Spirooxadiazoline-oxindoles derived from imatinib show antimyeloproliferative potential in K562 cells.

Imatinib mesylate was the first representative BCR-ABL1 tyrosine kinase inhibitor (TKI) class for the treatment of chronic myeloid leukemia. Despite the revolution promoted by TKIs in the treatment of this pathology, a resistance mechanism occurs against all BCR-ABL1 inhibitors, necessitating a constant search for new therapeutic options. To develop new antimyeloproliferative substances, we applied a medicinal chemistry tool known as molecular hybridization to design 25 new substances. These compounds were synthesized and biologically evaluated against K562 cells, which express BCR-ABL1, a constitutively active tyrosine kinase enzyme, as well as in WSS-1 cells (healthy cells). The new compounds are conjugated hybrids that contain phenylamino-pyrimidine-pyridine (PAPP) and an isatin backbone, which are the main pharmacophoric fragments of imatinib and sunitinib, respectively. A spiro-oxindole nucleus was used as a linker because it occurs in many compounds with antimyeloproliferative activity. Compounds 2a, 2b, 3c, 4c, and 4e showed promise, as they inhibited cell viability by between 45% and 61% at a concentration of 10 µM. The CC50 of the most active substances was determined to be within 0.8-9.8 µM.

Neurological impairment caused by Schistosoma mansoni systemic infection exhibits early features of idiopathic neurodegenerative disease.

Schistosomiasis, a neglected tropical disease caused by trematodes of the Schistosoma genus, affects over 250 million people around the world. This disease has been associated with learning and memory deficits in children, whereas reduced attention levels, impaired work capacity, and cognitive deficits have been observed in adults. Strongly correlated with poverty and lack of basic sanitary conditions, this chronic endemic infection is common in Africa, South America, and parts of Asia and contributes to inhibition of social development and low quality of life in affected areas. Nonetheless, studies on the mechanisms involved in the neurological impairment caused by schistosomiasis are scarce. Here, we used a murine model of infection with Schistosoma mansoni in which parasites do not invade the central nervous system to evaluate the consequences of systemic infection on neurologic function. We observed that systemic infection with S. mansoni led to astrocyte and microglia activation, expression of oxidative stress-induced transcription factor Nrf2, oxidative damage, Tau phosphorylation, and amyloid-ß peptide accumulation in the prefrontal cortex of infected animals. We also found impairment in spatial learning and memory as evaluated by the Morris water maze task. Administration of anthelmintic (praziquantel) and antioxidant (N-acetylcysteine plus deferoxamine) treatments was effective in inhibiting most of these phenotypes, and the combination of both treatments had a synergistic effect to prevent such changes. These data demonstrate new perspectives toward the understanding of the pathology and possible therapeutic approaches to counteract long-term effects of systemic schistosomiasis on brain function.

Programmable bio-nanochip-based cytologic testing of oral potentially malignant disorders in Fanconi anemia.

Fanconi anemia (FA) is caused by mutations of DNA repair genes. The risk of oral squamous cell carcinoma (OSCC) among FA patients is 800-folds higher than in the general population. Early detection of OSCC, preferably at it precursor stage, is critical in FA patients to improve their survival. In an ongoing clinical trial, we are evaluating the effectiveness of the programmable bio-nanochip (p-BNC)-based oral cytology test in diagnosing oral potentially malignant disorders (OPMD) in non-FA patients. We used this test to compare cytomorphometric and molecular biomarkers in OSCC cell lines derived from FA and non-FA patients to brush biopsy samples of a FA patient with OPMD and normal mucosa of healthy volunteers. Our data showed that expression patterns of molecular biomarkers were not notably different between sporadic and FA-OSCC cell lines. The p-BNC assay revealed significant differences in cytometric parameters and biomarker MCM2 expression between cytobrush samples of the FA patient and cytobrush samples of normal oral mucosa obtained from healthy volunteers. Microscopic examination of the FA patient's OPMD confirmed the presence of dysplasia. Our pilot data suggests that the p-BNC brush biopsy test recognized dysplastic oral epithelial cells in a brush biopsy sample of a FA patient.

Utility of salivary biomarkers for demonstrating acute myocardial infarction.

The comparative utility of serum and saliva as diagnostic fluids for identifying biomarkers of acute myocardial infarction (AMI) was investigated. The goal was to determine if salivary biomarkers could facilitate a screening diagnosis of AMI, especially in cases of non-ST elevation MI (NSTEMI), since these cases are not readily identified by electrocardiogram (ECG). Serum and unstimulated whole saliva (UWS) collected from 92 AMI patients within 48 hours of chest pain onset and 105 asymptomatic healthy control individuals were assayed for 13 proteins relevant to cardiovascular disease, by Beadlyte technology (Luminex(®)) and enzyme immunoassays. Data were analyzed with concentration cut-points, ECG findings, logistic regression (LR) (adjusted for matching for age, gender, race, smoking, number of teeth, and oral health status), and classification and regression tree (CART) analysis. A sensitivity analysis was conducted by repetition of the CART analysis in 58 cases and 58 controls, each matched by age and gender. Serum biomarkers demonstrated AMI sensitivity and specificity superior to that of saliva, as determined by LR and CART. The predominant discriminators in serum by LR were troponin I (TnI), B-type natriuretic peptide (BNP), and creatine kinase-MB (CK-MB), and TnI and BNP by CART. In saliva, LR identified C-reactive protein (CRP) as the biomarker most predictive of AMI. A combination of smoking tobacco, UWS CRP, CK-MB, sCD40 ligand, gender, and number of teeth identified AMI in the CART decision trees. When ECG findings, salivary biomarkers, and confounders were included, AMI was predicted with 80.0% sensitivity and 100% specificity. These analyses support the potential utility of salivary biomarker measurements used with ECG for the identification of AMI. Thus, saliva-based tests may provide additional diagnostic screening information in the clinical course for patients suspected of having an AMI.

Synthesis, cytotoxicity and mechanistic evaluation of 4-oxoquinoline-3-carboxamide derivatives: finding new potential anticancer drugs.

As part of a continuing search for new potential anticancer candidates, we describe the synthesis, cytotoxicity and mechanistic evaluation of a series of 4-oxoquinoline-3-carboxamide derivatives as novel anticancer agents. The inhibitory activity of compounds 10-18 was determined against three cancer cell lines using the MTT colorimetric assay. The screening revealed that derivatives 16b and 17b exhibited significant cytotoxic activity against the gastric cancer cell line but was not active against a normal cell line, in contrast to doxorubicin, a standard chemotherapeutic drug in clinical use. Interestingly, no hemolytical activity was observed when the toxicity of 16b and 17b was tested against blood cells. The in silico and in vitro mechanistic evaluation indicated the potential of 16b as a lead for the development of novel anticancer agents against gastric cancer cells.

Isolation and expression of a hypotensive and anti-platelet acidic phospholipase A2 from Bothrops moojeni snake venom.

Phospholipases A(2) are important components of snake venoms, the basic isoforms have been more extensively studied than the acidic groups, maybe due to their higher toxicity. Trying to better understand the role of the acidic isoforms on the envenomation process, an acidic phospholipase A(2) was purified from Bothrops moojeni snake venom through two chromatographic steps (BmooPLA(2)). The enzyme showed a relative molecular mass of 13,601Da, pI 5.2, high phospholipase activity, bactericidal effect, moderate cytotoxic activity and was able to inhibit platelet aggregation. Moreover, BmooPLA(2) induced moderate in vivo edema and hypotensive effect. The 414bp cDNA encoding the BmooPLA(2) was cloned and expressed in Escherichia coli. The recombinant BmooPLA(2) showed phospholipase and inhibitory activities on platelet aggregation similar to those of the native protein. A comparative study between BmooPLA(2), the acidic (BthA-I) and basic (BthTX-II) PLA(2) from B. jararacussu venom showed that the effects of BmooPLA(2) and BthA-I-PLA(2) are similar. BmooPLA(2) is the first isolated and characterized non-myotoxic PLA(2) from B. moojeni snake venom. The recombinant PLA(2) can substitute the native toxin in studies aiming its biotechnological application in order to help the preservation of this endangered species. These data along with the preliminary structural studies here reported will provide a better understanding of this important class of proteins.

Exploring the DNA binding/cleavage, cellular accumulation and topoisomerase inhibition of 2-hydroxy-3-(aminomethyl)-1,4-naphthoquinone Mannich bases and their platinum(II) complexes.

Several chlorido and amino Pt(2+) complexes of 2-hydroxy-3-(aminomethyl)-1,4-naphthoquinone Mannich bases HL exhibiting moderate to high cytotoxicity against cancer cell lines were studied in order to investigate their modes of DNA binding, in vitro DNA strand breaks, mechanism of topoisomerase (Topo I) inhibition and cellular accumulation. DNA model base studies have shown that complex 1a [Pt(HL1)Cl(2)] was capable of binding covalently to 9-ethylguanine (9-EtG) and 5'-GMP. (1)H NMR and mass spectrometry studies have shown that both chlorides were substituted by 9-EtG ligands, whereas 5'-GMP was able to replace only one chlorido ligand, due to steric hindrance. The chlorido Pt(2+) complexes [Pt(HL)Cl(2)] highly accumulate in prostate (PC-3) and melanoma (MDA-MB-435) cell lines, being able to induce DNA strand breaks in vitro and inhibit Topo I by a catalytic mode. On the other hand, the free 2-hydroxy-3-(aminomethyl)-1,4-naphthoquinones HL and the amino Pt(2+) complexes [Pt(L(-))(NH(3))(2)]NO(3) neither cause DNA strand breakage nor exhibit strong DNA interaction, nevertheless the latter were also found to be catalytic inhibitors of Topo I at 100µM. Thus, coordination of the Mannich bases HL to the "PtCl(2)" fragment substantially affects the chemical and biophysical properties of the pro-ligands, leading to an improvement of their DNA binding properties and generating compounds that cleave DNA and catalytically inhibit Topo I. Finally, the high cytotoxicity exhibited by the free (uncomplexed) 2-hydroxy-3-(aminomethyl)-1,4-naphthoquinones might be associated with their decomposition in solution, which is not observed for the Pt(2+) complexes.

Sequence analysis of NAT2 gene in Brazilians: identification of undescribed single nucleotide polymorphisms and molecular modeling of the N-acetyltransferase 2 protein structure.

N-Acetyltransferase 2 (NAT2) metabolizes a variety of xenobiotics that includes many drugs, chemicals and carcinogens. This enzyme is genetically variable in human populations and polymorphisms in the NAT2 gene have been associated with drug toxicity and efficacy as well as cancer susceptibility. Here, we have focused on the identification of NAT2 variants in Brazilian individuals from two different regions, Rio de Janeiro and Goiás, by direct sequencing, and on the characterization of new haplotypes after cloning and re-sequencing. Upon analysis of DNA samples from 404 individuals, six new SNPs (c.29T>C, c.152G>T, c.203G>A, c.228C>T, c.458C>T and c.600A>G) and seven new NAT2 alleles were identified with different frequencies in Rio de Janeiro and Goiás. All new SNPs were found as singletons (observed only once in 808 genes) and were confirmed by three independent technical replicates. Molecular modeling and structural analysis suggested that p.Gly51Val variant may have an important effect on substrate recognition by NAT2. We also observed that amino acid change p.Cys68Tyr would affect acetylating activity due to the resulting geometric restrictions and incompatibility of the functional group in the Tyr side chain with the admitted chemical mechanism for catalysis by NATs. Moreover, other variants, such like p.Thr153Ile, p.Thr193Met, p.Pro228Leu and p.Val280Met, may lead to the presence of hydrophobic residues on NAT2 surface involved in protein aggregation and/or targeted degradation. Finally, the new alleles NAT2*6H and NAT2*5N, which showed the highest frequency in the Brazilian populations considered in this study, may code for a slow activity. Functional studies are needed to clarify the mechanisms by which new SNPs interfere with acetylation.

Ressecção Parcial de Palato (RPP) para tratamento de roncopatia pela Técnica de Quesada e Perelló: resultados / Partial Resection of the Palate in the treatment of snoring by Quesada & Perelló technique: results

Roncopatia é uma entidade relativamente comum, presente em 38 por cento das mulheres e 40 por cento dos homens, com importantes implicações sociais. Várias técnicas são descritas na literatura para a correção da hipertrofia do palato mole, associadas a outros procedimentos, com o propósito de remissão dos sintomas. OBJETIVO: Para estudar os resultados da técnica proposta por Quesada e Perelló, denominada Ressecção Parcial do Palato (RPP), avaliamos a remissão do ronco, as complicações e o conforto pós-operatório do paciente. FORMA DE ESTUDO: Clínico retrospectivo. MATERIAL E MÉTODO: 28 pacientes foram arrolados no estudo, de abril de 1994 a agosto de 2000, mas apenas 23 preencheram os critérios de inclusão, com queixas de ronco sem alterações compatíveis com apnéia obstrutiva. Todos os pacientes apresentavam classificação de Fujita tipo I ou II e foram avaliados com polissonografia, tomografia computadorizada e exame otorrinolaringológico completo. RESULTADOS: Após 6 meses, a remissão dos sintomas foi total em 12 casos (42 por cento), parcial em 9 (32 por cento) e inalterado em 2 (7 por cento); 5 pacientes não completaram o acompanhamento de seis meses. CONCLUSÃO: A técnica de Ressecção Parcial do Palato proposta por Quesada et al. e Perelló mostrou-se segura e eficaz no tratamento do ronco.

Phenylisothiocyanate and dansyl chloride precolumn derivatizations for the high-performance liquid chromatography analysis of the antitumoral agent ES-285 in dog plasma.

Chromophor and fluorophor addition reactions involving phenylisothiocyanate (PITC) and dansyl chloride (DC) were optimized to adapt two high-performance liquid chromatography (HPLC) procedures designed for the accurate determination of the novel antitumoral agent ES-285 in Beagle dog plasma. ES-285 was reacted with PITC at 60 degrees C for 15 min in the presence of triethylamine. The dansyl derivative was obtained by reaction of ES-285 with dansyl chloride in a basic medium at 80 degrees C for 20 min. Both reactions also worked for ES-299, a compound structurally related to ES-285 which was used as internal standard. The treatment of ES-285 and ES-299 spiked plasma samples with a basic phosphate buffer and MeOH permitted the extraction of the drug from the matrix. The purification of the analytes was carried out by solid-phase extraction followed by precolumn derivatization with PITC and DC. The phenylisothiocyanate adducts were analyzed by isocratic HPLC with UV detection at 254 nm. The ES-285 and ES-299 derivatives were eluted from a C(18) column at approximately 6.9 and approximately 8.1 min, respectively. The eluent ACN-water (95:5, v/v) was delivered to the column at a flow-rate of 1 ml/min and the analysis was completed in 15 min. The dansyl derivatives were analysed by a two-HPLC column system with fluorescence detection and gradient elution. The column temperature was maintained at 40 degrees C. The analysis lasted 55 min with the elution of ES-285 and ES-299 derivatives at approximately 35.2 and approximately 37.9 min, respectively. The PITC- and DC-based procedures were characterized by limits of quantification of 20 and 15 ng/ml, respectively. Both procedures were validated according to the ICH and FDA guidelines. They were selective for ES-285 and provided accurate, precise and reproducible results. ES-299 was shown to be a suitable internal standard. The HPLC procedure involving derivatization with DC was more sensitive and permitted to process plasma sample volumes as low as 100 microl. On the other hand, the PITC-based procedure characterised by a quite similar LOQ permitted a higher throughput but implied the processing of a 500-microl plasma volume.

Pharmaceutical development of a parenteral lyophilized formulation of the novel antitumor agent aplidine.

Aplidine is a naturally occurring cyclic depsipeptide isolated from the Mediterranean tunicate Aplidium albicans. Aplidine displays promising in vitro and in vivo antitumor activities against various solid human tumor xenografts and is therefore developed now for clinical testing. The aim of this study was to develop a stable parenteral pharmaceutical dosage form for clinical Phase I testing. Aplidine raw material was characterized by using several chromatographic and spectrometric techniques. These experiments showed that aplidine exists as two isomers. A stability-indicating HPLC assay was developed. Solubility testing showed that aplidine exhibits very poor aqueous solubility. Because solubilized aplidine showed substantial degradation under heat and light stress testing conditions, it was decided to develop a lyophilized dosage form. Freeze-drying was carried out with a 500 micrograms/mL solution of aplidine in 40% (v/v) tert-butanol in Water for Injection (WfI) containing 25 mg/mL D-mannitol as a bulking agent. Differential scanning calorimetry was applied to determine the optimal freeze-drying cycle parameters. The prototype, containing 500 micrograms aplidine and 25 mg D-mannitol per vial, was found to be the optimal formulation in terms of solubility, length of lyophilization cycle, and dosage requirements in the forthcoming Phase I clinical studies. Quality control of the freeze-dried formulation demonstrates that the manufacturing process does not affect the integrity of aplidine. The optimal reconstitution solution was found to be 15/15/70% (v/v/v) Cremophor EL/ethanol/WfI (CEW). Both reconstituted product and dilutions of the reconstituted product with normal saline (up to 1:100 v/v) appeared to be stable for at least 24 hours after preparation. Shelf-life data, available thus far, show that the lyophilized formulation is stable for at least 1 year when stored at +2-8 degrees C in the dark.

Alanine prevents the decrease of Na+,K+-ATPase activity in experimental phenylketonuria.

Our objective was to investigate the effect of alanine administration on Na+,K+-ATPase activity in cerebral cortex of rats subjected to chemically-induced phenylketonuria. Wistar rats were treated from the 6th to the 28th day of life with subcutaneous injections of either 2.6 micromol alanine or 5.2 micromol phenylalanine plus 2.6 micromol alpha-methylphenylalanine per g body weight or phenylalanine plus alpha-methylphenylalanine plus alanine in the same doses or equivalent volumes of 0.15 M saline. The animals were killed on the 29th or 60th day of life. Synaptic plasma membrane from cerebral cortex was prepared for Na+,K+-ATPase activity determination. The results showed that alanine injection prevents the decrease of Na+,K+-ATPase activity in animals subjected to experimental phenylketonuria. Therefore, in case the same effects are achieved with ingested alanine, it is possible that alanine supplementation may be an important dietary adjuvant for phenylketonuric patients.

Bioanalysis of aplidine, a new marine antitumoral depsipeptide, in plasma by high-performance liquid chromatography after derivatization with trans-4-hydrazino-2-stilbazole.

A sensitive bio-analytical assay in plasma of the depsipeptide aplidine is reported, based on reversed-phase liquid chromatography and fluorescence detection of the trans-4'-hydrazino-2-stilbazole (4'H2S) derivative of the analyte. At ambient temperature, two conformations of the depsipeptide are observed in solution due to cis-trans isomerism at the proline-pyruvoyl peptide bond. Aplidine is isolated from the matrix by solid-phase extraction on an octadecyl modified silica stationary phase. After evaporation of the acetone eluate, a derivatization with 4'H2S is performed in a water-acetonitrile mixture at pH 4. The reaction mixture is injected directly into the chromatograph and the analyte is quantified by fluorescence detection at 410 and 560 nm for excitation and emission, respectively. The method has been validated in the 2-100 ng/ml-range, 2 ng/ml being the lower limit of quantification. Precision and accuracy both meet the current requirements for a bioanalytical assay. The identity of the 4'H2S reaction products of aplidine have been confirmed by mass spectrometric analysis. Finally, the method has been employed for a pilot pharmacokinetic study of aplidine in mice which demonstrated its usefulness for pharmacological research.

Bioanalysis of thiocoraline, a new marine antitumoral depsipeptide, in plasma by high-performance liquid chromatography and fluorescence detection.

A sensitive bioanalytical assay for thicoraline, an investigational marine anticancer agent, in plasma, based on reversed-phase liquid chromatography and fluorescence detection, is reported. The proteins in the sample are precipitated by the addition of acetonitrile. After centrifugation, the supernatant is injected directly into the chromatograph. The analyte is quantified by fluorescence detection with excitation and emission at 365 and 540 nm, respectively. The method has been validated in the 1-100 ng/ml range, 1 ng/ml being the lower limit of quantification. Precision and accuracy both meet the current requirements for a bio-analytical assay and are <15% at 1 ng/ml and < or =5% in the 5-100 ng/ml range. Plasma samples can be stored for at least 4 months at -80 degrees C. Finally, the usefulness of this method for pharmacological research was shown in a pilot study of the pharmacokinetics of thiocoraline in rats.

Quantitative determination of Ecteinascidin 743 in human plasma by miniaturized high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.

A method was developed for the bio-analysis of Ecteinascidin 743 (ET-743) using miniaturized liquid chromatography (LC) coupled to an electrospray ionization sample inlet (TurbolonSpray) and two quadrupole mass analyzers (LC/ESI-MS/MS). Solid-phase extraction was used as a sample pretreatment procedure. Ecteinascidin 743 is a very potent anticancer compound and is administered in microgram m-2 dosages, which demands special requirements in terms of sensitivity for the analytical method supporting clinical pharmacokinetic studies. Using conventional LC/UV, a lower limit of quantitation (LLQ) of 1 ng ml-1 plasma was reached using a 500 microliters sample volume, but LC/ESI-MS/MS permitted an LLQ of 10 pg ml-1. The latter method was found to be accurate and precise, and provided a broad linear concentration range of 0.010-2.50 ng ml-1.

Analysis of Ecteinascidin 743, a new potent marine-derived anticancer drug, in human plasma by high-performance liquid chromatography in combination with solid-phase extraction.

A reversed-phase high-performance liquid chromatographic method has been developed and validated for the quantification of the novel anticancer drug Ecteinascidin 743 in human plasma. The sample pretreatment of the plasma samples involved a solid-phase extraction (SPE) on cyano columns. Propyl-p-hydroxybenzoate was added after the sample pretreatment to correct for variability in injection volumes. The separation was performed on a Zorbax SB-C18 column (75x4.6 mm I.D., particle size 3.5 microm) with acetonitrile-25 mM phosphate buffer, pH 5.0 (70:30, v/v) as the mobile phase. The flow-rate was 1.0 ml/min and the eluent was monitored at 210 nm. The accuracies and precisions of the assay fall within +/-15% for all quality control samples and within +/-20% for the lower limit of quantitation, which was 1.0 ng/ml using 500 microl of plasma. The overall recovery of the sample pretreatment procedure for Ecteinascidin 743 was 87.0+/-5.9%. The drug was found to be stable in human plasma at -30 degrees C for at least 2 months. At room temperature Ecteinascidin 743 was stable in human plasma for 5 h at most.

[Neuroendocrine carcinoma of the ampullar region with oat-cell histological features and adenocarcinoma]. / Carcinoma neuroendocrino de la región ampular con rasgos histológicos de "oat-cell" y adenocarcinoma.

We report a case of primary duodenal carcinoma showing neuroendocrine and glandular differentiation, in a 65-years-old male. Both components were closely related and transition between them was observed. The neuroendocrine component was composed of an undifferentiated "oat-cell" type, with positive immunostaining for neuroendocrine and epithelial markers. Ultrastructural findings confirmed this double differentiation, with dense cytoplasmatic granules of neurosecretory type. The neuroendocrine component showed greater aggressiveness with lymph node metastasis.

Ameloblastic fibroma: report of two cases.

The ameloblastic fibroma is an odontogenic tumour with an unusual presentation. It is considered to have both epithelial and mesenchymal elements, but it lacks any calcified dental structures. Two new cases are presented. The first of these began as a mandibular tumour whereas the second was discovered by chance. The radiographic finding in each case was a unilocular cystic radiolucency. Treatment consisted of excisional biopsy by enucleation in both patients. Histopathological findings were consistent with ameloblastic fibroma.