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1.
PLoS One ; 17(3): e0264785, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35298502

RESUMO

The variability of clinical course and prognosis of COVID-19 highlights the necessity of patient sub-group risk stratification based on clinical data. In this study, clinical data from a cohort of Indian COVID-19 hospitalized patients is used to develop risk stratification and mortality prediction models. We analyzed a set of 70 clinical parameters including physiological and hematological for developing machine learning models to identify biomarkers. We also compared the Indian and Wuhan cohort, and analyzed the role of steroids. A bootstrap averaged ensemble of Bayesian networks was also learned to construct an explainable model for discovering actionable influences on mortality and days to outcome. We discovered blood parameters, diabetes, co-morbidity and SpO2 levels as important risk stratification features, whereas mortality prediction is dependent only on blood parameters. XGboost and logistic regression model yielded the best performance on risk stratification and mortality prediction, respectively (AUC score 0.83, AUC score 0.92). Blood coagulation parameters (ferritin, D-Dimer and INR), immune and inflammation parameters IL6, LDH and Neutrophil (%) are common features for both risk and mortality prediction. Compared with Wuhan patients, Indian patients with extreme blood parameters indicated higher survival rate. Analyses of medications suggest that a higher proportion of survivors and mild patients who were administered steroids had extreme neutrophil and lymphocyte percentages. The ensemble averaged Bayesian network structure revealed serum ferritin to be the most important predictor for mortality and Vitamin D to influence severity independent of days to outcome. The findings are important for effective triage during strains on healthcare infrastructure.


Assuntos
COVID-19/mortalidade , Hospitalização/estatística & dados numéricos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Teorema de Bayes , COVID-19/epidemiologia , COVID-19/etiologia , Criança , China/epidemiologia , Feminino , Humanos , Índia/epidemiologia , Aprendizado de Máquina , Masculino , Pessoa de Meia-Idade , Modelos Estatísticos , Medição de Risco/métodos , Fatores de Risco , Adulto Jovem
2.
Int J Obstet Anesth ; 45: 67-73, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33298343

RESUMO

INTRODUCTION: Shock index and continuous non-invasive haemoglobin monitoring (SpHb) have both been proposed for the timely recognition of postpartum haemorrhage (PPH). We sought to determine, in parallel, the association of each of shock index and SpHb with blood loss after vaginal delivery. METHODS: Sixty-six women were recruited to this prospective observational study. Shock index and SpHb were recorded postpartum for 120 min. The association between each of shock index and SpHb with quantitative blood loss (QBL) at 30, 60 and 120 min postpartum was determined using linear mixed models. Area-under-the-receiver-operator-characteristic (AUROC) curves were constructed to evaluate the diagnostic ability of shock index and SpHb to detect PPH (defined as QBL ≥1000 mL). RESULTS: Shock index trend was associated with QBL over the first 30 min (r=0.37, P=0.002), but not over 60 or 120 min. There was an association of SpHb trend with QBL over the first 30 min (P=0.06), but not over 60 min (r=-0.32, P=0.009) or 120 min (r=-0.26, P=0.03). Maximum shock index within 60 min correlated with QBL (r=0.54, P <0.001) and was a predictor of PPH (P=0.0012, AUROC 0.796). Maximum change in SpHb within 60 min negatively correlated with QBL (r=-0.4, P <0.001) and was a predictor of PPH (P=0.048, AUROC 0.761). CONCLUSIONS: The trend of shock index and its peak values are associated with blood loss after vaginal delivery and are early indicators of PPH. Negative trend of SpHb is a late sign of PPH and has a weaker association with blood loss than shock index.


Assuntos
Hemorragia Pós-Parto , Parto Obstétrico , Feminino , Hemoglobinas/análise , Humanos , Projetos Piloto , Hemorragia Pós-Parto/diagnóstico , Gravidez , Estudos Prospectivos
3.
J Thromb Haemost ; 16(7): 1296-1306, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29723935

RESUMO

Essentials Risk of intracranial hemorrhage (ICH) may differ between direct oral anticoagulants (DOACs). We compared the risk of ICH between DOACs using network meta-analysis. Dabigatran 110 mg and 150 mg were safer than rivaroxaban on Bayesian analysis. Dabigatran 110 mg ranked as the safest DOAC while rivaroxaban ranked last. SUMMARY: Background The comparative risk of intracranial hemorrhage (ICH) among direct oral anticoagulants (DOACs) (dabigatran, rivaroxaban, apixaban and edoxaban) remains unclear. Objective To determine the difference in risk of ICH between DOACs Methods Seventeen randomized controlled trials (RCTs) were selected using PubMed/MEDLINE, EMBASE and CENTRAL (Inception, 31 December 2017). Estimates were reported as odds ratio (OR) with 95% credible interval (CR.I) in Bayesian network meta-analysis (NMA), and OR with 95% confidence interval (CI) in traditional meta-analyses. Relative ranking probability of each group was generated based on surface under the cumulative ranking curve (SUCRA). Results In NMA of 116 618 patients from 17 RCTs (apixaban = 19 495 patients, rivaroxaban = 14 157 patients, dabigatran = 16 074 patients, edoxaban = 11 652 patients, and comparator = 55 315 patients), all DOACs were safer than warfarin for risk of ICH. Dabigatran 110 mg ranked as the safest drug (SUCRA, 0.85) and reduced the risk of ICH by 56% compared to rivaroxaban (OR, 0.44; 95% Cr.I, 0.22-0.82). Pairwise meta-analysis validated these findings, showing that DOACs were safer than warfarin (OR, 0.46; 95% CI, 0.35-0.59). Subgroup analysis showed that the benefit was present when DOACs were used in non-valvular atrial fibrillation (NVAF) (OR, 0.51; 95% CI, 0.38-0.68) or venous thromboembolism (VTE) (OR, 0.32; 95% CI, 0.18-0.58). Conclusion Dabigatran 110 mg may be the safest choice among any anticoagulant regarding risk of ICH. Both dabigatran 110 mg and 150 mg were safer than rivaroxaban.


Assuntos
Antitrombinas/administração & dosagem , Antitrombinas/efeitos adversos , Inibidores do Fator Xa/administração & dosagem , Inibidores do Fator Xa/efeitos adversos , Hemorragias Intracranianas/induzido quimicamente , Administração Oral , Teorema de Bayes , Dabigatrana/administração & dosagem , Dabigatrana/efeitos adversos , Humanos , Hemorragias Intracranianas/diagnóstico , Pirazóis/administração & dosagem , Pirazóis/efeitos adversos , Piridinas/administração & dosagem , Piridinas/efeitos adversos , Piridonas/administração & dosagem , Piridonas/efeitos adversos , Medição de Risco , Fatores de Risco , Rivaroxabana/administração & dosagem , Rivaroxabana/efeitos adversos , Tiazóis/administração & dosagem , Tiazóis/efeitos adversos , Resultado do Tratamento
4.
Neoplasia ; 19(12): 1003-1011, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-29121598

RESUMO

Advanced head and neck squamous cell carcinoma (HNSCC) remains a therapeutic challenge due to the development of therapy resistance. Several studies have implicated the development of cancer stem cells as a possible mechanism for therapy resistance in HNSCC. Heat shock protein 90's (Hsp90's) molecular chaperone function is implicated in pathways of resistance in HNSCC. Therefore, in the present study, we investigated the efficacy of novel C-terminal Hsp90 inhibitors (KU711 and KU757) in targeting HNSCC cancer stem cells (CSCs). Treatment of HNSCC human cell lines MDA1986, UMSCC 22B, and UMSCC 22B cisplatin-resistant cells with the KU compounds indicated complete blockage of self-renewal for the resistant and parent cell lines starting from 20 µM KU711 and 1 µM KU757. Dose-dependent decrease in the cancer stem cell markers CD44, ALDH, and CD44/ALDH double-positive cells was observed for all cell lines after treatment with KU711 and KU757. When cells were treated with either drug, migration and invasion were downregulated greater than 90% even at the lowest concentrations of 20 µM KU711 and 1 µM KU757. Western blot showed >90% reduction in client protein "stemness" marker BMI-1 and mesenchymal marker vimentin, as well as increase in epithelial marker E-cadherin for both cell lines, indicating epithelial to mesenchymal transition quiescence. Several CSC-mediated miRNAs that play a critical role in HNSCC therapy resistance were also downregulated with KU treatment. In vivo, KU compounds were effective in decreasing tumor growth with no observed toxicity. Taken together, these results indicate that KU compounds are effective therapeutics for targeting HNSCC CSCs.


Assuntos
Antineoplásicos/farmacologia , Carcinoma de Células Escamosas/metabolismo , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Neoplasias de Cabeça e Pescoço/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/metabolismo , Domínios e Motivos de Interação entre Proteínas/efeitos dos fármacos , Animais , Biomarcadores , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Autorrenovação Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Modelos Animais de Doenças , Resistencia a Medicamentos Antineoplásicos , Regulação Neoplásica da Expressão Gênica , Proteínas de Choque Térmico HSP90/química , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/patologia , Humanos , Camundongos , MicroRNAs/genética , Transdução de Sinais , Carcinoma de Células Escamosas de Cabeça e Pescoço , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
5.
Indian J Surg ; 77(Suppl 1): 72-4, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25972650

RESUMO

Vascular malformations are rare congenital vascular anomalies composed of inappropriately connected vasculature. They are usually present at birth, are progressive, infiltrative and require intervention. Vascular malformations need to be differentiated from haemangiomas which are congenital vascular neoplasms. We present a case of vascular malformation in a 6-year old child who presented with a progressive swelling in the neck and was treated by surgical excision. This case is being presented because of its peculiar clinical presentation.

6.
Heredity (Edinb) ; 115(3): 188-94, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25853517

RESUMO

Phosphine (PH3) fumigation is the primary method worldwide for controlling insect pests of stored commodities. Over-reliance on phosphine, however, has led to the emergence of strong resistance. Detailed genetic studies previously identified two loci, rph1 and rph2, that interact synergistically to create a strong resistance phenotype. We compared the genetics of phosphine resistance in strains of Rhyzopertha dominica and Tribolium castaneum from India and Australia, countries having similar pest species but widely differing in pest management practices. Sequencing analysis of the rph2 locus, dihydrolipoamide dehydrogenase (dld), identified two structurally equivalent variants, Proline49>Serine (P49S) in one R. dominica strain and P45S in three strains of T. castaneum from India. These variants of the DLD protein likely affect FAD cofactor interaction with the enzyme. A survey of insects from storage facilities across southern India revealed that the P45/49S variant is distributed throughout the region at very high frequencies, in up to 94% of R. dominica and 97% of T. castaneum in the state of Tamil Nadu. The abundance of the P45/49S variant in insect populations contrasted sharply with the evolutionary record in which the variant was absent from eukaryotic DLD sequences. This suggests that the variant is unlikely to provide a strong selective advantage in the absence of phosphine fumigation.


Assuntos
Besouros/genética , Di-Hidrolipoamida Desidrogenase/genética , Proteínas de Insetos/genética , Resistência a Inseticidas/genética , Fosfinas , Animais , Austrália , Besouros/enzimologia , Evolução Molecular , Armazenamento de Alimentos , Fumigação , Frequência do Gene , Índia , Inseticidas , Polimorfismo de Nucleotídeo Único , Análise de Sequência de DNA , Tribolium/enzimologia , Tribolium/genética
9.
Indian J Gastroenterol ; 25(1): 37-8, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16567894

RESUMO

A 47-year-old man presented with epigastric pain relieved by bilious vomiting since one month. He had undergone truncal vagotomy with posterior gastrojejunostomy for benign gastric outlet obstruction 2 years ago. Endoscopy showed distension and stasis in the afferent loop, bile gastritis and esophagitis. Laparoscopic Braun jejunojejunostomy relieved his symptoms.


Assuntos
Síndromes Pós-Gastrectomia/diagnóstico , Síndromes Pós-Gastrectomia/cirurgia , Gastrectomia/efeitos adversos , Obstrução da Saída Gástrica/cirurgia , Humanos , Jejunostomia/efeitos adversos , Jejunostomia/métodos , Masculino , Pessoa de Meia-Idade , Estenose Pilórica/cirurgia , Vagotomia Troncular
10.
Surg Endosc ; 20(1): 61-3, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16333531

RESUMO

BACKGROUND: The aim of this study is to highlight the role of minimally invasive surgery in the form of laparoscopy-assisted truncal vagotomy (TV) with ante-colic posterior gastrojejunostomy (PGJ) for benign gastric outlet obstruction (GOO). GOO is relatively common in southern India due to various factors. From 1994 to 2004, 762 patients with GOO were operated on (open TV with PGJ) in our center. METHODS: From November 2003 to November 2004, 18 patients with GOO underwent the laparoscopic procedure in our unit. The procedure involves laparoscopic TV followed by the ante-colic PGJ performed extracorporeally through a 3.5-cm transverse incision in the upper abdomen. RESULTS: The advantages of this procedure are that pain, hospital stay, size of wound, incidence of incisional hernia, and postoperative complications are reduced and the patient returns to work earlier. The results are comparable to those of a totally laparoscopic TV with PGJ. CONCLUSION: This procedure is relatively easy to perform because the anastomosis is done extracorporeally, and it is less expensive than the use of endostaplers. Thus, more surgeons should be encouraged to perform laparoscopic TV with PGJ.


Assuntos
Obstrução da Saída Gástrica/patologia , Obstrução da Saída Gástrica/cirurgia , Gastroenterostomia , Laparoscopia , Procedimentos Cirúrgicos Minimamente Invasivos , Vagotomia Troncular/métodos , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do Tratamento
11.
Acta Paediatr ; 91(9): 1005-7, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12412881

RESUMO

UNLABELLED: Posterior leukoencephalopathy syndrome is characterized by an acute, usually reversible, encephalopathy with transient occipital lobe abnormalities detected on MRI that occur mostly in association with acute hypertension. The clinical presentation includes seizures, headache, altered mental status and blindness. Disturbed autoregulation of cerebral blood flow and endothelial injury are central to the pathogenesis of this disorder. Prompt control of hypertension results in rapid and complete neurological recovery. In this report we discuss the cases of two children with acute onset hypertension of different aetiologies that presented with the characteristic features of posterior leukoencephalopathy syndrome. CONCLUSION: Early recognition of this readily treatable condition may obviate the need for extensive and invasive investigations. Despite the alarming lesions on the MRI, prompt control of hypertension carries a uniformly favourable prognosis.


Assuntos
Edema Encefálico/diagnóstico , Encéfalo/patologia , Epilepsia Generalizada/diagnóstico , Hipertensão Maligna/diagnóstico , Imageamento por Ressonância Magnética , Lobo Occipital/patologia , Doença Aguda , Anticonvulsivantes/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Edema Encefálico/complicações , Edema Encefálico/tratamento farmacológico , Criança , Pré-Escolar , Quimioterapia Combinada , Epilepsia Generalizada/complicações , Epilepsia Generalizada/tratamento farmacológico , Humanos , Hipertensão Maligna/complicações , Hipertensão Maligna/tratamento farmacológico , Masculino , Lobo Occipital/fisiopatologia , Prognóstico , Medição de Risco , Índice de Gravidade de Doença , Síndrome , Resultado do Tratamento
13.
Biochemistry ; 41(6): 1934-46, 2002 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-11827540

RESUMO

Toc34 is a transmembrane protein located in the outer envelope membrane of chloroplasts and involved in transit peptide recognition. The cytosolic region of Toc34 reveals 34% alpha-helical and 26% beta-strand structure and is stabilized by intramolecular electrostatic interaction. Toc34 binds both chloroplast preproteins and isolated transit peptides in a guanosine triphosphate- (GTP-) dependent mechanism. In this study we demonstrate that the soluble, cytosolic domain of Toc34 (Toc34deltaTM) functions as receptor in vitro and is capable to compete with the import of the preprotein of the small subunit (preSSU) of ribulose-1,5-bisphosphate carboxylase-oxygenase into chloroplasts in a GTP-dependent manner. We have developed a biosensor assay to study the interaction of Toc34deltaTM with purified preproteins and transit peptides. The results are compared with the interactions of both a full-size preprotein and the transit peptide of preSSU with the translocon of the outer envelope of chloroplasts (Toc complex) in situ. Several mutants of the transit peptide of preSSU were evaluated to identify amino acid segments that are specifically recognized by Toc34. We present a model of how Toc34 may recognize the transit peptide and discuss how this interaction may facilitate interaction and translocation of preproteins via the Toc complex in vivo.


Assuntos
Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Proteínas de Plantas , Sequência de Aminoácidos , Técnicas Biossensoriais , Proteínas de Transporte/metabolismo , Cloroplastos/metabolismo , Citosol/química , Precursores Enzimáticos/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Cinética , Proteínas de Membrana/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Fosforilação , Ligação Proteica , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Ribulose-Bifosfato Carboxilase/metabolismo , Deleção de Sequência
14.
J Virol ; 75(19): 9446-57, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11533207

RESUMO

The latency-associated nuclear antigen (LANA) encoded by the Kaposi's sarcoma-associated herpesvirus (KSHV) is expressed in the majority of KSHV-infected cells and in cells coinfected with Epstein-Barr virus (EBV). In coinfected body cavity-based lymphomas (BCBLs), EBV latent membrane protein 1 (LMP1), which is essential for B-lymphocyte transformation, is expressed. EBNA2 upregulates the expression of LMP1 and other cellular genes through specific interactions with cellular transcription factors tethering EBNA2 to its responsive promoters. In coinfected BCBL cells, EBNA2 is not detected but LANA, which is constitutively expressed, contains motifs suggestive of potential transcriptional activity. Additionally, recent studies have shown that LANA is capable of activating cellular promoters. Therefore, we investigated whether LANA can affect transcription from two major EBV latent promoters. In this study, we demonstrated that LANA can efficiently transactivate both the LMP1 and C promoters in the human B-cell line BJAB as well as in the human embryonic kidney 293 cell line. Moreover, we demonstrated that specific domains of LANA containing the putative leucine zipper and the glutamic acid-rich region are highly effective in upregulating these viral promoters, while the amino-terminal region (435 amino acids) exhibited little or no transactivation activity in our assays. We also specifically tested truncations of the LMP1 promoter element and showed that the -204 to +40 region had increased levels of activation compared with a larger region, -512 to +40, which contains two recombination signal-binding protein J kappa binding sites. The smaller, -204 to +40 promoter region contains specific binding sites for the Ets family transcription factor PU.1, transcription activating factor/cyclic AMP response element, and Sp1, all of which are known to function as activators of transcription. Our data therefore suggest a potential role for LANA in regulation of the major EBV latent promoters in KSHV- and EBV-coinfected cells. Furthermore, LANA may be able to activate transcription of viral and cellular promoters in the absence of EBNA2, potentially through association with transcription factors bound to their cognate sequences within the -204 to +40 region. This regulation of viral gene expression is critical for persistence of these DNA tumor viruses and most likely involved in mediating the oncogenic process in these coinfected cells.


Assuntos
Herpesvirus Humano 4/genética , Herpesvirus Humano 8/fisiologia , Proteínas Nucleares/fisiologia , Antígenos Virais/fisiologia , Linhagem Celular , Regulação Viral da Expressão Gênica , Humanos , Ativação Transcricional , Latência Viral/genética , Replicação Viral
15.
J Virol ; 75(18): 8556-68, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11507201

RESUMO

Epstein-Barr virus (EBV) is associated with human cancers, including nasopharyngeal carcinoma, Burkitt's lymphoma, gastric carcinoma and, somewhat controversially, breast carcinoma. EBV infects and efficiently transforms human primary B lymphocytes in vitro. A number of EBV-encoded genes are critical for EBV-mediated transformation of human B lymphocytes. In this study we show that an EBV-infected lymphoblastoid cell line obtained from the spontaneous outgrowth of B cells from a leukemia patient contains a deletion, which involves a region of approximately 16 kbp. This deletion encodes major EBV genes involved in both infection and transformation of human primary B lymphocytes and includes the glycoprotein gp350, the entire open reading frame of EBNA3A, and the amino-terminal region of EBNA3B. A fusion protein created by this deletion, which lies between the BMRF1 early antigen and the EBNA3B latent antigen, is truncated immediately downstream of the junction 21 amino acids into the region of the EBNA3B sequence, which is out of frame with respect to the EBNA3B protein sequence, and indicates that EBNA3B is not expressed. The fusion is from EBV coordinate 80299 within the BMRF1 sequence to coordinate 90998 in the EBNA3B sequence. Additionally, we have shown that there is no detectable induction in viral replication observed when SNU-265 is treated with phorbol esters, and no transformants were detected when supernatant is used to infect primary B lymphocytes after 8 weeks in culture. Therefore, we have identified an EBV genome with a major deletion in critical genes involved in mediating EBV infection and the transformation of human primary B lymphocytes that is incompetent for replication of this naturally occurring EBV isolate.


Assuntos
Antígenos Nucleares do Vírus Epstein-Barr/genética , Herpesvirus Humano 4/genética , Glicoproteínas de Membrana/genética , Deleção de Sequência , Proteínas da Matriz Viral/genética , Animais , Linfócitos B/citologia , Southern Blotting/métodos , Western Blotting/métodos , Callithrix , Linhagem Celular , Desoxirribonuclease BamHI , Antígenos Nucleares do Vírus Epstein-Barr/biossíntese , Genoma Viral , Herpesvirus Humano 4/isolamento & purificação , Humanos , Fases de Leitura Aberta , Ésteres de Forbol , Reação em Cadeia da Polimerase/métodos
16.
J Virol ; 75(18): 8761-71, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11507221

RESUMO

The latency-associated nuclear antigen (LANA) is constitutively expressed in cells infected with the Kaposi's sarcoma (KS) herpesvirus (KSHV), also referred to as human herpesvirus 8. KSHV is tightly associated with body cavity-based lymphomas (BCBLs) in immunocompromised patients infected with human immunodeficiency virus (HIV). LANA, encoded by open reading frame 73 of KSHV, is one of a small subset of proteins expressed during latent infection and was shown to be important in tethering the viral episome to host chromosomes. Additionally, it has been shown that LANA can function as a regulator of transcription. However, its role in the progression of disease is still being elucidated. Since KS is one of the most common AIDS-associated cancers in the United States and BCBLs appear predominantly in AIDS patients, we examined whether LANA is able to regulate the HIV type 1 (HIV-1) long terminal repeat (LTR). Using luciferase-based transient transfection assays, we found that LANA was able to transactivate the HIV-1 LTR in the human B-cell line BJAB, human monocytic cell line U937, and the human embryonic kidney fibroblast cell line 293T. Moreover, we observed that the virus-encoded HIV transactivator protein Tat cooperated with LANA in activation of the LTR in a dose-response fashion with increasing amounts of LANA. Surprisingly, LANA alone was sufficient to transactivate the HIV-1 LTR in BJAB cells. In similar assays using a HIV-1 LTR construct with the core enhancer elements deleted; the activity of LANA was diminished but not abolished, indicating a mechanism which involves the cooperation of the core enhancer elements and downstream elements which include Tat. Furthermore, transient transfection of an infectious clone of HIV with LANA demonstrated effects similar to those seen in the reporter assays based on Western blot analysis of HIV Gag polypeptide p24. Interestingly, we also demonstrated that the carboxy terminus of LANA associates with Tat in cells and in vitro. These experiments suggest a role for LANA in activating the HIV-1 LTR through association with cellular molecules targeting the core enhancer elements and Tat and may have important consequences in increasing the levels of HIV in infected individuals and, hence, the disease state.


Assuntos
Produtos do Gene tat/metabolismo , Repetição Terminal Longa de HIV , HIV-1/metabolismo , Herpesvirus Humano 8/metabolismo , Proteínas Nucleares/metabolismo , Antígenos Virais , Linhagem Celular , Linhagem Celular Transformada , Núcleo Celular/metabolismo , Proteína do Núcleo p24 do HIV/biossíntese , HIV-1/fisiologia , Herpesvirus Humano 8/genética , Humanos , Proteínas Nucleares/genética , Ativação Transcricional , Transfecção , Células U937 , Latência Viral , Produtos do Gene tat do Vírus da Imunodeficiência Humana
17.
Indian J Pediatr ; 68(3): 267-72, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11338225

RESUMO

Tetanus is an acute neurological disease characterized by muscle rigidity and spasms, autonomic dysfunction and in severe forms requires respiratory and hemodynamic support. Though it is entirely preventable by immunization, it still occurs in developing countries causing significant morbidity and mortality. Intensive care management of tetanus is fraught with problems of ventilator-associated pneumonia, nosocomial sepsis and a variety of other complications. Various treatment protocols have been tried in managing diverse manifestations of severe tetanus but the consensus is yet to emerge. In this review we have discussed the pathophysiology, clinical features and management controversies and suggest on basis of our experience use of high dose diazepam (20-120 mg/kg/day) and vecuronium with mechanical ventilation if required for control of spasms, and early detection of autonomic dysfunction and use of propranolol, in our circumstances.


Assuntos
Tétano/terapia , Criança , Pré-Escolar , Cuidados Críticos , Diazepam/uso terapêutico , Feminino , Humanos , Masculino , Relaxantes Musculares Centrais/uso terapêutico
18.
Nat Med ; 7(3): 350-5, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11231635

RESUMO

Epstein-Barr virus (EBV) is an oncogenic virus associated with a number of human malignancies including Burkitt lymphoma, nasopharyngeal carcinoma, lymphoproliferative disease and, though still debated, breast carcinoma. A subset of latent EBV antigens is required for mediating immortalization of primary B-lymphocytes. Here we demonstrate that the carboxy-terminal region of the essential latent antigen, EBNA-3C, interacts specifically with the human metastatic suppressor protein Nm23-H1. Moreover, EBNA-3C reverses the ability of Nm23-H1 to suppress the migration of Burkitt lymphoma cells and breast carcinoma cells. We propose that EBNA-3C contributes to EBV-associated human cancers by targeting and altering the role of the metastasis suppressor Nm23-H1.


Assuntos
Antígenos Virais/metabolismo , Herpesvirus Humano 4/imunologia , Proteínas Monoméricas de Ligação ao GTP/metabolismo , Metástase Neoplásica , Núcleosídeo-Difosfato Quinase , Fatores de Transcrição/metabolismo , Sequência de Bases , Núcleo Celular/metabolismo , Primers do DNA , Humanos , Nucleosídeo NM23 Difosfato Quinases , Ligação Proteica , Células Tumorais Cultivadas
19.
Plant J ; 25(3): 349-63, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11208026

RESUMO

Chloroplast transit peptides are necessary and sufficient for the targeting and translocation of precursor proteins across the chloroplast envelope. However, the mechanism by which transit peptides engage the translocation apparatus has not been investigated. To analyse this interaction, we have developed a novel epitope-tagged transit peptide derived from the precursor of the small subunit of pea Rubisco. The recombinant transit peptide, His-S-SStp, contains a removable dual-epitope tag, His-S, at its N-terminus that permits both rapid purification via immobilized metal affinity chromatography and detection by blotting, flow cytometry and laser-scanning confocal microscopy. Unlike other chimeric precursors, which place the passenger protein C-terminal to the transit peptide, His-S-SStp bound to the translocation apparatus yet did not translocate across the chloroplast envelope. This early translocation intermediate allowed non-radioactive detection using fluorescent and chemiluminescent reporters. The physiological relevance of this interaction was confirmed by protein import competitions, sensitivity to pre- and post-import thermolysin treatment, photochemical cross-linking and organelle fractionation. The interaction was specific for the transit peptide since His-S alone did not engage the chloroplast translocation apparatus. Quantitation of the bound transit peptide was determined by flow cytometry, showing saturation of binding yet only slight ATP-dependence. The addition of GTP showed inhibition of the binding of His-S-SStp to the chloroplasts indicating an involvement of GTP in the formation of this early translocation intermediate. In addition, direct visualization of His-S-SStp and Toc75 by confocal microscopy revealed a patch-like labeling, suggesting a co-ordinate localization to discrete regions on the chloroplast envelope. These findings represent the first direct visualization of a transit peptide interacting with the chloroplast translocation apparatus. Furthermore, identification of a chloroplast-binding intermediate may provide a novel tool to dissect interactions between a transit peptide and the chloroplast translocation apparatus.


Assuntos
Cloroplastos/metabolismo , Precursores Enzimáticos/metabolismo , Epitopos/metabolismo , Peptídeos/metabolismo , Proteínas de Plantas , Proteínas Recombinantes/metabolismo , Sequência de Aminoácidos , Transporte Biológico , Clonagem Molecular , Precursores Enzimáticos/química , Citometria de Fluxo , Guanosina Trifosfato/metabolismo , Microscopia Confocal , Dados de Sequência Molecular , Proteínas Recombinantes/química , Termolisina/farmacologia
20.
J Biol Chem ; 276(3): 1794-9, 2001 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-11036085

RESUMO

Prothymosin alpha (ProTalpha), a cellular molecule known to be associated with cell proliferation, is transcriptionally up-regulated on expression of c-myc and interacts with histones in vitro and associates with histone H1 in cells. Previous studies have also shown that ProTalpha is involved in chromatin remodeling. Recent studies have shown that ProTalpha interacts with the acetyl transferase p300 and an essential Epstein-Barr virus protein, EBNA3C, involved in regulation of viral and cellular transcription. These studies suggest a potential involvement in regulation of histone acetylation through the association with these cellular and viral factors. In the current studies, we show that heterologous expression of ProTalpha in the Rat-1 rodent fibroblast cell line results in increased proliferation, loss of contact inhibition, anchorage-independent growth, and decreased serum dependence. These phenotypic changes seen in transfected Rat-1 cells are similar to those observed with a known oncoprotein, Ras, expressed under the control of a heterologous promoter and are characteristic oncogenic growth properties. These results demonstrate that the ProTalpha gene may function as an oncogene when stably expressed in Rat-1 cells and may be an important downstream cellular target for inducers of cellular transformation, which may include Epstein-Barr virus and c-myc.


Assuntos
Transformação Celular Neoplásica , Proteínas Oncogênicas/fisiologia , Precursores de Proteínas/fisiologia , Timosina/fisiologia , Animais , Sequência de Bases , Linhagem Celular , Primers do DNA , Fibroblastos/citologia , Regiões Promotoras Genéticas , Ratos , Timosina/análogos & derivados , Transfecção
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