RESUMO
Atovaquone (AV) acts on the malaria parasite by competing with ubiquinol (UQH2) for its union to the mitochondrial bc1 complex, preventing the ubiquinone-8 and ubiquinone-9 (UQ-8 and UQ-9) redox recycling, which is a necessary step in pyrimidine biosynthesis. This study focused on UQ biosynthesis in Plasmodium falciparum and adopted proof-of-concept research to better elucidate the mechanism of action of AV and improve its efficacy. Initially, UQ biosynthesis was evaluated using several radioactive precursors and chromatographic techniques. This methodology was suitable for studying the biosynthesis of both UQ homologs and its redox state. Additionally, the composition of UQ was investigated in parasites cultivated at different oxygen saturations or in the presence of AV. AV affected the redox states of both UQ-8 and UQ-9 homologs by increasing the levels of the respective reduced forms. Conversely, low-oxygen environments specifically inhibited UQ-9 biosynthesis and increased the antimalarial efficacy of AV. These findings encouraged us to investigate the biological importance and the potential of UQ biosynthesis as a drug target based on its inhibition by 4-nitrobenzoate (4-NB), a 4-hydroxybenzoate (4-HB) analog. 4-NB effectively inhibits UQ biosynthesis and enhances the effects of AV on parasitic growth and respiration rate. Although 4-NB itself exhibits poor antimalarial activity, its 50% inhibitory concentration (IC50) value increased significantly in the presence of a soluble UQ analog, p-aminobenzoic acid (pABA), or 4-HB. These results indicate the potential of AV combined with 4-NB as a novel therapy for malaria and other diseases caused by AV-sensitive pathogens.
Assuntos
Malária , Ubiquinona , Atovaquona/farmacologia , Humanos , Mitocôndrias/metabolismo , Oxirredução , Ubiquinona/metabolismoRESUMO
WHAT IS KNOWN AND OBJECTIVES: Patients undergoing Roux-en-Y gastric bariatric (RYGB) surgery present a reduced absorption site, and special attention should therefore be taken when prescribing oral-dosage forms. This study was carried out to investigate the extent to which non-bariatric clinicians are aware of this issue when prescribing medicines for this population, and what type of information is available to aid them in their decision-making. METHODS: Two questionnaires were created, one for non-bariatric clinicians and another for their patients who had undergone RYGB surgery, to gather information about the prescription practices for this population. Additionally, a literature search of pharmacokinetic studies on bariatric patients and recommended prescription practices was carried out. RESULTS AND DISCUSSION: Of the 62 non-bariatric clinicians surveyed, 50% believed RYGB surgery interferes with drug absorption; however, 68% still prescribed tablets as the first choice form of dosage. Young clinicians (35%) were less likely to believe that RYGB surgery could affect drug absorption than experienced clinicians (43%). The main reasons for changing dosage forms were patient complaints about efficacy or difficulty in swallowing tablets. Of the 73 patients, 43 were taking drugs in tablet form after the surgery, 24 of whom had health issues unrelated to the surgery. None of the journals read by the clinicians contained pharmacokinetics (PK) studies involving bariatric surgery patients or presented recommendations for the prescription of oral-dosage forms for this population. The literature search revealed a total of 22 drugs that had undergone PK studies in RYGB patients. Fifteen of them were reported to have decreased effects, 12 of which were administered as tablets. WHAT IS NEW AND CONCLUSION: There is still a relative lack of clinical evidence to guide clinicians when prescribing medicines for bariatric patients. It is therefore recommended that pharmacists should have greater participation in the prescription process to advise non-bariatric clinicians and educate RYGB surgery patients to help avoid therapeutic failure.
Assuntos
Cirurgia Bariátrica , Prescrições de Medicamentos/estatística & dados numéricos , Papel do Médico , Cuidados Pós-Operatórios/métodos , Padrões de Prática Médica/estatística & dados numéricos , Administração Oral , Adulto , Aconselhamento , Feminino , Humanos , Masculino , Absorção pela Mucosa Oral , Período Pós-Operatório , Inquéritos e QuestionáriosRESUMO
We describe here a new frameshift mutation of ß-thalassemia in a Uruguayan family with Italian ancestry [ß48 (-T); HBB:c.146delT]. This frameshift results in formation of premature stop codon (TGA) 40 bp downstream and in a short unstable product that is degraded in the cell.
Assuntos
Saúde da Família , Mutação da Fase de Leitura , Globinas beta/genética , Talassemia beta/genética , Adulto , Códon sem Sentido , Éxons , Feminino , Deleção de Genes , Heterozigoto , Humanos , Itália , Linhagem , Estabilidade Proteica , Uruguai , População Branca , Globinas beta/análise , Globinas beta/metabolismo , Talassemia beta/sangue , Talassemia beta/metabolismoRESUMO
MicroRNAs (miRNA) are small non-coding RNAs involved in post-transcriptional gene regulation that have crucial roles in several types of tumors, including papillary thyroid carcinoma (PTC). miR-146b-5p is overexpressed in PTCs and is regarded as a relevant diagnostic marker for this type of cancer. A computational search revealed that miR-146b-5p putatively binds to the 3' untranslated region (UTR) of SMAD4, an important member of the transforming growth factor ß (TGF-ß) signaling pathway. The TGF-ß pathway is a negative regulator of thyroid follicular cell growth, and the mechanism by which thyroid cancer cells evade its inhibitory signal remains unclear. We questioned whether the modulation of the TGF-ß pathway by miR-146b-5p can contribute to thyroid tumorigenesis. Luciferase reporter assay confirmed the direct binding of miR-146b-5p on the SMAD4 3'UTR. Specific inhibition of miR-146b-5p with a locked nucleic acid-modified anti-miR-146b oligonucleotide significantly increased SMAD4 levels in the human papillary carcinoma cell lines, TPC-1 and BCPAP. Moreover, suppression of miR-146b-5p increased the cellular response to the TGF-ß anti-proliferative signal, significantly decreasing the proliferation rate. The overexpression of miR-146b-5p in normal rat follicular PCCL3 cells decreased SMAD4 levels and disrupted TGF-ß signal transduction. MiR-146b-5p overexpression in PCCL3 cells also significantly increased cell proliferation in the absence of thyroid-stimulating hormone and conferred resistance to TGF-ß-mediated cell-cycle arrest. Additionally, the activation of thyroid most common oncogenes RET/PTC3 and BRAF in PCCL3 cells upregulated miR-146b-5p expression. Our results confirm the oncogenic role of miR-146b-5p in thyroid follicular cells and contribute to knowledge regarding the modulation of TGF-ß signal transduction by miRNAs in PTCs.
Assuntos
Carcinoma Papilar/genética , MicroRNAs/fisiologia , Oncogenes , Proteína Smad4/metabolismo , Neoplasias da Glândula Tireoide/genética , Fator de Crescimento Transformador beta/metabolismo , Regiões 3' não Traduzidas , Animais , Linhagem Celular Tumoral , Transformação Celular Neoplásica , Regulação Neoplásica da Expressão Gênica , Humanos , MicroRNAs/antagonistas & inibidores , Ratos , Transdução de Sinais , Proteína Smad4/genética , Glândula Tireoide/citologiaRESUMO
GABA(A) and GABA(B) receptors are present in the lateral parabrachial nucleus (LPBN), a pontine area involved with inhibitory mechanisms related to the control of sodium appetite. Activation of GABA(A) receptors in the LPBN induces strong ingestion of 0.3 M sodium chloride (NaCl) in normonatremic and euhydrated rats. In the present study, we investigated the effects of the GABA(B) receptor agonist baclofen, injected alone or combined with GABA(A) or GABA(B) receptor antagonists into the LPBN on 0.3 M NaCl, water, 0.06 M sucrose and food intake in normonatremic and euhydrated rats. Male Holtzman rats with stainless steel cannulas implanted bilaterally in the LPBN were used. In normonatremic and euhydrated rats, bilateral injections of baclofen (0.5 nmol/0.2 µl) into the LPBN induced 0.3 M NaCl (24.0±3.1 vs. saline: 2.0±0.8 ml/240 min) and water intake (10.6±1.4 vs. saline: 3.5±0.7 ml/240 min) in a two-bottle test. Injections of GABA(B) receptor antagonists CGP 35348 (50 nmol/0.2 µl) or 2-hydroxysaclofen (5 nmol/0.2 µl) or GABA(A) receptor antagonist bicuculline (1.6 nmol/0.2 µl) into the LPBN reduced 0.3 M NaCl (14.1±4.7 ml/240 min; 9.97±2.5 ml/210 min; 8.8±5.9 ml/240 min, respectively) and water intake induced by baclofen injected into the LPBN. Baclofen (0.5 nmol/0.2 µl) injected into the LPBN also induced 0.06 M sucrose intake (21.8±5.9 vs. saline: 5.0±2.6 ml/180 min). Urinary volume and sodium excretion had a tendency to decrease after baclofen injection into the LPBN, whereas arterial pressure and food intake were not affected. The results show that baclofen injected into the LPBN, in normonatremic and euhydrated rats, produces a natriorexigenic effect dependent on GABA(A) and GABA(B) receptor activation. The natriorexigenic effect is not secondary to alterations in blood pressure or sodium urinary excretion. In addition, baclofen injected into the LPBN also induces 0.06 M sucrose intake.
Assuntos
Baclofeno/farmacologia , Comportamento de Ingestão de Líquido/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Agonistas dos Receptores de GABA-B/farmacologia , Ponte/efeitos dos fármacos , Solução Salina Hipertônica/metabolismo , Sacarose/metabolismo , Análise de Variância , Animais , Pressão Sanguínea/efeitos dos fármacos , Ingestão de Líquidos/efeitos dos fármacos , Esquema de Medicação , Interações Medicamentosas , Antagonistas GABAérgicos/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Masculino , Natriurese/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley , Fatores de Tempo , Micção/efeitos dos fármacosRESUMO
Alpha-thalassemia is the most common inherited disorder of hemoglobin synthesis. Genomic deletions involving the alpha-globin gene cluster on chromosome 16p13.3 are the most frequent molecular causes of the disease. Although common deletions can be detected by a single multiplex gap-PCR, the rare and novel deletions depend on more laborious techniques for their identification. The multiplex ligation-dependent probe amplification (MLPA) technique has recently been used for this purpose and was successfully used in the present study to detect the molecular alterations responsible for the alpha-thalassemic phenotypes in 8 unrelated individuals (3 males and 5 females; age, 4 months to 30 years) in whom the molecular basis of the disease could not be determined by conventional methods. A total of 44 probe pairs were used for MLPA, covering approximately 800 kb from the telomere to the MSLN gene in the 16p13.3 region. Eight deletions were detected. Four of these varied in size from 240 to 720 kb and affected a large region including the entire alpha-globin gene cluster and its upstream regulatory element (alpha-MRE), while the other four varied in size from 0.4 to 100 kb and were limited to a region containing this element. This study is the first in Brazil to use the MLPA method to determine the molecular basis of alpha-thalassemia. The variety of rearrangements identified highlights the need to investigate all cases presenting microcytosis and hypochromia, but without iron deficiency or elevated hemoglobin A2 levels and suggests that these rearrangements may be more frequent in our population than previously estimated.
Assuntos
Adolescente , Adulto , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Adulto Jovem , Sondas de DNA/genética , Reação em Cadeia da Polimerase Multiplex , Mutação/genética , alfa-Globinas/genética , Talassemia alfa/genética , Brasil , Genótipo , Linhagem , Fenótipo , Sensibilidade e Especificidade , Talassemia alfa/diagnósticoRESUMO
Alpha-thalassemia is the most common inherited disorder of hemoglobin synthesis. Genomic deletions involving the alpha-globin gene cluster on chromosome 16p13.3 are the most frequent molecular causes of the disease. Although common deletions can be detected by a single multiplex gap-PCR, the rare and novel deletions depend on more laborious techniques for their identification. The multiplex ligation-dependent probe amplification (MLPA) technique has recently been used for this purpose and was successfully used in the present study to detect the molecular alterations responsible for the alpha-thalassemic phenotypes in 8 unrelated individuals (3 males and 5 females; age, 4 months to 30 years) in whom the molecular basis of the disease could not be determined by conventional methods. A total of 44 probe pairs were used for MLPA, covering approximately 800 kb from the telomere to the MSLN gene in the 16p13.3 region. Eight deletions were detected. Four of these varied in size from 240 to 720 kb and affected a large region including the entire alpha-globin gene cluster and its upstream regulatory element (alpha-MRE), while the other four varied in size from 0.4 to 100 kb and were limited to a region containing this element. This study is the first in Brazil to use the MLPA method to determine the molecular basis of alpha-thalassemia. The variety of rearrangements identified highlights the need to investigate all cases presenting microcytosis and hypochromia, but without iron deficiency or elevated hemoglobin A2 levels and suggests that these rearrangements may be more frequent in our population than previously estimated.
Assuntos
Sondas de DNA/genética , Reação em Cadeia da Polimerase Multiplex , Mutação/genética , alfa-Globinas/genética , Talassemia alfa/genética , Adolescente , Adulto , Brasil , Pré-Escolar , Feminino , Genótipo , Humanos , Lactente , Masculino , Mesotelina , Linhagem , Fenótipo , Sensibilidade e Especificidade , Adulto Jovem , Talassemia alfa/diagnósticoRESUMO
BACKGROUND AND OBJECTIVES: The human neutrophil antigen-2 (HNA-2) is expressed on a subpopulation of neutrophils as most subjects present a negative plus a positive HNA-2 population of neutrophils. The number of neutrophils expressing HNA-2 is variable and may increase in pregnancy, infections, myeloproliferative disorders and after G-CSF. This study investigated the presence of polymorphisms in the gene encoding HNA-2 (CD177) in individuals presenting different patterns of antigen expression and determined the association of single nucleotide polymorphisms (SNPs) with the heterogeneous HNA-2 expression. MATERIALS AND METHODS: Flow cytometry was employed to analyse the HNA-2 expression on neutrophils from 135 healthy subjects using two monoclonal antibodies (TAG4, 7D8). Sequencing reactions were performed on subjects whose antigen expression was low (< or = 50%), high (> or = 80%) or atypical (a nonreactive population plus two distinct positive cell populations). RESULTS: Five SNPs were detected, two of them (A793C, G1084A) were related to a low expression of HNA-2 (P = 0.031 and P = 0.004). Atypical antigen expression was observed in 5.9% (8/135) of the individuals, three nonpregnant women and five men. In these cases, the cDNA sequences revealed three SNPs (A134T, G156A and G1333A) strongly related to this atypical HNA-2 expression (P = 0.004, P = 0.006 and P < 0.0001, respectively). CONCLUSIONS: Our data show that polymorphisms in the CD177 are associated with variations in the HNA-2 expression and may be the cause of atypical expressions.
Assuntos
Isoantígenos/genética , Glicoproteínas de Membrana/genética , Neutrófilos/imunologia , Receptores de Superfície Celular/genética , Adulto , Feminino , Citometria de Fluxo , Proteínas Ligadas por GPI , Humanos , Isoantígenos/biossíntese , Isoantígenos/sangue , Isoantígenos/imunologia , Masculino , Glicoproteínas de Membrana/biossíntese , Glicoproteínas de Membrana/sangue , Glicoproteínas de Membrana/imunologia , Pessoa de Meia-Idade , Neutrófilos/metabolismo , Polimorfismo de Nucleotídeo Único , Receptores de Superfície Celular/biossíntese , Receptores de Superfície Celular/sangue , Receptores de Superfície Celular/imunologia , Adulto JovemRESUMO
INTRODUCTION: Renal length estimation by ultrasound is an important parameter in clinical evaluation of kidney disease and healthy donors. Changes in renal volume may be a sign of kidney disease. Correct interpretation of renal length requires the knowledge of normal limits, these have not been described for Latin American population. OBJECTIVE: To describe normal renal length (RL) by ultrasonography in a group of Mexican adults. METHODS: Ultrasound measure of RL in 153 healthy Mexican adults stratified by age. Describe the association of RL to several anthropometric variables. RESULTS: A total of 77 males and 76 females were scanner. The average age for the group was 44.12 +/- 15.44 years. The mean weight, body mass index (BMI) and height were 68.87 +/- 11.69 Kg, 26.77 +/- 3.82 kg/m2 and 160 +/- 8.62 cm respectively. Dividing the population by gender, showed a height of 166 +/- 6.15 cm for males and 154.7 +/- 5.97 cm for females (p =0.000). Left renal length (LRL) in the whole group was 105.8 +/- 7.56 mm and right renal length (RRL) was 104.3 +/- 6.45 mm (p = 0.000.) The LRL for males was 107.16 +/- 6.97 mm and for females was 104.6 +/- 7.96 mm. The average RRL for males was 105.74 +/- 5.74 mm and for females 102.99 +/- 6.85 mm (p = 0.008.) We noted that RL decreased with age and the rate of decline accelerates alter 60 years of age. Both lengths correlated significantly and positively with weight, BMI and height. CONCLUSIONS: The RL was significantly larger in males than in females in both kidneys (p = 0.036) in this Mexican population. Renal length declines after 60 years of age and specially after 70 years.
Assuntos
Rim/anatomia & histologia , Rim/diagnóstico por imagem , Adulto , Idoso , Feminino , Humanos , Masculino , México , Pessoa de Meia-Idade , Tamanho do Órgão , Estudos Prospectivos , Valores de Referência , Ultrassonografia , Adulto JovemAssuntos
Fatores de Transcrição SOXE/genética , Talassemia alfa/genética , Adulto , Brasil , Criança , Família , Feminino , Deleção de Genes , Globinas/genética , Humanos , Masculino , Pessoa de Meia-Idade , Síndrome , Adulto JovemRESUMO
The inhibitory effect of supraphysiological iodide concentrations on thyroid hormone synthesis (Wolff-Chaikoff effect) and on thyrocyte proliferation is largely known as iodine autoregulation. However, the molecular mechanisms by which iodide modulates thyroid function remain unclear. In this paper, we analyze the transcriptome profile of the rat follicular cell lineage PCCl3 under untreated and treated conditions with 10(-3) M sodium iodide (NaI). Serial analysis of gene expression (SAGE) revealed 84 transcripts differentially expressed in response to iodide (p
Assuntos
Perfilação da Expressão Gênica , Iodetos/farmacologia , Glândula Tireoide/efeitos dos fármacos , Animais , Sequência de Bases , Linhagem Celular , RNA Mensageiro/genética , Ratos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Glândula Tireoide/citologia , Glândula Tireoide/metabolismoRESUMO
OBJECTIVE: To compare the pharmacokinetics and report on the clinical effects of methotrexate (MTX) in patients with juvenile idiopathic arthritis (JIA), receiving long-term MTX or MTX plus chloroquine (CQ). METHODS: The pharmacokinetics of MTX, clinical characteristics (morning stiffness, joint tenderness and number of swollen joints) and biochemical markers (A-amyloid substance, C-reactive protein, erythrocyte sedimentation rate, fibrinogen and alpha-glycoprotein acid, alanine transaminase and aspartate transaminase) of the JIA patients were determined. Eight patients were treated with MTX (0.15 mg/kg) and another eight with MTX (0.15 mg/kg) plus CQ (4 mg/kg) for at least 6 months. RESULTS: All patients had polyarticular involvement and the clinical characteristics and biochemical markers were similar for the two groups. The pharmacokinetics of MTX were also similar with the Cmax and AUC values being 455.00 +/- 101.00 nm and 1469.92 +/- 299.77 nm/h for MTX group and 425.00 +/- 169.60 nm and 1560.73 +/- 615.49 nm/h for MTX plus CQ group, respectively. The respective creatinine clearance was 117.95 +/- 12.58 for MTX group and 99.17 +/- 22.65 mL/min for MTX plus CQ. CONCLUSION: The pharmacokinetics of MTX in JIA patients treated chronically with MTX are similar, with or without CQ co-treatment.
Assuntos
Antirreumáticos/farmacocinética , Cloroquina/administração & dosagem , Metotrexato/farmacocinética , Adolescente , Adulto , Área Sob a Curva , Artrite Juvenil , Criança , Quimioterapia Combinada , Feminino , Humanos , Masculino , Metotrexato/administração & dosagemRESUMO
The RAS protooncogene has an important, although not yet established role in thyroid neoplasia. In this study, we evaluated the H-RAS mRNA and protein levels in human samples of nontoxic and toxic multinodular goiter samples, according to serum TSH levels. The mean of H-RAS mRNA levels in nodules of nontoxic nodular goiter were significantly increased compared to nonnodular tissue (1.49+/-1.21 vs. 0.94+/-0.81 AU, P=0.016). Nine of the 18 specimens (50%) of nontoxic multinodular goiter exhibited increased levels of H-RAS mRNA. The increased H-RAS mRNA levels were paralleled by inRAcreased H-Ras protein levels in about 90% of the cases. Interestingly, no differences were observed in H-RAS expression between nodules and adjacent nonnodular tissue in toxic nodular goiters (0.58+/-0.27 vs. 0.58+/-0.20 AU, P=0.88). None of the 10 samples from toxic multinodular goiters exhibited overexpression of H-RAS. The H-RAS expression was positively correlated with thyroglobulin expression (r2=0.51; P=0.04). In conclusion, we demonstrated increased levels of H-RAS mRNA and protein in samples of nontoxic multinodular goiter, indicating that it might be involved in goiter pathogenesis. In contrast, H-RAS overexpression was not detected in any of the samples of toxic multinodular goiter, suggesting different mechanisms for cell proliferation in nodular goiter according to thyroid status.
Assuntos
Expressão Gênica , Genes ras , Bócio Nodular/genética , Proteína Oncogênica p21(ras)/genética , Tireotoxicose/genética , Adulto , Idoso , Proliferação de Células , Análise Mutacional de DNA , Feminino , Bócio Nodular/metabolismo , Bócio Nodular/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Proteína Oncogênica p21(ras)/metabolismo , RNA Mensageiro/metabolismo , Estudos Retrospectivos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Tireoglobulina/metabolismo , Tireotoxicose/metabolismo , Tireotoxicose/patologia , Tireotropina/metabolismoRESUMO
Hemoglobin (Hb) Indianapolis [beta112 (G14) Cys-->Arg] is a rare and slightly unstable beta-globin variant. All carriers described to date were clinically normal with only mild reticulocytosis. We report here a case of a Brazilian patient in whom hemolytic anemia and acute renal failure were probably caused by the presence of this variant.
Assuntos
Anemia Hemolítica/metabolismo , Anemia Hemolítica/patologia , Cisteína/genética , Hemoglobinas Anormais/genética , Hemoglobinas Anormais/metabolismo , Rim/metabolismo , Rim/patologia , Adulto , Anemia Hemolítica/genética , Arginina/genética , Arginina/metabolismo , Sequência de Bases , Brasil , Criança , Pré-Escolar , Cisteína/metabolismo , Feminino , Humanos , Masculino , Dados de Sequência MolecularAssuntos
Anemia Hemolítica Congênita/complicações , Anemia Hemolítica Congênita/genética , Corpos de Heinz/patologia , Hemoglobinas Anormais/análise , Hemoglobinas Anormais/genética , Anemia Hemolítica Congênita/patologia , Brasil , Pré-Escolar , Feminino , Testes Genéticos , Globinas/genética , Humanos , Mutação Puntual , Reação em Cadeia da Polimerase/métodos , Sensibilidade e Especificidade , Análise de Sequência de DNARESUMO
We report here a new frameshift mutation in exon 3 of the beta-globin gene, a single nucleotide deletion (-C) in between codons 140/141 (GCC/CTG-->GCC/TG), found in an 8-year-old Argentinean girl with clinical picture of thalassemia intermedia. It leads to a beta-chain that is elongated to 156 amino acids [(141)Trp-Pro-Thr-Ser-Ile-Thr-Lys-Leu-Ala-Phe-Leu-Leu-Ser-Asn-Phe-(156)Tyr-COOH]. The resulting hemoglobin, which we named Hb Florida, was not detected in peripheral blood; however, erythroid hyperplasia and dyserythropoiesis with large inclusion bodies on methyl violet staining were observed in bone marrow, suggesting that this is a hyperunstable variant producing a dominant beta-thalassemia phenotype, since the other beta-allele was completely normal.
Assuntos
Globinas/genética , Hemoglobinas Anormais/genética , Talassemia beta/genética , Sequência de Bases , Criança , Feminino , Mutação da Fase de Leitura , Humanos , Deleção de Sequência , Talassemia beta/sangueRESUMO
The present study evaluates the effects of methotrexate (MTX) and chloroquine (CQ), and of combined MTX + CQ treatment, on the inflammatory response and on plasma and liver phosphatase and transaminase activities, employing an adjuvant-induced arthritis model in rats. Arthritis was induced by the intradermal injection of a suspension of Mycobacterium tuberculosis in mineral oil into the plantar surface of the hind paws. Development of the inflammatory response was assessed over a 21-day period. Animal groups received either: (i) MTX, administered i.p., weekly, in 0.15, 1.5, 3, 6 or 12 mg/kg doses; (ii) CQ, given intragastrically, in daily 25 or 50 mg/kg doses; or (iii) MTX + CQ, administered in two combinations (MTX1.5 mg/kg + CQ50 mg/kg, or MTX6 mg/kg + CQ50 mg/kg). At the end of the experimental period, the animals were anesthetized and killed, blood and liver samples were collected and prepared for measurement of acid and alkaline phosphatase (AP, ALP), and aspartate (AST) and alanine aminotransferase (ALT) activities. MTX at 6 and 12 mg/kg reduced the inflammatory response while CQ had no effect. MTX6 mg/kg + CQ50 mg/kg reduced the inflammatory response similar to MTX12 mg/kg, without affecting the bone marrow. Plasma AP and liver ALP activities were very elevated in the arthritic rats. While MTX treatment partially reduced both plasma AP and liver ALP activities at all doses used in the arthritic rats, CQ treatment reduced plasma AP, but increased liver AP activity. MTX + CQ treatment decreased plasma AP and liver ALP activities in the arthritic rats to control values. Plasma and liver AST activities were unaltered in the arthritic rats, and were unaffected by treatment. However, plasma and liver ALT activities were significantly reduced in the arthritic rats. While MTX or CQ treatment did not alter plasma transaminase activity in the arthritic rats, after MTX + CQ treatment, plasma ALT activity returned to normal values. In conclusion, the present data suggest that MTX + CQ treatment provides more effective anti-inflammatory protection against adjuvant-induced arthritis than does MTX alone, reverting the alterations in enzyme activities induced by this inflammatory disease in rats.
Assuntos
Artrite Experimental/tratamento farmacológico , Cloroquina/administração & dosagem , Metotrexato/administração & dosagem , Fosfatase Ácida/metabolismo , Alanina Transaminase/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Artrite Experimental/enzimologia , Aspartato Aminotransferases/metabolismo , Peso Corporal/efeitos dos fármacos , Quimioterapia Combinada , Fígado/enzimologia , Masculino , RatosRESUMO
Leptospira species colonize a significant proportion of rodent populations worldwide and produce life-threatening infections in accidental hosts, including humans. Complete genome sequencing of Leptospira interrogans serovar Copenhageni and comparative analysis with the available Leptospira interrogans serovar Lai genome reveal that despite overall genetic similarity there are significant structural differences, including a large chromosomal inversion and extensive variation in the number and distribution of insertion sequence elements. Genome sequence analysis elucidates many of the novel aspects of leptospiral physiology relating to energy metabolism, oxygen tolerance, two-component signal transduction systems, and mechanisms of pathogenesis. A broad array of transcriptional regulation proteins and two new families of afimbrial adhesins which contribute to host tissue colonization in the early steps of infection were identified. Differences in genes involved in the biosynthesis of lipopolysaccharide O side chains between the Copenhageni and Lai serovars were identified, offering an important starting point for the elucidation of the organism's complex polysaccharide surface antigens. Differences in adhesins and in lipopolysaccharide might be associated with the adaptation of serovars Copenhageni and Lai to different animal hosts. Hundreds of genes encoding surface-exposed lipoproteins and transmembrane outer membrane proteins were identified as candidates for development of vaccines for the prevention of leptospirosis.