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1.
J Crim Justice ; 86: 102050, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36911596

RESUMO

On March 10, 2020, the Governor of the State of Michigan, USA, declared a state of emergency in response to COVID-19. Within days, schools were closed; in-person dining was restricted; and lockdowns and precautionary stay-at-home orders were issued. These restrictions dramatically impacted the mobility of offenders and victims through space and time. As routine activities were forced to change and crime generators were closed, did hot spots and risky locations for victimization change as well? The purpose of this research is to analyze potential shifts in high-risk areas for sexual assaults before, during, and after COVID-19 restrictions. Using data from the City of Detroit, Michigan, USA, optimized hot spot analysis and Risk Terrain Modeling (RTM) were used to identify critical spatial factors for the occurrence of sexual assaults before, during, and after COVID-19 restrictions. The results suggested that hot spot areas for sexual assaults were more concentrated during the COVID timeframe, compared to the Pre-COVID timeframe. While blight complaints, public transit stops, points of sale for liquor, and the locations of drug arrests were consistent risk factors for sexual assaults before and after COVID restrictions, other factors, such as casinos and demolitions, were only influential in the COVID period.

2.
Regul Toxicol Pharmacol ; 117: 104746, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32911461

RESUMO

Pharmaceutic products designed to perturb the function of epigenetic modulators have been approved by regulatory authorities for treatment of advanced cancer. While the predominant effort in epigenetic drug development continues to be in oncology, non-oncology indications are also garnering interest. A survey of pharmaceutical companies was conducted to assess the interest and concerns for developing small molecule direct epigenetic effectors (EEs) as medicines. Survey themes addressed (1) general levels of interest and activity with EEs as therapeutic agents, (2) potential safety concerns, and (3) possible future efforts to develop targeted strategies for nonclinical safety assessment of EEs. Thirteen companies contributed data to the survey. Overall, the survey data indicate the consensus opinion that existing ICH guidelines are effective and appropriate for nonclinical safety assessment activities with EEs. Attention in the framework of study design should, on a case by case basis, be considered for delayed or latent toxicities, carcinogenicity, reproductive toxicity, and the theoretical potential for transgenerational effects. While current guidelines have been appropriate for the nonclinical safety assessments of epigenetic targets, broader experience with a wide range of epigenetic targets will provide information to assess the potential need for new or revised risk assessment strategies for EE drugs.


Assuntos
Indústria Farmacêutica/normas , Controle de Medicamentos e Entorpecentes , Epigênese Genética/efeitos dos fármacos , Preparações Farmacêuticas/normas , Inquéritos e Questionários , Animais , Avaliação Pré-Clínica de Medicamentos/normas , Avaliação Pré-Clínica de Medicamentos/tendências , Indústria Farmacêutica/tendências , Controle de Medicamentos e Entorpecentes/tendências , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/epidemiologia , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos/prevenção & controle , Epigênese Genética/genética , Humanos , Preparações Farmacêuticas/administração & dosagem , Medição de Risco/normas , Medição de Risco/tendências
3.
Toxicol Appl Pharmacol ; 334: 100-109, 2017 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-28893587

RESUMO

The contribution of animal testing in drug development has been widely debated and challenged. An industry-wide nonclinical to clinical translational database was created to determine how safety assessments in animal models translate to First-In-Human clinical risk. The blinded database was composed of 182 molecules and contained animal toxicology data coupled with clinical observations from phase I human studies. Animal and clinical data were categorized by organ system and correlations determined. The 2×2 contingency table (true positive, false positive, true negative, false negative) was used for statistical analysis. Sensitivity was 48% with a 43% positive predictive value (PPV). The nonhuman primate had the strongest performance in predicting adverse effects, especially for gastrointestinal and nervous system categories. When the same target organ was identified in both the rodent and nonrodent, the PPV increased. Specificity was 84% with an 86% negative predictive value (NPV). The beagle dog had the strongest performance in predicting an absence of clinical adverse effects. If no target organ toxicity was observed in either test species, the NPV increased. While nonclinical studies can demonstrate great value in the PPV for certain species and organ categories, the NPV was the stronger predictive performance measure across test species and target organs indicating that an absence of toxicity in animal studies strongly predicts a similar outcome in the clinic. These results support the current regulatory paradigm of animal testing in supporting safe entry to clinical trials and provide context for emerging alternate models.


Assuntos
Bases de Dados Factuais , Pesquisa Translacional Biomédica , Animais , Avaliação Pré-Clínica de Medicamentos , Indústria Farmacêutica , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Humanos , Modelos Animais , Medição de Risco
4.
Birth Defects Res B Dev Reprod Toxicol ; 104(6): 244-52, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26626128

RESUMO

Dabrafenib (DAB), an inhibitor of BRAF kinase activity, is approved for metastatic melanoma with a BRAF V600E mutation. In support of pediatric cancer development, a nonclinical juvenile rat toxicity study was conducted in which females had early vaginal opening (VO). It was hypothesized that the early VO was not indicative of sexual maturation, but a result of a local effect on the vagina. An investigative study was conducted that mimicked the definitive study design, with rats given DAB or vehicle orally from Postnatal Day (PND) 7 to 35 and with necropsy subsets just before VO, at the first and second estrus, along with age-matched controls. Histopathology was performed on reproductive tissues, including immunohistochemistry for BRAF expression. VO occurred earlier in DAB females than in controls (PND 27.2 vs. 31.5); however, the timing of the first estrus was unaffected (PND 34.0 vs. 33.0). DAB-treated females evaluated just before VO (PND 22.0) had mostly immature reproductive tracts with no evidence of ovulation, similar to age-matched controls; however, DAB-treated females had keratinized and histologically open vaginas. Also, there was raised skin around the urogenital area, which correlated with hyperplasia/keratosis of the vulvar skin and keratinization of the distal vagina. BRAF expression (evaluated in controls) was localized to these tissues. Thus, early VO in rats given DAB likely represents a local effect accelerating vaginal keratinization to become open and not accelerated sexual maturation.


Assuntos
Imidazóis/farmacologia , Oximas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Maturidade Sexual/efeitos dos fármacos , Vagina/fisiologia , Animais , Estro/efeitos dos fármacos , Feminino , Imuno-Histoquímica , Proteínas Proto-Oncogênicas B-raf/metabolismo , Ratos Sprague-Dawley , Vagina/citologia , Vagina/efeitos dos fármacos
5.
Cancer Chemother Pharmacol ; 92(6): 455-464, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37505272

RESUMO

The first-in-patient (FIP) starting dose for oncology agents should be reasonably safe and provide potential therapeutic benefit to the patient. For late-stage oncology patients, this dose is often based on the ICH S9 guidance, which was developed primarily based on experience with cytotoxic chemotherapeutic agents using the rodent STD10 or non-rodent HNSTD and an appropriate safety factor. With the increase in molecularly targeted chemotherapeutics, it is prudent to re-evaluate how the FIP dose is derived to ensure that the appropriate balance between risk and therapeutic benefit to the patient is achieved. Blinded data on 92 small molecule oncology compounds from 12 pharmaceutical companies who are members of the IQ DruSafe consortium were gathered to investigate if a NOAEL-based starting dose without a safety factor would have been tolerated in the FIP trial and if so, estimating how many dose escalation cohorts could have been reduced. Our analysis suggests that the NOAEL-based alternative starting dose would have been tolerated in most cases evaluated, with an anticipated mean reduction of 2.3 cohorts. Of the 12 cases where the alternative approach resulted in a starting dose that would have exceeded the MTD/RP2D, none of the nonclinical toxicities in these cases were considered irreversible and would be monitorable in all but one instance. Most non-tolerated cases were within two-threefold of the MTD/RP2D, with the clinical AEs considered manageable and mitigated by dose de-escalation. No one method of FIP dose calculation will likely be appropriate for all oncology small molecules and starting dose selection should be performed using a case-by-case approach. However, the NOAEL-based method that does not utilize a safety factor should be considered when appropriate to minimize the number of patients exposed to sub-therapeutic doses of an investigational oncology agent and accelerating development to RP2D.


Assuntos
Antineoplásicos , Neoplasias , Humanos , Nível de Efeito Adverso não Observado , Antineoplásicos/efeitos adversos , Dose Máxima Tolerável , Neoplasias/tratamento farmacológico , Oncologia , Relação Dose-Resposta a Droga
6.
Cancer Cell ; 36(2): 194-209.e9, 2019 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-31408619

RESUMO

Cancer-associated mutations in genes encoding RNA splicing factors (SFs) commonly occur in leukemias, as well as in a variety of solid tumors, and confer dependence on wild-type splicing. These observations have led to clinical efforts to directly inhibit the spliceosome in patients with refractory leukemias. Here, we identify that inhibiting symmetric or asymmetric dimethylation of arginine, mediated by PRMT5 and type I protein arginine methyltransferases (PRMTs), respectively, reduces splicing fidelity and results in preferential killing of SF-mutant leukemias over wild-type counterparts. These data identify genetic subsets of cancer most likely to respond to PRMT inhibition, synergistic effects of combined PRMT5 and type I PRMT inhibition, and a mechanistic basis for the therapeutic efficacy of PRMT inhibition in cancer.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Etilenodiaminas/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Pirróis/farmacologia , Splicing de RNA/efeitos dos fármacos , RNA Neoplásico/metabolismo , Animais , Antineoplásicos/farmacocinética , Catálise , Inibidores Enzimáticos/farmacocinética , Etilenodiaminas/farmacocinética , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Humanos , Células K562 , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteína-Arginina N-Metiltransferases/genética , Proteína-Arginina N-Metiltransferases/metabolismo , Pirróis/farmacocinética , RNA Neoplásico/genética , Proteínas Repressoras/antagonistas & inibidores , Proteínas Repressoras/metabolismo , Células THP-1 , Células Tumorais Cultivadas , Células U937 , Ensaios Antitumorais Modelo de Xenoenxerto
7.
Cancer Cell ; 36(1): 100-114.e25, 2019 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-31257072

RESUMO

Type I protein arginine methyltransferases (PRMTs) catalyze asymmetric dimethylation of arginines on proteins. Type I PRMTs and their substrates have been implicated in human cancers, suggesting inhibition of type I PRMTs may offer a therapeutic approach for oncology. The current report describes GSK3368715 (EPZ019997), a potent, reversible type I PRMT inhibitor with anti-tumor effects in human cancer models. Inhibition of PRMT5, the predominant type II PRMT, produces synergistic cancer cell growth inhibition when combined with GSK3368715. Interestingly, deletion of the methylthioadenosine phosphorylase gene (MTAP) results in accumulation of the metabolite 2-methylthioadenosine, an endogenous inhibitor of PRMT5, and correlates with sensitivity to GSK3368715 in cell lines. These data provide rationale to explore MTAP status as a biomarker strategy for patient selection.


Assuntos
Antineoplásicos/farmacologia , Inibidores Enzimáticos/farmacologia , Proteína-Arginina N-Metiltransferases/antagonistas & inibidores , Purina-Núcleosídeo Fosforilase/deficiência , Processamento Alternativo , Antineoplásicos/química , Biomarcadores , Linhagem Celular Tumoral , Sinergismo Farmacológico , Inibidores Enzimáticos/química , Humanos , Metilação , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Ligação Proteica , Proteína-Arginina N-Metiltransferases/química , Especificidade por Substrato
8.
Violence Vict ; 23(5): 637-51, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18958990

RESUMO

The current research explores two important issues related to the study of bystander intervention during nonfatal violent victimization. First, using data from the National Crime Victimization Survey (NCVS), conjunctive analysis of case configurations is conducted to identify the most dominant situational contexts in which a bystander is present during violent crime. Second, the prevalence of responses in which a bystander helps or hurts during these events is determined. Results and the analytical approach used in this investigation are discussed in terms of their implications for future research on the normative and deviant reactions to crime by third parties and its victims.


Assuntos
Vítimas de Crime/estatística & dados numéricos , Primeiros Socorros/estatística & dados numéricos , Comportamento de Ajuda , Percepção Social , Violência/estatística & dados numéricos , Agressão , Feminino , Humanos , Relações Interpessoais , Masculino , Prevalência , Meio Social , Estados Unidos/epidemiologia
10.
Cancer Cell ; 28(1): 57-69, 2015 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-26175415

RESUMO

Epigenetic dysregulation has emerged as an important mechanism in cancer. Alterations in epigenetic machinery have become a major focus for targeted therapies. The current report describes the discovery and biological activity of a cyclopropylamine containing inhibitor of Lysine Demethylase 1 (LSD1), GSK2879552. This small molecule is a potent, selective, orally bioavailable, mechanism-based irreversible inactivator of LSD1. A proliferation screen of cell lines representing a number of tumor types indicated that small cell lung carcinoma (SCLC) is sensitive to LSD1 inhibition. The subset of SCLC lines and primary samples that undergo growth inhibition in response to GSK2879552 exhibit DNA hypomethylation of a signature set of probes, suggesting this may be used as a predictive biomarker of activity.


Assuntos
Antineoplásicos/administração & dosagem , Benzoatos/administração & dosagem , Ciclopropanos/administração & dosagem , Metilação de DNA/efeitos dos fármacos , Inibidores Enzimáticos/administração & dosagem , Histona Desmetilases/antagonistas & inibidores , Neoplasias Pulmonares/tratamento farmacológico , Carcinoma de Pequenas Células do Pulmão/tratamento farmacológico , Administração Oral , Animais , Antineoplásicos/farmacologia , Benzoatos/farmacologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Ciclopropanos/farmacologia , Inibidores Enzimáticos/farmacologia , Epigênese Genética/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Histona Desmetilases/genética , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Dados de Sequência Molecular , Carcinoma de Pequenas Células do Pulmão/genética , Carcinoma de Pequenas Células do Pulmão/patologia , Ensaios Antitumorais Modelo de Xenoenxerto
11.
Stroke ; 33(2): 578-85, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11823673

RESUMO

BACKGROUND AND PURPOSE: Although used clinically to prevent stroke, there are few examples of anticoagulant investigations in the treatment of acute thromboembolic stroke in animal models. The treatment of thromboembolic stroke in experimental models has been investigated almost exclusively around the use of tissue plasminogen activator (tPA). In this study, using a rat thromboembolic stroke model, we investigated the use of an inhibitory anti-factor IX(a) monoclonal antibody (SB 249417) for the treatment of thromboembolic stroke and compared its efficacy to that of tPA. METHODS: Stroke was initiated by delivering 6 clots into the internal carotid artery. After 2, 4, or 6 hours, rats received either intravenous vehicle, 10.0 mg/kg tPA, or 1.0, 2.0, or 3.0 mg/kg SB 249417. At 24 hours after stroke, infarct volumes and neurological deficits were assessed. RESULTS: Treatment with tPA 2, 4, or 6 hours after stroke reduced infarct volumes by 35% (P=NS), 45%, and 39%, respectively. tPA treatment did not improve neurological deficits at any time point. Treatment with SB 249417 (3.0 mg/kg) 2, 4, or 6 hours after stroke reduced infarct volumes by 44%, 50%, and 13% (P=NS), respectively. Neurological deficits were reduced by 49%, 42%, and 13% (P=NS), respectively. Neither mortality nor hemorrhage was affected by either treatment. CONCLUSIONS: The data indicate that the inhibition of factor IX(a) within 4 hours of thromboembolic stroke produced a more favorable outcome than tPA. When treatment was initiated 6 hours after stroke, the benefits of factor IX(a) inhibition were lost, whereas tPA continued to suppress lesion development, albeit without a corresponding improvement in functional deficits. This study suggests that cerebral ischemia and the resultant perfusion deficit are exacerbated by the activation of blood coagulation and that anticoagulants like SB 249417 may find utility in the treatment of ischemic stroke.


Assuntos
Anticorpos Monoclonais/uso terapêutico , Fator IXa/antagonistas & inibidores , Fibrinolíticos/uso terapêutico , Acidente Vascular Cerebral/terapia , Tromboembolia/terapia , Doença Aguda , Animais , Comportamento Animal/efeitos dos fármacos , Modelos Animais de Doenças , Progressão da Doença , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Exame Neurológico , Ativadores de Plasminogênio/uso terapêutico , Prosencéfalo/irrigação sanguínea , Prosencéfalo/efeitos dos fármacos , Prosencéfalo/patologia , Ratos , Acidente Vascular Cerebral/etiologia , Acidente Vascular Cerebral/fisiopatologia , Taxa de Sobrevida , Tromboembolia/complicações , Tromboembolia/patologia , Fatores de Tempo , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento
12.
Toxicol Sci ; 69(1): 131-8, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12215667

RESUMO

Troglitazone (TRO), a member of the thiazolidinedione class of drugs, has been associated with hepatotoxicity in patients. The following in vitro study was conducted to investigate the effects of TRO on mitochondrial function and viability in a human hepatoma cell line, HepG2. TRO induced a concentration- and time-dependent increase in cell death, as measured by lactate dehydrogenase release. Exposure to 50 or 100 micro M TRO produced total loss of cell viability within 5 h. Preincubation of HepG2 cells with P450 inhibitors did not significantly protect against TRO-induced cell death suggesting that P450 metabolism was not required to induce cell death. Preincubation with the mitochondrial permeability transition inhibitor, cyclosporin A, provided complete protection against TRO-induced cell death. Our results also indicated that TRO produced concentration-dependent decreases in cellular ATP levels and mitochondrial membrane potential (MMP). Ultrastructural analysis demonstrated that TRO induced mitochondrial changes at concentrations of > or =10 micro M after 2 h. Decreased MMP and altered mitochondrial morphology occurred at time points that preceded cell death and at sublethal concentrations of TRO. These observations in HepG2 cells suggest that TRO disrupts mitochondrial function, leading to mitochondrial permeability transition and cell death.


Assuntos
Cromanos/farmacologia , Hipoglicemiantes/farmacologia , Mitocôndrias Hepáticas/efeitos dos fármacos , Tiazóis/farmacologia , Tiazolidinedionas , Trifosfato de Adenosina/metabolismo , Morte Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Inibidores das Enzimas do Citocromo P-450 , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Humanos , Microscopia Confocal , Microscopia Eletrônica , Mitocôndrias Hepáticas/ultraestrutura , Permeabilidade , Fatores de Tempo , Troglitazona , Células Tumorais Cultivadas
13.
J Med Chem ; 52(5): 1408-15, 2009 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-19222165

RESUMO

N-tert-Butyl isoquine (4) (GSK369796) is a 4-aminoquinoline drug candidate selected and developed as part of a public-private partnership between academics at Liverpool, MMV, and GSK pharmaceuticals. This molecule was rationally designed based on chemical, toxicological, pharmacokinetic, and pharmacodynamic considerations and was selected based on excellent activity against Plasmodium falciparum in vitro and rodent malaria parasites in vivo. The optimized chemistry delivered this novel synthetic quinoline in a two-step procedure from cheap and readily available starting materials. The molecule has a full industry standard preclinical development program allowing first into humans to proceed. Employing chloroquine (1) and amodiaquine (2) as comparator molecules in the preclinical plan, the first preclinical dossier of pharmacokinetic, toxicity, and safety pharmacology has also been established for the 4-aminoquinoline antimalarial class. These studies have revealed preclinical liabilities that have never translated into the human experience. This has resulted in the availability of critical information to other drug development teams interested in developing antimalarials within this class.


Assuntos
Aminoquinolinas/farmacologia , Antimaláricos/farmacologia , Benzilaminas/farmacologia , Aminoquinolinas/síntese química , Aminoquinolinas/química , Aminoquinolinas/farmacocinética , Aminoquinolinas/toxicidade , Amodiaquina/análogos & derivados , Animais , Antimaláricos/síntese química , Antimaláricos/farmacocinética , Antimaláricos/toxicidade , Benzilaminas/síntese química , Benzilaminas/química , Benzilaminas/toxicidade , Inibidores das Enzimas do Citocromo P-450 , Cães , Avaliação Pré-Clínica de Medicamentos , Resistência a Medicamentos , Feminino , Haplorrinos , Heme/química , Humanos , Malária/tratamento farmacológico , Camundongos , Modelos Moleculares , Plasmodium berghei/efeitos dos fármacos , Plasmodium falciparum/efeitos dos fármacos , Plasmodium yoelii , Ratos , Relação Estrutura-Atividade
14.
J Virol ; 80(19): 9667-75, 2006 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16973571

RESUMO

The NSs protein of Bunyamwera virus (Bunyaviridae) is an antiapoptotic interferon antagonist involved in silencing host protein expression by interfering with mRNA synthesis. Here, we show that the ability to inhibit both host transcription and the interferon response is linked to interaction of NSs with the MED8 component of Mediator, a protein complex necessary for mRNA production. The interacting domain on NSs was mapped to the C-terminal region, which contains amino acids conserved among orthobunyavirus NSs proteins. A recombinant virus in which the interacting domain in NSs was deleted had strongly reduced ability to inhibit host protein expression and was unable to inhibit the interferon response. This study provides further information on the mechanisms by which bunyavirus nonstructural proteins are involved in pathogenesis.


Assuntos
Interferons/antagonistas & inibidores , Orthobunyavirus/metabolismo , Fatores de Transcrição/metabolismo , Proteínas Virais/metabolismo , Sequência de Aminoácidos , Animais , Sequência de Bases , Linhagem Celular , Cricetinae , RNA Polimerases Dirigidas por DNA/metabolismo , Humanos , Imunidade Inata/imunologia , Interferons/genética , Interferons/imunologia , Complexo Mediador , Dados de Sequência Molecular , Orthobunyavirus/química , Orthobunyavirus/genética , Orthobunyavirus/imunologia , Ligação Proteica , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/genética , Técnicas do Sistema de Duplo-Híbrido , Proteínas Virais/química , Proteínas Virais/genética
15.
J Virol ; 79(9): 5326-36, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15827147

RESUMO

Respiratory syncytial virus (RSV) is an important human pathogen that can cause severe and life-threatening respiratory infections in infants, the elderly, and immunocompromised adults. RSV infection of HEp-2 cells induces the activation of RhoA, a small GTPase. We therefore asked whether RhoA signaling is important for RSV replication or syncytium formation. The treatment of HEp-2 cells with Clostridium botulinum C3, an enzyme that ADP-ribosylates and specifically inactivates RhoA, inhibited RSV-induced syncytium formation and cell-to-cell fusion, although similar levels of PFU were released into the medium and viral protein expression levels were equivalent. Treatment with another inhibitor of RhoA signaling, the Rho kinase inhibitor Y-27632, yielded similar results. Scanning electron microscopy of C3-treated infected cells showed reduced numbers of single blunted filaments, in contrast to the large clumps of long filaments in untreated infected cells. These data suggest that RhoA signaling is associated with filamentous virus morphology, cell-to-cell fusion, and syncytium formation but is dispensable for the efficient infection and production of infectious virus in vitro. Next, we developed a semiquantitative method to measure spherical and filamentous virus particles by using sucrose gradient velocity sedimentation. Fluorescence and transmission electron microscopy confirmed the separation of spherical and filamentous forms of infectious virus into two identifiable peaks. The C3 treatment of RSV-infected cells resulted in a shift to relatively more spherical virions than those from untreated cells. These data suggest that viral filamentous protuberances characteristic of RSV infection are associated with RhoA signaling, are important for filamentous virion morphology, and may play a role in initiating cell-to-cell fusion.


Assuntos
Vírus Sinciciais Respiratórios/fisiologia , Transdução de Sinais , Proteína rhoA de Ligação ao GTP/metabolismo , ADP Ribose Transferases/farmacologia , Amidas/farmacologia , Toxinas Botulínicas/farmacologia , Linhagem Celular , Células Gigantes/ultraestrutura , Humanos , Piridinas/farmacologia , Vírus Sinciciais Respiratórios/efeitos dos fármacos , Vírus Sinciciais Respiratórios/ultraestrutura , Replicação Viral , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores
16.
Toxicol Pathol ; 31(5): 554-61, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-14692624

RESUMO

Recombinant human interleukin-18 (rHuIL-18) is currently in clinical trials for treatment of cancer. This report presents results of preclinical toxicity studies with rHuIL-18 in cynomolgus monkeys and recombinant murine IL-18 (rMuIL-18) in mice. The rHuIL-18 was administered intravenously in 1 or 2 different 5-day cycles at doses 0.3 to 75 mg/kg/day in monkeys. Decreases in red cell mass, neutrophil, and platelet counts, increases in monocyte and large unstained cell counts, and lymphoid hyperplasia in spleen and lymph nodes were mild, reversible, and likely related to the pharmacologic activity of IL-18. The only toxic effect was protein cast nephropathy, secondary to coprecipitation of administered IL-18 and Tamm-Horsfall protein in the distal nephron, that only occurred at 75 mg/kg/day. Other adverse effects of rHuIL-18 were related to strong immunogenicity in monkeys and were manifest only during a second dosing cycle. The rMuIL-18, at similar dosing levels and cycles in mice, resulted in reduced red cell mass, increased white blood cell counts, spleen and lymph node hyperplasia, and mild, reversible changes in intestine, liver, and lungs. Protein cast nephropathy occurred in mice at doses > or = 30 mg/kg/day. In conclusion, preclinical safety studies showed that rIL-18 was well tolerated at pharmacologically active doses in both monkeys and mice.


Assuntos
Interleucina-18/toxicidade , Animais , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Humanos , Hiperplasia , Imuno-Histoquímica , Injeções Intravenosas , Interleucina-18/administração & dosagem , Interleucina-18/farmacocinética , Rim/efeitos dos fármacos , Rim/patologia , Rim/ultraestrutura , Linfonodos/efeitos dos fármacos , Linfonodos/patologia , Macaca fascicularis , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Mucoproteínas/efeitos dos fármacos , Nefrose Lipoide/etiologia , Proteínas Recombinantes/administração & dosagem , Proteínas Recombinantes/toxicidade , Baço/efeitos dos fármacos , Baço/patologia , Fatores de Tempo , Uromodulina
17.
J Virol ; 78(11): 5679-85, 2004 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-15140965

RESUMO

Artificial minigenomes are powerful tools for studying the replication and transcription of negative-strand RNA viruses. Bunyamwera virus (BUN; genus Orthobunyavirus, family Bunyaviridae) is an arbovirus that shows fundamental biological differences when replicating in mammalian versus mosquito cells. To study BUN RNA synthesis in mosquito cells, we developed a bacteriophage T7 RNA polymerase-based minireplicon system similar to that described previously for mammalian cells. An Aedes albopictus C6/36-derived mosquito cell line stably expressing T7 RNA polymerase was established. Viral proteins and artificial minigenomes (containing Renilla luciferase as a reporter) were transcribed and expressed in these cells from transfected T7 promoter-containing plasmids. Transcription of the minigenome required two viral proteins, the nucleocapsid protein N and the RNA-dependent RNA polymerase L, a situation similar to that in mammalian cells. However, unlike the situation in mammalian cells, the viral polymerase was not inhibited by the viral nonstructural protein NSs. We also report that promoter strength is different for vertebrate versus invertebrate cells. The development of this system opens the way for a detailed comparison of bunyavirus replication in cells of disparate phylogeny.


Assuntos
Aedes/virologia , Vírus Bunyamwera/fisiologia , Replicon , Replicação Viral , Animais , RNA Polimerases Dirigidas por DNA/metabolismo , Regiões Promotoras Genéticas , Biossíntese de Proteínas , Transcrição Gênica , Proteínas Virais
18.
Cytometry A ; 52(1): 28-35, 2003 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-12596249

RESUMO

BACKGROUND: Troglitazone (TRO), a thiazolidinedione (TZD) peroxisome proliferator-activated receptor gamma agonist, was recently withdrawn from the market because of rare but serious hepatotoxicity. Previous studies investigating the cytotoxicity of TRO in cultured rat hepatocytes have conjectured about the role of oxidative stress in TRO-induced hepatotoxicity. Therefore, we investigated whether TRO induces oxidative stress and, if so, the portion of the TRO molecule responsible for the induction of oxidative stress. METHODS: Novikoff rat hepatoma (N1S1) cells were incubated with TRO, troglitazone quinone (TQ), thiazolidinedione-phenoxyacetic acid (TD-PAA) or rosiglitazone (RSG). Membrane peroxidation, intracellular glutathione (GSH) content, and cellular viability were monitored simultaneously by multiparameter flow cytometry. RESULTS: TRO and TQ increased membrane peroxidation, decreased intracellular GSH, and decreased cell viability in a concentration-dependent manner. In contrast, TD-PAA and RSG neither increased membrane peroxidation nor induced loss of cell viability. In addition, TRO caused a concentration-dependent increase in intracellular superoxide generation accompanied by a collapse in mitochondrial membrane potential. CONCLUSION: Multiparameter flow cytometric evaluation of N1S1 cells indicated that the chromane ring of TRO, rather than the TZD moiety, may be responsible for oxidative stress and suggested that a direct effect on mitochondrial physiology may play a role in TRO-mediated hepatotoxicity.


Assuntos
Carcinoma Hepatocelular/metabolismo , Cromanos/farmacologia , Estresse Oxidativo , Tiazolidinedionas/farmacologia , Animais , Linhagem Celular , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Corantes/farmacologia , Relação Dose-Resposta a Droga , Fibrinolíticos/farmacologia , Citometria de Fluxo , Fluoresceínas/farmacologia , Corantes Fluorescentes/farmacologia , Glutationa/metabolismo , Potenciais da Membrana , Mitocôndrias/metabolismo , Modelos Químicos , Oxigênio/metabolismo , Fenantridinas/química , Propídio/farmacologia , Ratos , Rosiglitazona , Superóxidos/metabolismo , Troglitazona
19.
J Immunol ; 172(8): 5078-85, 2004 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-15067091

RESUMO

Lupus-prone New Zealand Black and New Zealand White mice produce high serum levels of the endogenous retroviral envelope protein gp70 and develop an Ab response to this autoantigen as part of their autoimmune disease. Linkage analysis of two crosses involving New Zealand and BALB/c mice mapped these traits to a group of overlapping loci, including a novel locus on proximal chromosome 12. This locus was linked with serum gp70 and the autoimmune response against it. The linkage of serum gp70 levels to a previously described locus on distal chromosome 4 was also confirmed. Sequence analysis of a candidate gene on distal chromosome 4, Fv1, provided support that this gene may be associated with the control of serum gp70 levels in both New Zealand Black and New Zealand White mice. Linkage data and statistical analysis confirmed a close correlation between gp70 Ag and anti-gp70 Ab levels, and together gave support to the concept that a threshold level of gp70 is required for the production of anti-gp70 Abs. Serum levels of anti-gp70 Abs were closely correlated with the presence of renal disease, more so than anti-dsDNA Abs. Understanding the genetic basis of this complex autoantigen-autoantibody system will provide insight into the pathogenesis of lupus in mice, which may have implications for human disease.


Assuntos
Anticorpos Antivirais/biossíntese , Regulação da Expressão Gênica/imunologia , Marcadores Genéticos/imunologia , Glicoproteínas/imunologia , Retroviridae/imunologia , Proteínas do Envelope Viral/imunologia , Animais , Anticorpos Antivirais/sangue , Mapeamento Cromossômico , Cruzamentos Genéticos , Feminino , Ligação Genética , Predisposição Genética para Doença , Glomerulonefrite/genética , Glomerulonefrite/imunologia , Glicoproteínas/sangue , Camundongos , Camundongos Congênicos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos NZB , Proteínas/genética , Especificidade da Espécie , Proteínas do Envelope Viral/sangue
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