTV chromatin in a manner dependent on hormone and a functional ATPase domain. Our data provide a kinetic and mechanistic basis for the BRG1 and BRM chromatin-remodeling complexes in regulating gene expression at a steroid hormone inducible promoter.


Assuntos
Cromatina/química , DNA Helicases/metabolismo , Proteínas Nucleares/metabolismo , Regiões Promotoras Genéticas , Receptores de Glucocorticoides/metabolismo , Fatores de Transcrição/metabolismo , Trifosfato de Adenosina/química , Animais , Linhagem Celular Tumoral , Cromatina/metabolismo , Hidrólise , Hibridização in Situ Fluorescente , Cinética , Vírus do Tumor Mamário do Camundongo/metabolismo , Camundongos , Modelos Biológicos , RNA Polimerase II/química
18.
Rapid Commun Mass Spectrom ; 22(4): 526-32, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18215004

RESUMO

Selected ion flow tube mass spectrometry (SIFT-MS) has been used to carry out a pilot parallel study on five volunteers to determine changes occurring in several trace compounds present in exhaled breath and emitted from skin into a collection bag surrounding part of the arm, before and after ingesting 75 g of glucose in the fasting state. SIFT-MS enabled real-time quantification of ammonia, methanol, ethanol, propanol, formaldehyde, acetaldehyde, isoprene and acetone. Following glucose ingestion, blood glucose and trace compound levels were measured every 30 min for 2 h. All the above compounds, except formaldehyde, were detected at the expected levels in exhaled breath of all volunteers; all the above compounds, except isoprene, were detected in the collection bag. Ammonia, methanol and ethanol were present at lower levels in the bag than in the breath. The aldehydes were present at higher levels in the bag than in breath. The blood glucose increased to a peak about 1 h post-ingestion, but this change was not obviously correlated with temporal changes in any of the compounds in breath or emitted by skin, except for acetone. The decrease in breath acetone was closely mirrored by skin-emitted acetone in three volunteers. Breath and skin acetone also clearly change with blood glucose and further work may ultimately enable inferences to be drawn of the blood glucose concentration from skin or breath measurements in type 1 diabetes.


Assuntos
Artefatos , Análise Química do Sangue/métodos , Testes Respiratórios/métodos , Cromatografia Líquida de Alta Pressão/métodos , Dipiridamol/sangue , Análise de Injeção de Fluxo/métodos , Compostos Orgânicos/análise , Pele/metabolismo , Espectrometria de Massas por Ionização por Electrospray/métodos , Testes Respiratórios/instrumentação , Análise de Injeção de Fluxo/instrumentação , Gases/sangue , Humanos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Espectrometria de Massas por Ionização por Electrospray/instrumentação , Volatilização
19.
Mol Cell ; 22(5): 669-79, 2006 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-16762839

RESUMO

Although histone deacetylases (HDACs) are generally viewed as corepressors, we show that HDAC1 serves as a coactivator for the glucocorticoid receptor (GR). Furthermore, a subfraction of cellular HDAC1 is acetylated after association with the GR, and this acetylation event correlates with a decrease in promoter activity. HDAC1 in repressed chromatin is highly acetylated, while the deacetylase found on transcriptionally active chromatin manifests a low level of acetylation. Acetylation of purified HDAC1 inactivates its deacetylase activity, and mutation of the critical acetylation sites abrogates HDAC1 function in vivo. We propose that hormone activation of the receptor leads to progressive acetylation of HDAC1 in vivo, which in turn inhibits the deacetylase activity of the enzyme and prevents a deacetylation event that is required for promoter activation. These findings indicate that HDAC1 is required for the induction of some genes by the GR, and this activator function is dynamically modulated by acetylation.


Assuntos
Histona Desacetilases/metabolismo , Receptores de Glucocorticoides/metabolismo , Ativação Transcricional , Acetilação , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas de Ciclo Celular/imunologia , Proteínas de Ciclo Celular/metabolismo , Cromatina/metabolismo , Regulação para Baixo , Células HeLa , Histona Acetiltransferases/imunologia , Histona Acetiltransferases/metabolismo , Histona Desacetilase 1 , Histona Desacetilases/genética , Humanos , Ligantes , Vírus do Tumor Mamário do Camundongo/metabolismo , Camundongos , Modelos Genéticos , Dados de Sequência Molecular , Células NIH 3T3 , Regiões Promotoras Genéticas , Fatores de Transcrição/imunologia , Fatores de Transcrição/metabolismo , Células Tumorais Cultivadas , Fatores de Transcrição de p300-CBP
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