RESUMO
BACKGROUND: Cell entry of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) depends on binding of the viral spike (S) proteins to angiotensin-converting enzyme 2 and on S protein priming by TMPRSS2. Inhibition of TMPRSS2 may work to block or decrease the severity of SARS-CoV-2 infections. Intriguingly, TMPRSS2 is an androgen-regulated gene that is up-regulated in prostate cancer where it supports tumor progression and is involved in a frequent genetic translocation with the ERG gene. First- or second-generation androgen-deprivation therapies (ADTs) decrease the levels of TMPRSS2. Here we put forward the hypothesis that ADTs may protect patients affected by prostate cancer from SARS-CoV-2 infections. MATERIALS AND METHODS: We extracted data regarding 9280 patients (4532 males) with laboratory-confirmed SARS-CoV-2 infection from 68 hospitals in Veneto, one of the Italian regions that was most affected by the coronavirus disease 2019 (COVID-19) pandemic. The parameters used for each COVID-19-positive patient were sex, hospitalization, admission to intensive care unit, death, tumor diagnosis, prostate cancer diagnosis, and ADT. RESULTS: There were evaluable 9280 SARS-CoV-2-positive patients in Veneto on 1 April 2020. Overall, males developed more severe complications, were more frequently hospitalized, and had a worse clinical outcome than females. Considering only the Veneto male population (2.4 million men), 0.2% and 0.3% of non-cancer and cancer patients, respectively, tested positive for SARS-CoV-2. Comparing the total number of SARS-CoV-2-positive cases, prostate cancer patients receiving ADT had a significantly lower risk of SARS-CoV-2 infection compared with patients who did not receive ADT (OR 4.05; 95% CI 1.55-10.59). A greater difference was found comparing prostate cancer patients receiving ADT with patients with any other type of cancer (OR 4.86; 95% CI 1.88-12.56). CONCLUSION: Our data suggest that cancer patients have an increased risk of SARS-CoV-2 infections compared with non-cancer patients. However, prostate cancer patients receiving ADT appear to be partially protected from SARS-CoV-2 infections.
Assuntos
Antagonistas de Androgênios/uso terapêutico , Betacoronavirus , Infecções por Coronavirus/prevenção & controle , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Vigilância da População , Neoplasias da Próstata/tratamento farmacológico , Idoso , Idoso de 80 Anos ou mais , COVID-19 , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Humanos , Itália/epidemiologia , Masculino , Pessoa de Meia-Idade , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Neoplasias da Próstata/diagnóstico , Neoplasias da Próstata/epidemiologia , Fatores de Risco , SARS-CoV-2RESUMO
The competitive wetting of oil and aqueous electrolytes on solid surfaces depends strongly on the surface charge of the solid-water and the water-oil interface. This charge density is generally not known a priori but changes as ions adsorb or desorb from or to the interfaces, depending on the composition of the fluid and the thickness of thin films of the aqueous phase that frequently arise on hydrophilic surfaces, such as minerals. We analyze the wettability of such systems by coupling standard Derjaguin-Landau-Verwey-Overbeek theory to a linearized charge regulation model. The latter is found to play an important role. By linearizing electrostatic interactions as well, we obtain a fully analytic description of transitions between different wetting scenarios as a function of the surface potentials at infinite separation and the charge regulation parameters of the two interfaces. Depending on the specific values of the regulation parameters, charge regulation is found to extend the parameter range of partial wetting and complete wetting at the expense of pseudopartial wetting and metastable wetting configurations, respectively. A specific implementation of the model is discussed for mica-water-alkane systems that was investigated in recent experiments.
RESUMO
Exploitation of the biologic activity of neurotrophins is desirable for medical purposes, but their protein nature intrinsically bears adverse pharmacokinetic properties. Here, we report synthesis and biologic characterization of a novel class of low molecular weight, non-peptidic compounds with NGF (nerve growth factor)-mimetic properties. MT2, a representative compound, bound to Trk (tropomyosin kinase receptor)A chain on NGF-sensitive cells, as well as in cell-free assays, at nanomolar concentrations and induced TrkA autophosphorylation and receptor-mediated internalization. MT2 binding involved at least two amino-acid residues within TrkA molecule. Like NGF, MT2 increased phosphorylation of extracellular signal-regulated kinase 1/2 and Akt proteins and production of MKP-1 phosphatase (dual specificity phosphatase 1), modulated p38 mitogen-activated protein kinase activation,sustained survival of serum-starved PC12 or RDG cells, and promoted their differentiation. However, the intensity of such responses was heterogenous, as the ability of maintaining survival was equally possessed by NGF and MT2, whereas the induction of differentiation was expressed at definitely lower levels by the mimetic. Analysis of TrkA autophosphorylation patterns induced by MT2 revealed a strong tyrosine (Tyr)490 and a limited Tyr785 and Tyr674/675 activation, findings coherent with the observed functional divarication. Consistently, in an NGF-deprived rat hippocampal neuronal model of Alzheimer Disease, MT2 could correct the biochemical abnormalities and sustain cell survival. Thus, NGF mimetics may reveal interesting investigational tools in neurobiology, as well as promising drug candidates.
Assuntos
Azepinas/farmacologia , Fator de Crescimento Neural/farmacologia , Receptor trkA/agonistas , Animais , Azepinas/química , Sítios de Ligação , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Peso Molecular , Células NIH 3T3 , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Células PC12 , Fosforilação , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Receptor trkA/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Exploitation of the biologic activity of neurotrophins is desirable for medical purposes, but their protein nature intrinsically bears adverse pharmacokinetic properties. Here, we report synthesis and biologic characterization of a novel class of low molecular weight, non-peptidic compounds with NGF (nerve growth factor)-mimetic properties. MT2, a representative compound, bound to Trk (tropomyosin kinase receptor)A chain on NGF-sensitive cells, as well as in cell-free assays, at nanomolar concentrations and induced TrkA autophosphorylation and receptor-mediated internalization. MT2 binding involved at least two amino-acid residues within TrkA molecule. Like NGF, MT2 increased phosphorylation of extracellular signal-regulated kinase1/2 and Akt proteins and production of MKP-1 phosphatase (dual specificity phosphatase 1), modulated p38 mitogen-activated protein kinase activation, sustained survival of serum-starved PC12 or RDG cells, and promoted their differentiation. However, the intensity of such responses was heterogenous, as the ability of maintaining survival was equally possessed by NGF and MT2, whereas the induction of differentiation was expressed at definitely lower levels by the mimetic. Analysis of TrkA autophosphorylation patterns induced by MT2 revealed a strong tyrosine (Tyr)490 and a limited Tyr785 and Tyr674/675 activation, findings coherent with the observed functional divarication. Consistently, in an NGF-deprived rat hippocampal neuronal model of Alzheimer Disease, MT2 could correct the biochemical abnormalities and sustain cell survival. Thus, NGF mimetics may reveal interesting investigational tools in neurobiology, as well as promising drug candidates.
Assuntos
Azepinas/farmacologia , Fator de Crescimento Neural/farmacologia , Receptor trkA/agonistas , Animais , Azepinas/química , Sítios de Ligação , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Hipocampo/citologia , Hipocampo/metabolismo , Humanos , Camundongos , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Peso Molecular , Células NIH 3T3 , Fator de Crescimento Neural/genética , Fator de Crescimento Neural/metabolismo , Células PC12 , Fosforilação , Estrutura Terciária de Proteína , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Receptor trkA/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/farmacologia , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismoRESUMO
Hemodialysis was born in 1945 to treat acute renal failure, and it has progressively become a rescue therapy for patients with chronic kidney disease (CKD) stage 5, otherwise doomed to death. During the years, technological innovations have led to improved dialytic tolerance, making possible to extend the treatment to a greater number of subjects. Low- and high-flux bicarbonate dialysis are nowadays the most frequent hemodialysis techniques; hemodiafiltration with different modalities, short daily and overnight hemo-dialysis are also widespread, each of them with peculiar characteristics. A recent randomized controlled clinical trial has identified high-flux hemodialysis as the best treatment for patients with low serum levels of albumin and for diabetics in comparison to low flux dialysis. Apart from the treatment of end-stage renal disease (ESRD), hemodialysis has new and important applications, including heart failure treatment and multiple myeloma. The need to provide hemodialysis patients a better quality of life has increased the interest in developing new techniques, such as the wearable artificial kidney, although still in initial clinical development. During the last 60 years, we have seen an exciting evolution in the field of hemodialysis, which has led to important changes in the outcome of ESRD patients. The preclinical and clinical hard work ongoing in earlier stages of CKD should be able to obtain further relevant improvements and maybe avoid the need of hemodialysis itself.
Assuntos
Hemodiafiltração/métodos , Hemodiafiltração/tendências , Falência Renal Crônica/terapia , Insuficiência Cardíaca/terapia , Humanos , Mieloma Múltiplo/terapia , Qualidade de Vida , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
AIM: To investigate, in a phase II prospective study, the efficacy of partial breast irradiation administered with high-dose-rate brachytherapy. METHODS: After conservative surgery 80 patients with low-risk early-stage breast cancer received 4 Gy twice a day for 4 days (total dose 32 Gy). Catheter implantation was performed during surgery in 15 cases and postoperatively, at a median of 8 weeks from surgery, in 65 patients. Adjuvant therapy was chemotherapy (8) and/or hormone therapy (61). RESULTS: Cosmetic results were good/excellent in 79 patients. Perioperative toxicity was very low. Acute skin toxicity developed in seven cases (six G1; one G2); late G3 cutaneous toxicity in one patient and late subcutaneous toxicity in five (three G1; two G2). Grade 1 teleangiectasia occurred in eight patients and grade 2 in one. Fat necrosis was symptomatic in one patient and asymptomatic in five. Only one patient presented pain after brachytherapy. A significantly (p=0.001) higher frequency of late toxicity was observed in patients implanted during surgery, the group, which included the only patient with a fair cosmetic result. No local or regional relapses have occurred to date. The median follow-up was 30 months (range 3-52). CONCLUSION: This strategy is a viable option in selected patients with early-stage breast cancer as it is feasible, reproducible and associated with very low perioperative and acute toxicity. The low incidence of late side effects will probably change as follow-up lengthens.
Assuntos
Braquiterapia/métodos , Neoplasias da Mama/radioterapia , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/diagnóstico por imagem , Neoplasias da Mama/patologia , Relação Dose-Resposta à Radiação , Feminino , Seguimentos , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Estudos Prospectivos , Planejamento da Radioterapia Assistida por Computador/métodos , Fatores de Tempo , Tomografia Computadorizada por Raios X , Resultado do TratamentoRESUMO
BACKGROUND: The ability of negative expiratory pressure (NEP) technique to differentiate between awake snorers with and without obstructive sleep apnea-hypopnea (OSAH) was investigated. METHODS: Forty-eight subjects with sleep disordered breathing (SDB) and 7 healthy subjects, as non-snorer controls, underwent the NEP application of -5 and -7 cmH2O in the seated and supine position during wakefulness, after performing a sleep study. The upper airway collapsibility was assessed by computing the volume exhaled during the first 0.5 sec. (V,NEP0.5) and 1 sec. (V,NEP1) following the NEP start. RESULTS: Patients with severe (AHI > or = 30) (n = 19) and mild-to-moderate (AHI <30 and >5) (n = 15) OSAH had lower V,NEP0.5 (340 +/- 88 ml) as compared to snorers (AHI < or = 5) (n = 14) (427 +/- 101 ml; p < 0.01) and controls (n = 7) (492 +/- 69 ml; p < 0.001) in the supine position with NEP -5 cmH2O. Less significant differences among the different groups were observed for V,NEP0.5 in the seated position with NEP -5 cmH2O and in both positions with NEP -7 cmH2O (only OSAH patients vs controls, p < 0.001). Similar results were obtained for V,NEP1 in either position by using both NEP -5 cmH2O and -7 cmH2O. In spite of this, a substantial overlapping of V,NEP0.5 and V,NEP1 between snorers and OSAH patients did not allow to identify a reliable diagnostic cut-off level. An inverse correlation with AHI was found for V,NEP0.5 in the supine position with NEP -5 cmH2O (rs = -0.46, p < 0.05) in severe OSAH patients. CONCLUSION: The awake OSAH patients exhibit values of V,NEP0.5 and V,NEP1 lesser than those of awake snorers. The NEP technique, however, appears to have a limited usefulness as clinical tool for routine screening of the OSAH patients during wakefulness.
Assuntos
Expiração/fisiologia , Pulmão/fisiopatologia , Apneia Obstrutiva do Sono/diagnóstico , Apneia Obstrutiva do Sono/fisiopatologia , Ronco/fisiopatologia , Capacidade Vital/fisiologia , Índice de Massa Corporal , Estudos de Casos e Controles , Estado de Consciência/fisiologia , Humanos , Masculino , Programas de Rastreamento , Pico do Fluxo Expiratório/fisiologia , Polissonografia , Postura/fisiologia , Estudos Prospectivos , Respiradores de Pressão NegativaRESUMO
We report the detection and molecular characterization of a rotavirus strain, 10733, isolated from the feces of a buffalo calf affected with diarrhea in Italy. Strain 10733 was classified as a P[3] rotavirus, as the VP8* trypsin cleavage product of the VP4 protein revealed a high amino acid identity (96.2%) with that of rhesus rotavirus strain RRV (P5B[3]), used as the recipient virus in the human-simian reassortant vaccine. Analysis of the VP7 gene product revealed that strain 10733 possessed G6 serotype specificity, a type common in ruminants, with an amino acid identity to G6 rotavirus strains ranging from 88 to 98%, to Venezuelan bovine strain BRV033, and Hungarian human strain Hun4. Phylogenetic analysis based on the VP7 gene of G6 rotaviruses identified at least four lineages and an apparent linkage between each lineage and the VP4 specificity, suggesting the occurrence of repeated interspecies transmissions and genetic reassortment events between ruminant and human rotaviruses. Moreover, strain 10733 displayed a bovine-like NSP4 and NSP5/6 and a subgroup I VP6 specificity, as well as a long electropherotype pattern. The detection of the rare P[3] genotype in ruminants provides additional evidence for the wide genetic and antigenic diversity of group A rotaviruses.
Assuntos
Antígenos Virais , Proteínas do Capsídeo/genética , Genes Virais , Rotavirus/genética , Rotavirus/isolamento & purificação , Proteínas não Estruturais Virais/genética , Proteínas Estruturais Virais/genética , Alelos , Sequência de Aminoácidos , Animais , Aves , Bovinos , Doenças dos Bovinos/virologia , Diarreia/veterinária , Diarreia/virologia , Fezes/virologia , Cavalos , Humanos , Macaca mulatta/virologia , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase/métodos , Rotavirus/classificação , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , SuínosRESUMO
Cyclin-dependent kinase 1 (CDK1) is an interesting target for potential anticancer drugs, and its three-dimensional (3D) structure is presently unknown. The purpose of this work was to build a 3D model of CDK1, which could be used in drug design studies. The protein 3D structure was homology modeled, based on the known crystal structure of CDK2, and new nonbonded parameters for the Mg(2+) coordination complex were developed by means of ab initio quantum chemical calculations. These parameters were both obtained and validated using the CDK2 structure as reference, and then they were used for the refinement of the CDK1 model. The resulting CDK1 structure was satisfactory and stable at room temperature, as shown by the molecular dynamics simulations carried out over a 1-ns time interval on the entire protein. A number of representative kinases in the active and inactive form, including the inactive CDK1 modeled in this work, were compared. The results illustrate the conformational variability of the activation loop of the inactive form of the kinases and suggest a way for selectively targeting the single CDKs.
Assuntos
Proteína Quinase CDC2/química , Modelos Moleculares , Sequência de Aminoácidos , Simulação por Computador , Magnésio , Dados de Sequência Molecular , Fosfotransferases/química , Conformação Proteica , Homologia de Sequência de Aminoácidos , Temperatura , TermodinâmicaRESUMO
Fusion proteins were constructed between the delta opioid receptor and forms of the alpha subunit of G(i1) in which cysteine(351) was mutated to a range of amino acids. GDP reduced the binding of the agonist [(3)H]DADLE but not the antagonist [(3)H]naltrindole to both the receptor alone and all the delta opioid receptor-Cys(351)XaaG(i1)alpha fusion proteins. For the fusion proteins the pEC(50) for GDP was strongly correlated with the n-octanol/H(2)O partition co-efficient of G protein residue(351). Fusion proteins in which this residue was either isoleucine or glycine had similar observed binding kinetics for [(3)H]DADLE. However, the rate of dissociation of [(3)H]DADLE was substantially greater for the glycine-containing fusion protein than that containing isoleucine, indicating that more hydrophobic residues imbued greater stability to the agonist-receptor-G protein ternary complex. This resulted in a higher affinity of binding of [(3)H]DADLE to the fusion protein containing isoleucine(351). In expectation with the binding data, maximal DADLE-stimulated GTP hydrolysis by the isoleucine(351)-containing fusion protein was two-fold greater and the potency of DADLE seven-fold higher than for the version containing glycine. These results demonstrate that the stability of the ternary complex between delta opioid receptor, G(i1)alpha and an agonist (but not antagonist) ligand is dependent upon the nature of residue(351) of the G protein and that this determines the effectiveness of information flow from the receptor to the G protein.
Assuntos
Proteínas de Ligação ao GTP/genética , Proteínas Heterotriméricas de Ligação ao GTP/genética , Naltrexona/análogos & derivados , Receptores sigma/agonistas , Membrana Celular/efeitos dos fármacos , Células Cultivadas , Leucina Encefalina-2-Alanina/farmacologia , GTP Fosfo-Hidrolases/metabolismo , Humanos , Cinética , Naltrexona/metabolismo , Antagonistas de Entorpecentes/farmacologia , Oligonucleotídeos Antissenso/farmacologia , Receptores sigma/genética , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/farmacologia , TransfecçãoRESUMO
The molecular organization of purely aromatic, polyphenyl carboxylic acids, as Langmuir monolayers at the air/water interface, has been investigated by means of surface pressure and electric surface potential measurements upon film compression. The monolayer characteristics of the basic compound, a symmetrical triphenylbenzene (5'-phenyl-m-terphenyl) ring with a carboxylic group at the 4 position (namely 5'-phenyl-1,1' : 3',1"-terphenyl-4-carboxylic acid), are compared with those of its derivatives containing hydrophilic (nitro) or hydrophobic (phenyl) substituents. The nature of the substituent as well as its position (2' or 4') has a profound influence on the monolayer properties. The results are discussed in view of molecular orientation deduced from values of effective dipole moments. Copyright 2001 Academic Press.
RESUMO
Aromatase (P450arom) is a target of pharmacological interest for the treatment of breast cancer. In this paper, we report the design, synthesis, and in vitro biological evaluation of a series of new (di)benzopyranone-based inhibitors of this enzyme. The design of the new compounds was guided by a CoMFA model previously developed for a series of nonsteroidal aromatase inhibitors. Both the chromone and the xanthone nuclei were taken as molecular skeletons, and the functions supposed to be critical for binding to the aromatase active site - a heterocyclic ring (imidazole or 1,3,4-triazole) linked to the aromatic moiety by a methylene unit and an H-bond accepting function (CN, NO(2), Br) located on the aromatic ring at a suitable distance from the heterocyclic nitrogen carrying the lone pair--were attached to them. The chromone, xanthone, and flavone derivatives were prepared by conventional synthetic methods from the appropriate methyl analogues. Aromatase inhibitory activities were determined by the method of Thompson and Siiteri, using human placental microsomes and [1 beta,2 beta-(3)H]testosterone as the labeled substrate. All the compounds were also tested on 17 alpha-hydroxylase/C17,20-lyase (P450 17), an enzyme of therapeutic interest for the treatment of prostatic diseases. The goal to find new potent inhibitors of aromatase was reached with the xanthone derivatives 22d,e (IC(50) values 43 and 40 nM, respectively), which exceeded the potency of the known reference drug fadrozole and also showed high selectivity with respect to P450 17. Moreover, compounds 22g-i based on the same xanthonic nucleus showed fairly high potency as P450 17 inhibitors (IC(50) values 220, 130, and 42 nM, respectively). Thus, they might be new leads for the development of drug candidates for androgen-dependent diseases.
Assuntos
Inibidores da Aromatase , Cromonas/síntese química , Inibidores Enzimáticos/síntese química , Esteroide 17-alfa-Hidroxilase/antagonistas & inibidores , Xantenos/síntese química , Xantonas , Cromonas/química , Cromonas/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Técnicas In Vitro , Masculino , Microssomos/efeitos dos fármacos , Microssomos/enzimologia , Modelos Moleculares , Placenta/ultraestrutura , Relação Estrutura-Atividade , Testículo/ultraestrutura , Xantenos/química , Xantenos/farmacologiaRESUMO
Agonist-stimulated high affinity GTPase activity of fusion proteins between the alpha(2A)-adrenoreceptor and the alpha subunits of forms of the G proteins G(i1), G(i2), G(i3), and G(o1), modified to render them insensitive to the action of pertussis toxin, was measured following transient expression in COS-7 cells. Addition of a recombinant regulator of G protein signaling protein, RGS4, did not significantly affect basal GTPase activity nor agonist stimulation of the fusion proteins containing Galpha(i1) and Galpha(i3) but markedly enhanced agonist-stimulation of the proteins containing Galpha(i2) and Galpha(o1.) The effect of RGS4 on the alpha(2A)-adrenoreceptor-Galpha(o1) fusion protein was concentration-dependent with EC(50) of 30 +/- 3 nm and the potency of the receptor agonist UK14304 was reduced 3-fold by 100 nm RGS4. Equivalent reconstitution with Asn(88)-Ser RGS4 failed to enhance agonist function on the alpha(2A)-adrenoreceptor-Galpha(o1) or alpha(2A)-adrenoreceptor-Galpha(i2) fusion proteins. Enzyme kinetic analysis of the GTPase activity of the alpha(2A)-adrenoreceptor-Galpha(o1) and alpha(2A)-adrenoreceptor-Galpha(i2) fusion proteins demonstrated that RGS4 both substantially increased GTPase V(max) and significantly increased K(m) of the fusion proteins for GTP. The increase in K(m) for GTP was dependent upon RGS4 amount and is consistent with previously proposed mechanisms of RGS function. Agonist-stimulated GTPase turnover number in the presence of 100 nm RGS4 was substantially higher for alpha(2A)-adrenoreceptor-Galpha(o1) than for alpha(2A)-adrenoreceptor-Galpha(i2). These studies demonstrate that although RGS4 has been described as a generic stimulator of the GTPase activity of G(i)-family G proteins, selectivity of this interaction and quantitative variation in its function can be monitored in the presence of receptor activation of the G proteins.
Assuntos
Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas RGS/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Agonistas de Receptores Adrenérgicos alfa 2 , Agonistas alfa-Adrenérgicos/farmacologia , Animais , Tartarato de Brimonidina , Subunidade alfa Gi2 de Proteína de Ligação ao GTP , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP , Proteínas Heterotriméricas de Ligação ao GTP/genética , Cinética , Mutação , Proteínas Proto-Oncogênicas/genética , Quinoxalinas/farmacologia , Proteínas RGS/genética , Receptores Adrenérgicos alfa 2/genética , Proteínas Recombinantes de Fusão/metabolismo , SuínosRESUMO
Compounds containing a 2-indolinone moiety linked to imidazothiazole and indole fragments were studied as cyclin-dependent kinase inhibitors. The activity of all the new derivatives was tested in vitro against CDK1/cyclinB and the selectivity towards two other kinases was determined for the most promising compounds. The binding mode of one representative compound was investigated by means of a three-dimensional model of the inhibitor-CDK1 complex. The work allowed us to identify (2-chloroindolyl)methylene-2-indolinone as a new lead of a class of CDK1/cyclinB inhibitors, whose potency can be improved by the introduction of suitable variations on the basic molecular skeleton.
Assuntos
Proteína Quinase CDC2/antagonistas & inibidores , Ciclina B/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Indóis/farmacologia , Sítios de Ligação , Proteína Quinase CDC2/química , Proteína Quinase CDC2/metabolismo , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Indóis/síntese química , Indóis/química , Modelos MolecularesRESUMO
There is a general recognition of the role of low birthweight (LBW) as a major determinant of infant mortality rates. Since the rate of LBW has been increasing over the past fifteen years in Japan, we decided to ascertain the risk factors related to it, and also to verify whether or not maternal leisure-time physical activities including sports activities, before pregnancy and during gestation, affected the rate of LBW babies. In our study of the 2,682 questionnaires delivered within a year to the Municipal Health Centers of the three cities chosen for this study, 1,714 questionnaires were analyzed. The results in a univariate analysis showed that maternal height, pre-pregnancy weight, length of gestation, smoking, hospitalization before the 37th week of gestation, a history of LBW, and occupational activities were significantly associated with LBW. In logistic regression analyses, mothers of smaller stature, less pre-pregnancy weight, less length of gestation and mothers who were, furthermore, hospitalized before the 37th week of gestation, smoked, had previously delivered a LBW baby or had experienced stressful events during pregnancy were more likely to have LBW babies. The results showed that maternal leisure-time physical activities before and/or during pregnancy had no bearing on the delivery of a LBW baby.
RESUMO
WB 4101 (1)-related benzodioxanes were synthesized by replacing the ethylene chain separating the amine and the phenoxy units of 1 with a cyclopentanol moiety, a feature of 6, 7-dihydro-5-[[(cis-2-hydroxy-trans-3-phenoxycyclopentyl)amino]meth yl] -2-methylbenzo[b]thiophen-4(5H)-one that was reported to display an intriguing selectivity profile at alpha(1)-adrenoreceptors. This synthesis strategy led to 4 out of 16 possible stereoisomers, which were isolated in the case of (-)-3, (+)-3, (-)-4, and (+)-4 and whose absolute configuration was assigned using a chiral building block for the synthesis of (-)-3 starting from (+)-(2R)-2, 3-dihydro-1,4-benzodioxine-2-carboxylic acid ((+)-9) and (1S,2S, 5S)-2-amino-5-phenoxycyclopentan-1-ol ((+)-10). The aim of this project was to further investigate whether it is possible to differentiate between these compounds with respect to their affinity for alpha(1)-adrenoreceptor subtypes and the affinity for 5-HT(1A) receptors, as 1 binds with high affinity at both receptor systems. The biological profiles of reported compounds at alpha(1)-adrenoreceptor subtypes were assessed by functional experiments in isolated rat vas deferens (alpha(1A)), spleen (alpha(1B)), and aorta (alpha(1D)) and by binding assays in CHO and HeLa cells membranes expressing the human cloned alpha(1)-adrenoreceptor subtypes and 5-HT(1A) receptors, respectively. Furthermore, the functional activity of (-)-3, (+)-3, (-)-4, and (+)-4 toward 5-HT(1A) receptors was evaluated by determining the induced stimulation of [(35)S]GTPgammaS binding in cell membranes from HeLa cells transfected with human cloned 5-HT(1A) receptors. The configuration of the cyclopentane unit determined the affinity profile: a 1R configuration, as in (+)-3 and (-)-4, conferred higher affinity at alpha(1)-adrenoreceptors, whereas a 1S configuration, as in (-)-3 and (+)-4, produced higher affinity for 5-HT(1A) receptors. For the enantiomers (+)-4 and (-)-4 also a remarkable selectivity was achieved. Functionally, the stereoisomers displayed a similar alpha(1)-selectivity profile, that is alpha(1D) > alpha(1B) > alpha(1A), which is different from that exhibited by the reference compound 1. The epimers (-)-3 and (+)-4 proved to be agonists at the 5-HT(1A) receptors, with a potency comparable to that of 5-hydroxytryptamine.
Assuntos
Dioxanos/síntese química , Receptores Adrenérgicos alfa 1/metabolismo , Receptores de Serotonina/metabolismo , Agonistas alfa-Adrenérgicos/síntese química , Agonistas alfa-Adrenérgicos/química , Agonistas alfa-Adrenérgicos/metabolismo , Agonistas alfa-Adrenérgicos/farmacologia , Antagonistas Adrenérgicos alfa/síntese química , Antagonistas Adrenérgicos alfa/química , Antagonistas Adrenérgicos alfa/metabolismo , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Aorta Torácica/efeitos dos fármacos , Células CHO , Clonagem Molecular , Cricetinae , Dioxanos/química , Dioxanos/metabolismo , Dioxanos/farmacologia , Células HeLa , Humanos , Técnicas In Vitro , Masculino , Contração Muscular/efeitos dos fármacos , Músculo Liso/efeitos dos fármacos , Ensaio Radioligante , Ratos , Ratos Sprague-Dawley , Receptores Adrenérgicos alfa 1/efeitos dos fármacos , Receptores de Serotonina/efeitos dos fármacos , Receptores 5-HT1 de Serotonina , Antagonistas da Serotonina/síntese química , Antagonistas da Serotonina/química , Antagonistas da Serotonina/metabolismo , Antagonistas da Serotonina/farmacologia , Agonistas do Receptor de Serotonina/síntese química , Agonistas do Receptor de Serotonina/química , Agonistas do Receptor de Serotonina/metabolismo , Agonistas do Receptor de Serotonina/farmacologia , Baço/efeitos dos fármacos , Estereoisomerismo , Relação Estrutura-Atividade , Ducto Deferente/efeitos dos fármacosRESUMO
delta-Opioid receptors belong to the superfamily of G protein-coupled receptors, characterized by seven putative transmembrane domains, and have been shown to interact with a host of effector systems. It has been suggested that the charge on the conserved aspartic acid residue at position 128 in transmembrane domain 3 of the delta-opioid receptor contributes to both the conformation of the receptor binding pocket and the molecular rearrangements which accompany the establishment of high-affinity states of the receptor. In light of this, we used site-directed mutagenesis to determine whether this residue participates in the transmission of signals to adenylyl cyclase, the effector with which opioid receptors have been classically associated. Substitution of this aspartic acid (D128) for the neutral amino acid alanine, or the protonated amino acids lysine and histidine, constitutively couples the receptor to adenylyl cyclase, as evidenced by a curtailed response to forskolin stimulation in transfected cells. In addition, this constitutive activity can be blocked by pretreatment of the transfected cells with pertussis toxin. Interestingly, naloxone blocks this effect in cells expressing the D128A mutant, but acts as an agonist at the D128K mutant. Our findings support the hypothesis that the interaction between agonist and receptor promotes conformational changes that may be mimicked, at least in part, by mutation of the aspartate residue at position 128. Furthermore, these changes appear to be involved not only in receptor activation, but also in the functional discrimination between agonists and antagonists.
Assuntos
Adenilil Ciclases/metabolismo , Mutação Puntual , Receptores Opioides delta/genética , Sistemas do Segundo Mensageiro/fisiologia , Toxina Adenilato Ciclase , Inibidores de Adenilil Ciclases , Substituição de Aminoácidos , Animais , Ácido Aspártico/química , Ligação Competitiva , Células COS , Chlorocebus aethiops , Códon/genética , Colforsina/farmacologia , AMP Cíclico/biossíntese , DNA Complementar/genética , Diprenorfina/metabolismo , D-Penicilina (2,5)-Encefalina , Encefalinas/farmacologia , Proteínas de Ligação ao GTP/metabolismo , Ligantes , Camundongos , Mutagênese Sítio-Dirigida , Naloxona/metabolismo , Toxina Pertussis , Ligação Proteica/efeitos dos fármacos , Receptores Opioides delta/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Sistemas do Segundo Mensageiro/efeitos dos fármacos , Transfecção , Fatores de Virulência de Bordetella/farmacologiaRESUMO
HLA-DP genotyping of 500 donor recipient pairs in a retrospective analysis sponsored by the National Marrow Donor Program (NMDP) identified four new DP alleles, two DPB1 and two DPA1. DNA sequencing confirmed that DPB1*8001 and *8101, each found in a single individual, are novel combinations of previously described sequence motifs in the six variable regions of DPB1. DPA1*02014, found in two individuals, is identical to DPA1*02011 except for a novel silent substitution, a G to A transition at the third position of codon 14. DPA1*01032, found in one individual, is identical to DPB1*01031 except for a silent G to A transition at the third position of codon 20. The identification of these novel alleles brings the total number of reported DPB1 alleles to 85 and DPA1 alleles to 15.
Assuntos
Alelos , Doadores de Sangue , Antígenos HLA-DP/genética , Sequência de Aminoácidos , Sequência de Bases , Medula Óssea , DNA Complementar , Genótipo , Antígenos HLA-DP/classificação , Cadeias alfa de HLA-DP , Cadeias beta de HLA-DP , Humanos , Dados de Sequência Molecular , Homologia de Sequência de Aminoácidos , Homologia de Sequência do Ácido NucleicoRESUMO
Aromatase is a cytochrome P450 isozyme, whose inhibition is known to be therapeutically relevant in the treatment of the breast cancer. A comparative molecular field analysis (CoMFA) has been carried out on a series of non-steroidal aromatase inhibitors belonging to two different structural classes. One subset of compounds consists of fadrozole analogues and was studied in a previous work, from which a 'local' 3-D quantitative structure-activity relationship (QSAR) model for the inhibition of aromatase was obtained. In the present paper, that model is extended to include a second subset of compounds bearing a tetralone nucleus and acting at the same enzyme site with the same mechanism as the azoles. The critical alignment step has been solved by using two different steroidal inhibitors of aromatase as rigid templates, on which the non-steroidal compounds have been superimposed. The final 3-D QSAR models are discussed in terms of predictivity and some implications regarding the steric and electronic requirements of steroidal and non-steroidal inhibitors are pointed out.
Assuntos
Inibidores da Aromatase , Azóis/química , Fadrozol/química , Tetra-Hidronaftalenos/química , Azóis/farmacologia , Fadrozol/análogos & derivados , Fadrozol/farmacologia , Modelos Químicos , Estrutura Molecular , Relação Estrutura-Atividade , Tetra-Hidronaftalenos/farmacologiaRESUMO
Cell-mediated immune responses to hepatitis B (HBV) and hepatitis C virus (HCV) antigens are vigorous and multispecific in acute, self-limited infections. Moreover, the prevalent cytokine pattern of circulating virus-specific T cells from patients who recover spontaneously from acute hepatitis is Th1-like. Longitudinal analysis of the T cell response to HCV antigens from the early stages of HCV infection in patients who recover from hepatitis and those who do not indicates that weaker responses and a prevalent Th2 pattern of cytokine production is associated with viral persistence and chronic evolution of disease. Although similar sequential studies are missing in hepatitis B, the observation that HBV-specific T cell responses are very weak or totally undetectable in the peripheral blood of patients with long-lasting chronic hepatitis B suggests that strength and quality of virus-specific T cell responses at the early stages of infection may influence the final outcome of both hepatitis B and C. While T cell hyporesponsiveness seems to be an important determinant for HBV persistence once chronic hepatitis has developed, this mechanism appears to be less critical in chronic HCV infection, because the vigor and quality of HCV-specific T cell responses seem to improve as a function of the duration of infection. This is shown by the finding that HCV-specific CD4- and CD8-mediated responses are easily detectable in the peripheral blood of patients with long-lasting chronic hepatitis C and that production of Th1 cytokines predominates within their livers. HCV therefore seems to be able to persist even in the face of an active T cell response and to acquire the capacity to survive within a host environment apparently unfavorable to its persistence. The high variability of HCV may explain its efficiency in escaping immune surveillance.