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1.
Toxicol Rep ; 12: 477-484, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38708314

RESUMO

Yerba Mate (Ilex paraguariensis) is historically used as a beverage and its extracts are considered traditional medicine in South America. Extract use has been expanding to North American and European markets and the currently available genetic toxicology literature indicate discrepancies in genotoxicity findings for yerba mate. As botanical extract use expands, assumption in safety should be made with caution assuring a good understanding of the test material characterization. Authoritative agencies suggest a two-step paradigm to investigate genotoxicity, and this was implemented to evaluate the safety of yerba mate hydroxycinnamic acid extract. Four OECD compliant assays were employed: bacterial reverse mutation, in vitro micronucleus and a parallel in vivo micronucleus, and comet assay. No evidence of mutagenicity was observed in the in vitro Ames assay, but the results of an in vitro micronucleus study were inconclusive. However, oral gavage treatment of rats for the in vivo micronucleus and comet assays demonstrated negative findings. The results from this battery of tests, supports that this yerba mate hydroxycinnamic acid extract is not anticipated to pose genotoxicity concerns. A high-level comparison of results to other available genotoxicity literature on yerba mate is presented with emphasis on the importance of identity when drawing conclusions on botanicals.

3.
Dig Dis Sci ; 66(6): 1780-1790, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-32691382

RESUMO

Budd-Chiari syndrome (BCS) is an uncommon condition, caused by obstruction to hepatic venous outflow. It is largely underdiagnosed, and a high index of suspicion is required for any patient with unexplained portal hypertension. The understanding of its etiology and pathology is improving with advances in diagnostic techniques. Recent studies reported an identifiable etiology in > 80% of cases. Myeloproliferative neoplasm (MPN) is the most common etiology, and genetic studies help in diagnosing latent MPN. Better cross-sectional imaging helps delineate the site of obstruction accurately. The majority of BCS patients are now treated by endovascular intervention and anticoagulation which have improved survival in this disease. Angioplasty of hepatic veins/inferior vena cava remains under-utilized at present. While surgical porto-systemic shunts are no longer done for BCS, liver transplantation is reserved for select indications. Some of the unresolved issues in the current management of BCS are also discussed in this review.


Assuntos
Síndrome de Budd-Chiari/diagnóstico por imagem , Síndrome de Budd-Chiari/terapia , Gerenciamento Clínico , Angioplastia/tendências , Síndrome de Budd-Chiari/fisiopatologia , Procedimentos Endovasculares/tendências , Humanos , Transplante de Fígado/tendências , Terapia Trombolítica/tendências
5.
BJOG ; 127(6): 757-767, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32003141

RESUMO

OBJECTIVES: To assess the cost-effectiveness of progesterone compared with placebo in preventing pregnancy loss in women with early pregnancy vaginal bleeding. DESIGN: Economic evaluation alongside a large multi-centre randomised placebo-controlled trial. SETTING: Forty-eight UK NHS early pregnancy units. POPULATION: Four thousand one hundred and fifty-three women aged 16-39 years with bleeding in early pregnancy and ultrasound evidence of an intrauterine sac. METHODS: An incremental cost-effectiveness analysis was performed from National Health Service (NHS) and NHS and Personal Social Services perspectives. Subgroup analyses were carried out on women with one or more and three or more previous miscarriages. MAIN OUTCOME MEASURES: Cost per additional live birth at ≥34 weeks of gestation. RESULTS: Progesterone intervention led to an effect difference of 0.022 (95% CI -0.004 to 0.050) in the trial. The mean cost per woman in the progesterone group was £76 (95% CI -£559 to £711) more than the mean cost in the placebo group. The incremental cost-effectiveness ratio for progesterone compared with placebo was £3305 per additional live birth. For women with at least one previous miscarriage, progesterone was more effective than placebo with an effect difference of 0.055 (95% CI 0.014-0.096) and this was associated with a cost saving of £322 (95% CI -£1318 to £673). CONCLUSIONS: The results suggest that progesterone is associated with a small positive impact and a small additional cost. Both subgroup analyses were more favourable, especially for women who had one or more previous miscarriages. Given available evidence, progesterone is likely to be a cost-effective intervention, particularly for women with previous miscarriage(s). TWEETABLE ABSTRACT: Progesterone treatment is likely to be cost-effective in women with early pregnancy bleeding and a history of miscarriage.


Assuntos
Aborto Espontâneo/economia , Aborto Espontâneo/prevenção & controle , Progesterona/economia , Progestinas/economia , Hemorragia Uterina/tratamento farmacológico , Aborto Espontâneo/etiologia , Adolescente , Adulto , Análise Custo-Benefício , Método Duplo-Cego , Feminino , Humanos , Nascido Vivo/economia , Gravidez , Progesterona/uso terapêutico , Progestinas/uso terapêutico , Ensaios Clínicos Controlados Aleatórios como Assunto , Medicina Estatal , Resultado do Tratamento , Reino Unido , Hemorragia Uterina/complicações , Hemorragia Uterina/economia , Adulto Jovem
7.
Hum Reprod ; 34(3): 424-432, 2019 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-30776296

RESUMO

STUDY QUESTION: Does administration of recombinant human granulocyte colony stimulating factor (rhG-CSF) in the first trimester improve pregnancy outcomes, among women with a history of unexplained recurrent pregnancy loss? SUMMARY ANSWER: rhG-CSF administered in the first trimester of pregnancy did not improve outcomes among women with a history of unexplained recurrent pregnancy loss. WHAT IS KNOWN ALREADY: The only previous randomized controlled study of granulocyte colony stimulating factor in recurrent miscarriage in 68 women with unexplained primary recurrent miscarriage found a statistically significant reduction in miscarriage and improvement in live birth rates. A further four observational studies where G-CSF was used in a recurrent miscarriage population were identified in the literature, two of which confirmed statistically significant increase in clinical pregnancy and live birth rates. STUDY DESIGN, SIZE, DURATION: A randomized, double-blind, placebo controlled clinical trial involving 150 women with a history of unexplained recurrent pregnancy loss was conducted at 21 sites with established recurrent miscarriage clinics in the United Kingdom between 23 June 2014 and 05 June 2016. The study was coordinated by University of Birmingham, UK. PARTICIPANTS/MATERIALS, SETTING, METHODS: One hundred and fifty women with a history of unexplained recurrent pregnancy loss: 76 were randomized to rhG-CSF and 74 to placebo. Daily subcutaneous injections of recombinant human granulocyte - colony stimulating factor 130 µg or identical appearing placebo from as early as three to five weeks of gestation for a maximum of 9 weeks. The trial used central randomization with allocation concealment. The primary outcome was clinical pregnancy at 20 weeks of gestation, as demonstrated by an ultrasound scan. Secondary outcomes included miscarriages, livebirth, adverse events, stillbirth, neonatal birth weight, changes in clinical laboratory variables following study drug exposure, major congenital anomalies, preterm births and incidence of anti-drug antibody formation. Analysis was by intention to treat. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 340 participants were screened for eligibility of which 150 women were randomized. 76 women (median age, 32[IQR, 29-34] years; mean BMI, 26.3[SD, 4.2]) and 74 women (median age, 31[IQR, 26-33] years; mean BMI, 25.8[SD, 4.2]) were randomized to placebo. All women were followed-up to primary outcome, and beyond to live birth. The clinical pregnancy rate at 20 weeks, as well as the live birth rate, was 59.2% (45/76) in the rhG-CSF group, and 64.9% (48/74) in the placebo group, giving a relative risk of 0.9 (95% CI: 0.7-1.2; P = 0.48). There was no evidence of a significant difference between the groups for any of the secondary outcomes. Adverse events (AEs) occurred in 52 (68.4%) participants in rhG-CSF group and 43 (58.1%) participants in the placebo group. Neonatal congenital anomalies were observed in 1/46 (2.1%) of babies in the rhG-CSF group versus 1/49 (2.0%) in the placebo group (RR of 0.9; 95% CI: 0.1-13.4; P = 0.93). LIMITATIONS, REASONS FOR CAUTION: This trial was conducted in women diagnosed with unexplained recurrent pregnancy loss and therefore no screening tests (commercially available) were performed for immune dysfunction related pregnancy failure/s. WIDER IMPLICATIONS OF THE FINDINGS: To our knowledge, this is the first multicentre study and largest randomized clinical trial to investigate the efficacy and safety of granulocyte human colony stimulating factor in women with recurrent miscarriages. Unlike the only available single center RCT, our trial showed no significant increase in clinical pregnancy or live births with the use of rhG-CSF in the first trimester of pregnancy. STUDY FUNDING/COMPETING INTEREST(S): This study was sponsored and supported by Nora Therapeutics, Inc., 530 Lytton Avenue, 2nd Floor, Palo Alto, CA 94301, USA. Darryl Carter was the co-founder and VP of research, Nora Therapeutics, Inc. and held shares in the company. He holds a patent for the use of recombinant human granulocyte colony stimulating factor to reduce unexplained recurrent pregnancy loss. Mark Joing, Paul Kwon and Jeff Tong were or are employees of Nora Therapeutics, Inc. No other potential conflict of interest relevant to this article was reported. TRIAL REGISTRATION NUMBER: EUDRACT No: 2014-000084-40; ClinicalTrials.gov Identifier: NCT02156063. TRIAL REGISTRATION DATE: 31 Mar 2014. DATE OF FIRST PATIENT'S ENROLMENT: 23 Jun 2014.


Assuntos
Aborto Habitual/terapia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Adolescente , Adulto , Coeficiente de Natalidade , Método Duplo-Cego , Feminino , Humanos , Nascido Vivo , Gravidez , Resultado da Gravidez , Taxa de Gravidez , Primeiro Trimestre da Gravidez , Proteínas Recombinantes/uso terapêutico , Reino Unido , Adulto Jovem
8.
Diabet Med ; 33(3): 365-70, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26172248

RESUMO

AIMS: To assess young healthy men from rural India, who had normal or low birth weights, using magnetic resonance spectroscopy to determine the potential differences in ectopic fat storage between birth weight groups, and to determine if ectopic fat storage was associated with insulin resistance in this population. METHODS: A total of 54 lean men with normal birth weight and 49 lean men with low birth weight (age range 18-22 years) from rural India were recruited. All the men underwent anthropometry, magnetic resonance spectroscopy, a hyperinsulinaemic-euglycaemic clamp and a dual-energy X-ray absorptiometry. RESULTS: The median (interquartile range) values for hepatic cellular lipids, intramyocellular lipids and extramyocellular lipids, measured using magnetic resonance spectroscopy were 0.76 (0.1-1.8)%, 1.27 (1.0-2.3)% and 1.89 (1.3-3.2)%, respectively, for the normal birth weight group and 0.4 (0.1-1.3)%, 1.38 (0.9-2.2)% and 2.07 (1.2-2.8)%, respectively, for the low birth weight group (P > 0.05). No difference in ectopic fat storage was observed between the low and normal birth weight groups, with or without adjustment for age and total fat percentage. Homeostatic model assessment of insulin resistance values were not associated with hepatic cellular, intramyocellular or extramyocellular lipid content in any of the groups. Total fat percentage was the only independent predictor of intramyocellular and extramyocellular lipid content. CONCLUSION: Young and lean men from rural India with low birth weight were not observed to have ectopic fat storage in the liver or muscle, and the amount of liver and muscle fat was unrelated to insulin resistance. Older age and/or an urban affluent lifestyle may be required to show a potential role of ectopic fat storage on insulin resistance in Indian people with low or normal birth weight.


Assuntos
Adiposidade , Recém-Nascido de Baixo Peso/fisiologia , Resistência à Insulina/fisiologia , Fígado/metabolismo , Músculo Esquelético/metabolismo , Adolescente , Adulto , Humanos , Índia , Recém-Nascido , Metabolismo dos Lipídeos , Lipídeos/análise , Fígado/química , Espectroscopia de Ressonância Magnética , Masculino , Músculo Esquelético/química , População Rural , Adulto Jovem
9.
Food Chem Toxicol ; 55: 676-83, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-22406206

RESUMO

R,R-Monatin [2R,4R- isomer of 2-hydroxy-2-(indol-3-ylmethyl)-4-aminoglutaric acid] is one of four natural constituent isomers in the root bark of Sclerochitin ilicifolius; and "arruva" is the common/usual name that is proposed to represent R,R-monatin salt forms, which have potential use as high potency sweetener food ingredients. In the present study, groups of male and female Crl:CD-1(ICR) mice were exposed to 0 (control), 5000, 10,000, 20,000, or 35,000ppm of arruva in the diet for 90days. There were no toxicologically relevant clinical or histopathological findings in any of the test article-treated groups. Significantly lower mean body weights and cumulative body weight gains were noted in the 35,000ppm group when compared to the control group. Mean body weights in the 35,000ppm group males and females were 9% and 7% less than the control group, respectively, at week 13. In the absence of observations associated with systemic toxicity and in consideration of the magnitude of body weight difference, these effects were not considered toxicologically significant. Based on the results of this study, the dietary no-observed-adverse-effect level (NOAEL) of arruva for 90days in male and female mice was 35,000ppm (equivalent to an exposure level of 5764 and 8013mg/kg bw/day, respectively).


Assuntos
Dieta , Ácido Glutâmico/análogos & derivados , Indóis/toxicidade , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Ácido Glutâmico/administração & dosagem , Ácido Glutâmico/toxicidade , Indóis/administração & dosagem , Camundongos , Camundongos Endogâmicos ICR , Atividade Motora/efeitos dos fármacos , Tamanho do Órgão/efeitos dos fármacos
10.
Ann R Coll Surg Engl ; 94(1): e20-1, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22524914

RESUMO

Biliary papillomatosis is a rare condition usually detected on imaging or postoperative histopathology. It may be asymptomatic or present with features of cholangitis. We report the management of a patient presenting with haemobilia.


Assuntos
Neoplasias do Sistema Biliar/complicações , Colangiocarcinoma/complicações , Cisto do Colédoco/complicações , Hemobilia/etiologia , Papiloma/complicações , Neoplasias do Sistema Biliar/cirurgia , Colangiocarcinoma/cirurgia , Cisto do Colédoco/cirurgia , Feminino , Hemobilia/cirurgia , Humanos , Pessoa de Meia-Idade , Papiloma/cirurgia
11.
Food Chem Toxicol ; 49(12): 3249-57, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21925562

RESUMO

The root bark of Sclerochitin ilicifolius contains an intensely sweet substance analytically identified as isomers of 2-hydroxy-2-(indol-3-ylmethyl)-4-aminoglutaric acid and generically coined "monatin." Groups of male and female Crl:CD(SD) rats were fed 0 (control), 5000, 10,000, 20,000 or 35,000 ppm R,R-monatin salt in the diet for 90 days. There were no toxicologically relevant clinical or histopathological findings in any of the test article-treated groups. Significantly lower cumulative body weight gains were noted in the 35,000 ppm group. Mean body weights in the 35,000 ppm group males and females were 7% and 12% lower, respectively, than the control group at study week 13. In the absence of other observations associated with systemic toxicity and lower food consumption, the magnitude of the body weight difference in the 35,000 ppm group females relative to the control group exceeded 10%, which indicated attainment of a maximum tolerated dose (MTD) level. Based on the results of this study, and conservatively assuming the body weight observations at the MTD to be indicative of an adverse effect, the dietary no-observed-adverse-effect level (NOAEL) of R,R-monatin salt for 90 days was 20,000 ppm in female rats (approximately 1544 mg/kg bw/day) and 35,000 ppm in male rats (approximately 2368 mg/kg bw/day).


Assuntos
Dieta , Ácido Glutâmico/análogos & derivados , Indóis/toxicidade , Testes de Toxicidade Subcrônica/métodos , Administração Oral , Animais , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Ácido Glutâmico/administração & dosagem , Ácido Glutâmico/toxicidade , Indóis/administração & dosagem , Masculino , Nível de Efeito Adverso não Observado , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Fatores Sexuais
12.
Br J Radiol ; 83(987): e67-9, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20197432

RESUMO

Hydatid disease of the skull base is extremely rare, and intracranial extension of hydatid cysts through the skull base is even rarer. We report an interesting case of a 42-year-old man who presented with features of right vocal cord palsy. The diagnosis of hydatid cyst was made based on his history and on pre-operative MRI and was confirmed by surgery and histopathological examination.


Assuntos
Equinococose/complicações , Paralisia das Pregas Vocais/etiologia , Adulto , Albendazol/administração & dosagem , Animais , Anticestoides/administração & dosagem , Equinococose/diagnóstico , Equinococose/prevenção & controle , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Prevenção Secundária , Base do Crânio , Tomografia Computadorizada por Raios X
13.
Ann Trop Med Parasitol ; 101(4): 305-13, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17524245

RESUMO

Resistance to chloroquine (CQ) in Plasmodium falciparum is one of the main causes of the wide-spread resurgence of malaria in India and a challenge to the effective control of the disease. In the pilgrim centre of Rameswaram Island, malaria has persisted despite the various control measures undertaken over the years. When CQ resistance in Rameswaram was investigated in vivo, recrudescent parasitaemias were observed in 25 (58%) of the 43 study subjects who were given CQ and completed follow-up, all occurring between days 10 and 28 (late treatment failures). The results of the msp(1), msp(2) and glurp genotyping of paired samples of P. falciparum, collected on day 0 and the day of recrudescence from 23 of the apparent treatment failures, indicated that 21 (91%) of the 23 were probably true treatment failures. All of the paired samples harboured parasites with the K76T mutation in their pfcrt genes, and subsequent sequencing of nine day-0 samples revealed the SVMNT haplotype in all nine. This is the first report of in-vivo drug resistance in P. falciparum from Rameswaram Island. Such resistance, which is probably the result of the indiscriminate use of CQ and/or the import of malaria from mainland India, warrants a change in the drug regimen used locally for the first-line treatment of uncomplicated, P. falciparum malaria, to make treatment more effective and slow the development and spread of more foci of CQ resistance.


Assuntos
Antimaláricos/uso terapêutico , Cloroquina/uso terapêutico , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Adolescente , Adulto , Animais , Antígenos de Protozoários/genética , Criança , Pré-Escolar , Resistência a Medicamentos , Feminino , Humanos , Índia/epidemiologia , Lactente , Malária Falciparum/epidemiologia , Masculino , Proteína 1 de Superfície de Merozoito/genética , Plasmodium falciparum/genética , Proteínas de Protozoários/genética
14.
Clin Microbiol Infect ; 13(3): 331-4, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17391393

RESUMO

In total, 129 Plasmodium vivax isolates from different geographical areas in India were analysed for point mutations in the P. vivax dihydrofolate reductase gene that were associated with pyrimethamine resistance. A gradual increase in the frequency of mutant genotypes was observed from north to south (p <0.0001). In the northern region (Delhi, Panna and Nadiad), the wild-type genotype was most prevalent, while the mutant genotype predominated in the coastal regions of southern India (Navi Mumbai, Goa and Chennai). Isolates from the Car-Nicobar islands showed only mutant genotypes. The differential geographical pattern of mutations may be associated with the transmission pattern.


Assuntos
Plasmodium vivax/enzimologia , Polimorfismo Genético , Tetra-Hidrofolato Desidrogenase/genética , Alelos , Animais , Mutação , Plasmodium vivax/genética
16.
Mol Cell Biol ; 21(18): 6113-21, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11509654

RESUMO

Exposure of hematopoietic cells to DNA-damaging agents induces p53-independent cell cycle arrest at a G(1) checkpoint. Previously, we have shown that this growth arrest can be overridden by cytokine growth factors, such as erythropoietin or interleukin-3, through activation of a phosphatidylinositol 3-kinase (PI 3-kinase)/Akt-dependent signaling pathway. Here, we show that gamma-irradiated murine myeloid 32D cells arrest in G(1) with active cyclin D-cyclin-dependent kinase 4 (Cdk4) but with inactive cyclin E-Cdk2 kinases. The arrest was associated with elevated levels of the Cdk inhibitors p21(Cip1) and p27(Kip1), yet neither was associated with Cdk2. Instead, irradiation-induced inhibition of cyclin E-Cdk2 correlated with absence of the activating threonine-160 phosphorylation on Cdk2. Cytokine treatment of irradiated cells induced Cdk2 phosphorylation and activation, and cells entered into S phase despite sustained high-level expression of p21 and p27. Notably, the PI 3-kinase inhibitor, LY294002, completely blocked cytokine-induced Cdk2 activation and cell growth in irradiated 32D cells but not in nonirradiated cells. Together, these findings demonstrate a novel mechanism underlying the DNA damage-induced G(1) arrest of hematopoietic cells, that is, inhibition of Cdk2 phosphorylation and activation. These observations link PI 3-kinase signaling pathways with the regulation of Cdk2 activity.


Assuntos
Quinases relacionadas a CDC2 e CDC28 , Quinases Ciclina-Dependentes/fisiologia , Fase G1/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Serina-Treonina Quinases/fisiologia , Animais , Linhagem Celular , Quinase 2 Dependente de Ciclina , Dano ao DNA , Ativação Enzimática , Hematopoese/fisiologia , Camundongos , Transdução de Sinais
17.
Blood ; 98(3): 834-41, 2001 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-11468186

RESUMO

Exposure of hematopoietic cells to DNA-damaging agents induces cell-cycle arrest at G1 and G2/M checkpoints. Previously, it was shown that DNA damage-induced growth arrest of hematopoietic cells can be overridden by treatment with cytokine growth factors, such as erythropoietin (EPO) or interleukin-3 (IL-3). Here, the cytokine-activated signaling pathways required to override G1 and G2/M checkpoints induced by gamma-irradiation (gamma-IR) are characterized. Using factor-dependent myeloid cells stably expressing EPO receptor (EPO-R) mutants, it is shown that removal of a minimal domain required for PI-3K signaling abrogated the ability of EPO to override gamma-IR-induced cell-cycle arrest. Similarly, the ability of cytokines to override gamma-IR-induced arrest was abolished by an inhibitor of PI-3K (LY294002) or by overexpression of dominant-negative Akt. Moreover, the ability of EPO to override these checkpoints in cells expressing defective EPO-R mutants could be restored by overexpression of a constitutively active Akt. Thus, activation of a PI-3K/Akt signaling pathway is required for cytokine-dependent suppression of DNA-damage induced checkpoints. Together, these findings suggest a novel role for PI-3K/Akt pathways in the modulation of growth arrest responses to DNA damage in hematopoietic cells. (Blood. 2001;98:834-841)


Assuntos
Ciclo Celular/efeitos dos fármacos , Dano ao DNA/fisiologia , Células-Tronco Hematopoéticas/fisiologia , Fosfatidilinositol 3-Quinases/fisiologia , Proteínas Serina-Treonina Quinases , Proteínas Proto-Oncogênicas/fisiologia , Animais , Ciclo Celular/efeitos da radiação , Linhagem Celular , Ativação Enzimática , Eritropoetina/farmacologia , Raios gama , Células-Tronco Hematopoéticas/efeitos da radiação , Interleucina-3/farmacologia , Camundongos , Mutação , Fosfatidilinositol 3-Quinases/metabolismo , Fosfatidilinositol 3-Quinases/farmacologia , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Proto-Oncogênicas/farmacologia , Proteínas Proto-Oncogênicas c-akt , Receptores da Eritropoetina/genética , Transdução de Sinais/efeitos dos fármacos
18.
Cancer Res ; 61(7): 3145-50, 2001 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-11306500

RESUMO

The alternative reading frame (ARF) tumor suppressor mediates growth arrest or apoptosis through activation of the p53 tumor suppressor. A prevailing concept is that ARF uses p21Cip1/Waf1, a p53-responsive gene and cyclin-dependent kinase (Cdk) inhibitor, to block cell cycle progression. Using p21 nullizygous cells, we demonstrate that p21 is nonessential for the antiproliferative activity of ARF and p53, although it likely governs the arrest through Cdk inactivation when present. ARF overexpression in p21-positive and p21-negative mouse embryo fibroblasts (MEFs), but not in primary cells lacking p53, induced a biphasic (G1 and G2) cell cycle arrest. The ARF-induced growth arrest, regardless of p21 status, coincided with activation of p53 and accumulation of hypophosphorylated retinoblastoma protein (retinoblastoma protein). In ARF-arrested p21-positive cells, the presence of growth-inhibitory retinoblastoma protein correlated with an absence of Cdk2-dependent kinase activity, an increase in p21 association with inactive Cdks, and a lack of cyclin A expression. In contrast, p21-/- mouse embryo fibroblasts were arrested by ARF despite containing elevated levels of cyclin A protein and highly active Cdk2-dependent kinases. These findings provide evidence that ARF can block growth through a p21-independent pathway(s) that overrides Cdk2 activation.


Assuntos
Processamento Alternativo , Ciclinas/fisiologia , Genes Supressores de Tumor , Fases de Leitura/genética , Células 3T3 , Animais , Divisão Celular/fisiologia , Linhagem Celular , Inibidor de Quinase Dependente de Ciclina p21 , Quinases Ciclina-Dependentes/fisiologia , Ciclinas/genética , Ativação Enzimática , Fase G1/genética , Fase G2/genética , Humanos , Camundongos , Camundongos Knockout , Fenótipo , Fosforilação , Proteína do Retinoblastoma/metabolismo , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/fisiologia
19.
J Med Entomol ; 36(5): 595-600, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10534953

RESUMO

Female Anopheles culicifacies Giles from Ramanathapuram district, Tamil Nadu state, India, were examined for oocysts and sporozoites and their larval progeny for mitotic karyotype. Collections were made from Mandapam and Uchipuli on the mainland, and Thangachimadam and Pamban on Rameshwaram Island. Of the 451 An. culicifacies females that were collected and dissected, 24 were found positive for Plasmodia (21 for sporozoites and 3 for oocysts). Both acrocentric and submetacentric Y-chromosome karyotypes were observed among the progeny of females from all villages. All 11 iso-female lines whose parental females were positive for sporozoites or oocysts had progeny with submetacentric Y-chromosomes. Total absence of sporozoite-positives among mothers of acrocentric males was evidence of assortative mating between these 2 sympatric populations (i.e., 2 species). We propose that the nonvector population with acrocentric Y-chromosome sons retain the original designation of species B and that the vector population with the submetacentric Y-chromosome sons be designated as species E, a new species.


Assuntos
Anopheles/parasitologia , Insetos Vetores/parasitologia , Malária/transmissão , Plasmodium vivax , Animais , Anopheles/genética , Feminino , Insetos Vetores/genética , Masculino
20.
Indian J Malariol ; 35(3): 160-2, 1998 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10497842

RESUMO

Efficacy of Plasmodium falciparum histidine-rich protein (HRP-II) based diagnostic test ParaSight-F, was evaluated for diagnosis of P. falciparum malaria at the Malaria Clinic in Malaria Research Centre (Field Station), Chennai, Tamil Nadu. A total of 93 febrile patients were screened in parallel by microscopy and by ParaSight-F. The sensitivity and specificity of the test were 100% for the detection of P. falciparum infection.


Assuntos
Malária Falciparum/diagnóstico , Plasmodium falciparum/isolamento & purificação , Proteínas/análise , Proteínas de Protozoários/análise , Animais , Estudos de Avaliação como Assunto , Humanos , Índia , Malária Falciparum/parasitologia , Proteínas/imunologia , Proteínas de Protozoários/imunologia , Kit de Reagentes para Diagnóstico , Sensibilidade e Especificidade
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