Assessment In vitro and In silico of the Activity of Thiadiazines as NorA Efflux Pump Inhibitors.

Antimicrobials fight microorganisms, preventing and treating infectious diseases. However, antimicrobial resistance (AMR) is a growing concern due to the inappropriate and excessive use of these drugs. Several mechanisms can lead to resistance, including efflux pumps such as the NorA pump in Staphylococcus aureus, which reduces the effectiveness of fluoroquinolones. Thiadiazines are heterocyclic compounds whose chemical structure resembles that of cephalosporins. Therefore, these compounds and their derivatives have been studied for their potential in combating increased bacterial resistance. To analyze this hypothesis, direct activity assays, antibiotic action-modifying activity, fluorescence assays to evaluate the retention of ethidium bromide inside bacteria, and molecular docking were carried out. These experiments involved serial dilutions in microplates against Staphylococcus aureus strain 1199B under the influence of six thiadiazine derivatives (IJ10, IJ11, IJ21, IJ22, IJ23, and IJ25). The tests revealed that, despite not showing effective direct activity, some thiadiazine derivatives (IJ11, IJ21, and IJ22) inhibited the function of the bromide pump both in microdilution tests and in fluorescence and docking assays. Particularly, the IJ11 compound stood out for its activity similar to efflux inhibitors, as well as its inhibition of the norfloxacin pump of this bacterium. Among the results of this study, it deserves to be highlighted for anchoring future experiments, as it represents the first investigation of this group of thiadiazine derivatives against the NorA pump.

Sublethal and Transgenerational Effects of Reduced-Risk Insecticides on Macrolophus basicornis (Hemiptera: Miridae).

Reduced-risk insecticides and mirid predators have been used to control Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) in tomato crops. However, even when causing low mortality to the beneficial insects, these products might cause side effects. This study investigated the sublethal and transgenerational effects of buprofezin, cyantraniliprole, and spiromesifen on Macrolophus basicornis (Stal) (Hemiptera: Miridae). After 72 h of exposure of third-instar nymphs and adults to residues on tomato leaves, adult couples were formed and kept in cages with residue-free tomato leaves. The leaves were changed every 48 h and the offspring were assessed in 6 different periods. Body size was assessed by measuring the hind-tibia length of adults (F0) from exposed nymphs and in three different offspring groups. None of the insecticide residues caused a reduction on offspring populations or affected the body size of adults in generation F0. Regardless, buprofezin and spiromesifen reduced the tibia length of adults (F1) from exposed nymphs assayed in the third mating period. Cyantraniliprole did not affect any parameter and could be recommended for control of B. tabaci in association with M. basicornis releases. This study may contribute to future field assays of the compatibility of these insecticides with M. basicornis.

Potentiating-antibiotic activity and absorption, distribution, metabolism, excretion and toxicity properties (ADMET) analysis of synthetic thiadiazines against multi-drug resistant (MDR) strains.

BACKGROUND: Thiadiazines are heterocyclic compounds that contain two nitrogen atoms and one sulfur atom in their structure. These synthetic molecules have several relevant pharmacological activities, such as antifungal, antibacterial, and antiparasitic. OBJECTIVES: The present study aimed to evaluate the possible in vitro and in silico interactions of compounds derived from thiadiazines. METHODS: The compounds were initially synthesized, purified, and confirmed through HPLC methodology. Multi-drug resistant bacterial strains of Staphylococcus aureus 10 and Pseudomonas aeruginosa 24 were used to evaluate the direct and modifying antibiotic activity of thiadiazine derivatives. ADMET assays (absorption, distribution, metabolism, excretion, and toxicity) were conducted, which evaluated the influence of the compounds against thousands of macromolecules considered as bioactive targets. RESULTS: There were modifications in the chemical synthesis in carbon 4 or 3 in one of the aromatic rings of the structure where different ions were added, ensuring a variability of products. It was possible to observe results that indicate the possibility of these compounds acting through the cyclooxygenase 2 mechanism, which, in addition to being involved in inflammatory responses, also acts by helping sodium reabsorption. The amine group present in thiadiazine analogs confers hydrophilic characteristics to the substances, but this primary characteristic has been altered due to alterations and insertions of other ligands. The characteristics of the analogs generally allow easy intestinal absorption, reduce possible hepatic toxic effects, and enable possible neurological and anti-inflammatory action. The antibacterial activity tests showed a slight direct action, mainly of the IJ23 analog. Some compounds were able to modify the action of the antibiotics gentamicin and norfloxacin against multi-drug resistant strains, indicating a possible synergistic action. CONCLUSIONS: Among all the results obtained in the study, the relevance of thiadiazine analogs as possible coadjuvant drugs in the antibacterial, anti-inflammatory, and neurological action with low toxicity is clear. Need for further studies to verify these effects in living organisms is not ruled out.

Selectivity of herbicides applied to Brazilian tree species at post-emergence

The presence of weeds in silvicultural systems has been considered one of the main obstacles to the success of projects designed to recover degraded areas. The aim of this study was to evaluate the selectivity of herbicides applied at post-emergence in the initial growth of seedlings of capixingui (Croton floribundus), açoita-cavalo (Luehea divaricata), and guaritá (Astronium graveolens), in the municipalities of Jaboticabal and Junqueirópolis, state of São Paulo. The experimental design was completely randomized, with four replications, and the treatments consisted of herbicides (g a.i.·ha-1) clethodim + phenoxaprop-p-ethyl (50 + 50), sethoxydim (184), quizalofop-p-ethyl (75), nicosulfuron (50), fluazifop-p-butyl (125), fomesafen (225), haloxyfop-methyl (48), bentazon (720), chlorimuron-ethyl (15), in addition to control without herbicide. The characteristics analyzed were: plant height increase and visual phytointoxication at 7, 14, 21, 28, 35, and 42 days after herbicide application. At the end of the experiment, the shoots of the plants were removed to assess shoot dry matter. The herbicides clethodim + fenoxaprop-p-ethyl, fluazifop-p-butyl, and quizalofop-p-ethyl showed selective potential for the species capixingui, açoita-cavalo, and guaritá. The herbicide chlorimuron-ethyl caused mild intoxication symptoms when applied to seedlings of capixingui and açoita-cavalo; also, it was not selective for the guaritá species grown in Jaboticabal. All species showed selectivity to the herbicides sethoxydim, fomesafen, haloxyfop-methyl, and nicosulfuron, as their growth and initial development were not influenced. The herbicide bentazon caused high percentages of injury to açoita-cavalo plants in both cultivation places, but it did not influence the growth and development of the species.

[Taurolidine for the prevention of catheter-related infections in children with intestinal insufficiency: preliminary experience in a Chilean tertiary hospital]. / Taurolidina para prevenir infecciones asociadas a catéter venoso central en niños con insuficiencia intestinal: experiencia preliminar en un hospital terciario chileno.

BACKGROUND: Taurolidine is a molecule with anti-endotoxic, anti-microbial and anti-inflammatory properties that inhibits bacterial adhesion, allowing for its use as lock therapy for the prevention of catheter-related bloodstream infections (CRBSI) in long-term central venous catheters (CVC). AIM: To report a preliminary experience, the first one in Chile, using lock therapy with taurolidine for the prevention of CRBSI and to report its efficacy. METHOD: A taurolidine-based solution was instilled in the CVC of three children with intestinal insufficiency dependent on parenteral nutrition, attended in a Chilean tertiary hospital, and the rate of CRBSI before and after its use was compared in retrospect. RESULTS: In the two patients who started lock therapy immediately after the installation of their CVC, the rate of CRBSI was brought to zero, whereas in the third patient, who had a 9 months-old CVC with a recurrent CRBSI history, an intercurrent CRBSI forced discontinuation of the prophylaxis. CONCLUSIONS: Lock therapy with a taurolidine-based solution prevented CRBSIs when it was begun immediately after installing the CVC, in contrast with an old CVC with a history of recurrent CRBSIs.

Taurolidina para prevenir infecciones asociadas a catéter venoso central en niños con insuficiencia intestinal: experiencia preliminar en un hospital terciario chileno / Taurolidine for the prevention of catheter-related infections in children with intestinal insufficiency: preliminary experience in a Chilean tertiary hospital

INTRODUCCIÓN: Taurolidina es una molécula con propiedades anti-endotóxicas, antimicrobianas y anti-inflamatorias, que inhibe la adhesión bacteriana, lo que ha permitido usarla como terapia de sellado en catéter venoso central de larga duración (CVC) para prevenir infecciones del torrente sanguíneo asociadas a CVC (ITS-CVC). OBJETIVO: Dar a conocer una experiencia preliminar, la primera en Chile, con taurolidina como terapia de sellado para prevenir ITS-CVC y reportar su eficacia. MÉTODO: Se instiló una solución en base a taurolidina en el CVC de tres niños con insuficiencia intestinal, dependientes de alimentación parenteral, atendidos en un hospital terciario de la Región de Valparaíso, y se comparó la tasa de ITS-CVC antes y después de su uso mediante un análisis retrospectivo. RESULTADOS: en los dos pacientes que iniciaron terapia de sellado inmediatamente después de instalado el CVC, la tasa de ITS-CVC se logró llevar a cero, mientras que, en el tercero, portador de un CVC instalado 9 meses antes, con ITS-CVC recurrentes, un nuevo episodio de ITS-CVC obligó a suspender la profilaxis. CONCLUSIONES: La terapia de sellado con solución en base a taurolidina previno las ITS-CVC cuando ésta se inició al momento de instalarse el CVC, no así en un CVC antiguo con ITS-CVC recurrentes.

BACKGROUND: Taurolidine is a molecule with anti-endotoxic, anti-microbial and anti-inflammatory properties that inhibits bacterial adhesion, allowing for its use as lock therapy for the prevention of catheter-related bloodstream infections (CRBSI) in long-term central venous catheters (CVC). AIM: To report a preliminary experience, the first one in Chile, using lock therapy with taurolidine for the prevention of CRBSI and to report its efficacy. METHOD: A taurolidine-based solution was instilled in the CVC of three children with intestinal insufficiency dependent on parenteral nutrition, attended in a Chilean tertiary hospital, and the rate of CRBSI before and after its use was compared in retrospect. RESULTS: In the two patients who started lock therapy immediately after the installation of their CVC, the rate of CRBSI was brought to zero, whereas in the third patient, who had a 9 months-old CVC with a recurrent CRBSI history, an intercurrent CRBSI forced discontinuation of the prophylaxis. CONCLUSIONS: Lock therapy with a taurolidine-based solution prevented CRBSIs when it was begun immediately after installing the CVC, in contrast with an old CVC with a history of recurrent CRBSIs.

[Taurolidine, an antiseptic for the prevention of central venous catheter-related infections]. / Taurolidina, un antiséptico para la prevención de infecciones asociadas a catéter venoso central.

Taurolidine is a broad-spectrum antiseptic used as lock therapy solution in adult and pediatric patients with long term central venous catheters (CVC) for the prevention of catheter related bloodstream infections (CRBSI). Taurolidine doesn't induce the resistant development and has only minor and brief side effects, which makes it an alternative both as a lock therapy and for the prevention of CRBSI in this group of patients.

Taurolidina, un antiséptico para la prevención de infecciones asociadas a catéter venoso central / Taurolidine, an antiseptic for the prevention of central venous catheter-related infections

Resumen Taurolidina es un antiséptico de amplio espectro usado como solución de terapia de sellado (lock therapy) en adultos y niños portadores de catéter venoso central de larga duración (CVC) para prevenir las infecciones asociadas a CVC (IACVC). No induce desarrollo de resistencia y tiene efectos adversos leves y fugaces, lo que lo convierte en una alternativa, tanto como terapia de sellado como para la profilaxis de las IACVC, en este grupo de pacientes.

Taurolidine is a broad-spectrum antiseptic used as lock therapy solution in adult and pediatric patients with long term central venous catheters (CVC) for the prevention of catheter related bloodstream infections (CRBSI). Taurolidine doesn't induce the resistant development and has only minor and brief side effects, which makes it an alternative both as a lock therapy and for the prevention of CRBSI in this group of patients.

Cefazolin-gentamicin versus taurolidine-citrate for the prevention of infection in tunneled central catheters in hemodialysis patients: A quasi-experimental trial.

BACKGROUND: Catheter-related bloodstream infection (CR-BSI) is one of various complications related to hemodialysis (HD). As a result of the high rate of infection, the use of lock solutions for the prevention of CR-BSI has been studied. However, adverse effects of lock solution, such as increased emergence of strains resistant to antibiotics, which is an important concern, need to be investigated further. The aim of this study was to compare the efficacy of lock solution using a combination of cefazolin and gentamicin versus taurolidine and citrate in reducing CR-BSI in patients undergoing HD and to identify any adverse effects. METHODS: A prospective observational study was performed at two dialysis centers. Patients using new tunneled central venous catheters (CVC) for HD were included. Patients with a tunneled CVC were assigned to receive either antibiotic lock solution (group 1: gentamicin 7mg/ml+cefazolin 12mg/ml+heparin 3500IU/ml) or lock solution with TauroLock-Hep500 (group 2: taurolidine citrate 4%+heparin 500 IU/ml) during the inter-dialysis period. The patients were allocated to these groups according to the hemodialysis center they were attending. RESULTS: A total of 145 CVCs were implanted in 127 patients and were followed for 15 months: 77 CVCs (65 patients) were placed in group 1 and 68 CVCs (62 patients) in group 2. There was no difference between the two groups with regard to CR-BSI (events per 1000 catheter-days: group 1=0.79, group 2=1.10; p=0.18) or exit site infection rates (events per 1000 catheter-days: group 1=2.45, group 2=1.83; p=0.37). The groups differed in ESI pathogens, with gram-positive oxacillin-resistant pathogens more frequent in group 1 (31.8% vs. 5.0%; p=0.003). The two groups were similar in mechanical complications. In the Cox regression analysis, the internal jugular vein site was a protective factor for all catheter removal complications (hazard ratio (HR) 0.41, 95% confidence interval (CI) 0.19-0.91) and mechanical complications (HR 0.16, 95% CI 0.065-0.41); only ESI was a risk factor for all catheter removal complications (HR 1.79, 95% CI 1.04-3.07) and mechanical complications (HR 5.64, 95% CI 1.65-19.3). CONCLUSIONS: The efficacy of both lock solutions was similar in preventing infections related to tunneled CVCs for HD. However, there were more oxacillin-resistant strains in patients who received antibiotic lock solution. Further studies are required to determine the optimal drug regimen and concentrations for lock solution and the associated adverse effects.

Impact of insect growth regulators on the predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae).

The generalist predator Ceraeochrysa cincta (Schneider) (Neuroptera: Chrysopidae) is an important biological control agent of several arthropod pests in different agroecosystems. This study assessed the lethal and sublethal effects of six insect growth regulators sprayed on first-instar larvae of C. cincta. Lufenuron and diflubenzuron were highly harmful to first-instar larvae of C. cincta, causing 100 % of mortality before they reached the second instar. Buprofezin caused ~25 % mortality of the larvae and considerably reduced the fecundity and longevity of the insects, but substantially increased the proportion of females in the surviving population of C. cincta. Methoxyfenozide and tebufenozide did not affect the duration and survival of the immature stages, but methoxyfenozide significantly reduced the fecundity and longevity of the insects. Pyriproxyfen reduced the survival of the larval stage by 19.5 %, but did not affect the development, survival and reproduction of the surviving individuals. Based on reduction coefficient, the insecticides diflubenzuron and lufenuron were considered harmful to C. cincta, whereas buprofezin and methoxyfenozide were slightly harmful and tebufenozide and pyriproxyfen were harmless. The estimation of life-table parameters indicated that buprofezin and methoxyfenozide significantly reduced the R o , r and λ of C. cincta, whereas pyriproxyfen and tebufenozide caused no adverse effect on population parameters, indicating that these insecticides could be suitable for use in pest management programs towards the conservation and population increase of the predator in agroecosystems. However, more studies should be conducted to evaluate the compatibility of these insecticides with the predator C. cincta under semi-field and field conditions.

Molecular docking and molecular dynamics simulation studies of Trypanosoma cruzi triosephosphate isomerase inhibitors. Insights into the inhibition mechanism and selectivity.

Trypanosoma cruzi (T. cruzi) triosephosphate isomerase (TcTIM) is a glycolytic enzyme essential for parasite survival and has been considered an interesting target for the development of new antichagasic compounds. The homodimeric enzyme is catalytically active only as a dimer. Interestingly, significant differences exist between the human and parasite TIMs interfaces with a sequence identity of 52%. Therefore, compounds able to specifically disrupt TcTIM but not Homo sapiens TIM (hTIM) dimer interface could become selective antichagasic drugs. In the present work, the binding modes of 1,2,4-thiadiazol, phenazine and 1,2,6-thiadiazine derivatives to TcTIM were investigated using molecular docking combined with molecular dynamics (MD) simulations. The results show that phenazine and 1,2,6-thiadiazine derivatives, 2 and 3, act as dimer-disrupting inhibitors of TcTIM having also allosteric effects in the conformation of the active site. On the other hand, the 1,2,4-thiadiazol derivative 1 binds into the active site causing a significant decrease in enzyme mobility in both monomers. The loss of conformational flexibility upon compound 1 binding suggests that this inhibitor could be preventing essential motions of the enzyme required for optimal activity. The lack of inhibitory activity of 1 against hTIM was also investigated and seems to be related with the high mobility of hTIM which would hinder the formation of a stable ligand-enzyme complex. This work has contributed to understand the mechanism of action of this kind of inhibitors and could result of great help for future rational novel drug design.

New chemotypes as Trypanosoma cruzi triosephosphate isomerase inhibitors: a deeper insight into the mechanism of inhibition.

CONTEXT: Triosephosphate isomerase (TIM) is a ubiquitous enzyme that has been targeted for the discovery of new small molecular weight compounds used against Trypanosoma cruzi, the causative agent of Chagas disease. We have identified phenazine and 1,2,6-thiadiazine chemotypes as novel inhibitors of TIM from T. cruzi (TcTIM). OBJECTIVE: Study the mechanism of TcTIM inhibition by a phenazine derivative and by a 1,2,6-thiadiazine derivative. METHODS: We performed biochemical and theoretical molecular docking studies to characterize the interaction of the derivatives with wild-type and mutant TcTIM. RESULTS AND CONCLUSION: At low micromolar concentrations, the compounds induce highly selective irreversible inactivation of parasitic TIM. The molecular docking simulations indicate that the phenazine derivative likely interferes with the association of the two monomers of the dimeric enzyme by locating at the dimer interface, while 1,2,6-thiadiazine could act as an inhibitor binding to a region surrounding Cys-118.

Dibenzo[1,2,5]thiadiazepines are non-competitive GABAA receptor antagonists.

A new process for obtaining dibenzo[c,f][1,2,5]thiadiazepines (DBTDs) and their effects on GABA(A) receptors of guinea pig myenteric neurons are described. Synthesis of DBTD derivatives began with two commercial aromatic compounds. An azide group was obtained after two sequential reactions, and the central ring was closed via a nitrene to obtain the tricyclic sulfonamides (DBTDs). Whole-cell recordings showed that DBTDs application did not affect the holding current but inhibited the currents induced by GABA (I(GABA)), which are mediated by GABA(A) receptors. These DBTDs effects reached their maximum 3 min after application and were: (i) reversible, (ii) concentration-dependent (with a rank order of potency of 2c = 2d > 2b), (iii) mediated by a non-competitive antagonism, and (iv) only observed when applied extracellularly. Picrotoxin (which binds in the channel mouth) and DBTDs effects were not modified when both substances were simultaneous applied. Our results indicate that DBTD acted on the extracellular domain of GABA(A) channels but independent of the picrotoxin, benzodiazepine, and GABA binding sites. DBTDs used here could be the initial model for synthesizing new GABA(A) receptor inhibitors with a potential to be used as antidotes for positive modulators of these receptors or to induce experimental epilepsy.

Comparação entre o sumatriptano, a trimebutina, o meloxicam e a associação dos três fármacos no tratamento agudo de enxaqueca / Comparison among sumatriptane, trimebutine, meloxicam and the association of those drugs in the acute treatment of migraine

JUSTIFICATIVA E OBJETIVOS: A crise aguda de migrânea geralmente leva a grande incapacidade econômica e social para aqueles que sofrem deste transtorno. A fisiopatologia é complexa e envolve múltiplos mecanismos centrais e periféricos. O tratamento agudo tem como objetivo aliviar a dor e os fenômenos associados como a náusea e fotofobia, sem causar efeitos adversos importantes. Apesar do desenvolvimento de fármacos específicos como os triptanos, para o tratamento agudo, a sua eficácia ainda é baixa. O objetivo deste estudo foi comparar a eficácia e a tolerância da trimebutina, meloxicam, sumatriptano e a associação dos três fármacos no tratamento das crises agudas de migrânea de moderada a forte intensidade.MÉTODO: Após aprovação pelo Comitê de Ética das Instituições foram incluídos neste estudo prospectivo, duplamente encoberto e aleatório, 50 pacientes, sendo 43 mulheres e 7 homens, com idade entre 18 e 65 anos, portadores de migrânea com ou sem aura, que utilizavam medicação profilática, exceto anti-inflamatórios não esteroides (AINES). Foram tratadas quatro crises de migrânea de moderada a forte intensidade de cada paciente, com 200 mg de trimebutina, 50 mg de sumatriptano, 15 mg de meloxicam ou com a associação de 200 mg de trimebutina, 50 mg de sumatriptano e 15 mg de meloxicam. Os pacientes foram aleatorizados em 4 grupos de acordo com a ordem de chegada, de modo que o primeiro paciente incluído recebeu trimebutina para a primeira crise, sumatriptano para a segunda crise, meloxicam para a terceira crise e a associação entre os 3 fármacos para a quarta crise. O segundo paciente incluído recebeu sumatriptano para a primeira crise, meloxicam para a segunda superior a cada um desses fármacos isolados para controlar a dor, as náuseas e a fotofobia nas crises agudas de migrânea de moderada a forte intensidade. Além disso, a combinação dos fármacos apresentou maior incidência de efeitos adversos.crise, a associação para a terceira crise e a trimebutina para a quarta crise, e assim sucessivamente. A intensidade da crise de migrânea foi avaliada a partir da ingestão da cápsula com escala categorizada verbal na qual: 0 - sem dor, 1 - cefaleia leve, 2 - cefaleia moderada e 3 - cefaleia intensa. Cada paciente foi orientado para preencher o relatório de crise para cada crise tratada, na qual anotava a intensidade da cefaleia, a presença de náusea, fotofobia e dos efeitos adversos, e o uso da medicação de resgate, 100 mg de indometacina por via retal. RESULTADOS: Completaram o estudo 42 pacientes. Em uma hora 9,5% dos pacientes que utilizaram a associação dos fármacos estavam livres da dor, comparados com 14,2% com a trimebutina e sumatriptano e 2,4% com o meloxicam (p = 0,479). Em duas horas 21,4% dos pacientes que usaram a associação estavam livres da dor, comparados com 11,9% com a trimebutina, 26,1% com sumatriptano e 23,8% com o meloxicam (p = 0,555). Tanto a associação trimebutina, sumatriptano e meloxicam como os fármacos trimebutina, sumatriptano e meloxicam isolados foram efetivos para controlar a náusea e fotofobia após 1 e 2h para náusea (p = 0,157 e 0,587) e fotofobia (p = 0,671 e 0,929, embora sem diferença estatisticamente significativa entre eles. Dez pacientes em uso da associação dos fármacos, 6 em uso da trimebutina, 5 em uso do sumatriptano e 5 em uso do meloxicam relataram efeitos colaterais. CONCLUSÃO: Este estudo demonstrou que a associação sumatriptano, meloxicam e trimebutina não foi superior a cada um desses fármacos isolados para controlar a dor, as náuseas e a fotofobia nas crises agudas de migrânea de moderada a forte intensidade. Além disso, a combinação dos fármacos apresentou maior incidência de efeitos adversos.

BACKGROUND AND OBJECTIVES: Acute migraine crisis often leads to major economic and social disability for those suffering from such syndrome. Pathophysiology is complex involving several central and peripheral mechanisms. The acute treatment aims at evaluating pain and associated phenomena, such as nausea and photophobia, without causing major adverse effects. Notwithstanding the development of specific drugs for the acute treatment, such as triptanes, their efficacy is still low. This study aimed at comparing efficacy and tolerance of trimebutine, meloxicam, sumatriptane and the association of such drugs to treat moderate to severe acute migraine crises.METHOD: After the Institutions? Ethics Committee approval, participated in this prospective, double-blind and randomized study 50 patients, being 43 females and 7 males, aged between 18 and 65 years, with migraine with or without aura, under prophylactic medication, except non-steroid anti-inflammatory drugs (NSAIDS). Patients were treated for 4 moderate to severe migraine crises with 200 mg trimebutine, 50 mg sumatriptane, 15 mg meloxicam, or with the association of 200 mg trimebutine, 50 mg sumatriptane and 15 mg meloxicam. Patients were randomized in 4 groups according to their arrival, so that the first patient included received trimebutine for the first crisis, sumatriptane for the second crisis, meloxicam for the third crisis and the association of the three drugs for the fourth crisis. The second patient included received sumatriptane for the first crisis, meloxicam for the second crisis, the association for the third crisis and trimebutine for the fourth crisis, and so on and so forth. Migraine crisis intensity was evaluated as from the ingestion of the first tablet with verbal categorized scale where: 0 = no pain, 1 = mild headache, 2 = moderate headache, 3 = severe headache. All patients were oriented to fill a crisis report for each treated crisis, where they would record headache intensity, presence of nausea, photophobia and adverse effects and the use of rescue medication, 100 mg of rectal indometacin.RESULTS: Forty-two patients completed the study. In one hour 9.5% of patients using the association of drugs were free of pain, as compared to 14.2% with trimebutine and sumatriptane and 2.4% with meloxicam (p = 0.479). In two hours 21.4% of patients using the association were free of pain, as compared to 11.9% with trimebutine, 26.1% with sumatriptane and 23.6% with meloxicam (p = 0.555). Both the association of trimebutine, sumatriptane and meloxicam and trimebutine, sumatriptane and meloxicam alone were effective to control nausea and photophobia after 1 and 2 h for nausea (p = 0.157 and 0.587) and photophobia (p = 0.671 and 0.929) although without statistically significant difference among them. Ten patients under the association of drugs, 6 under trimebutine, 5 under sumatriptane and 5 under meloxicam have reported side effects. CONCLUSION: This study has shown that the association of sumatriptane, meloxicam and trimebutine was not better than each of those drugs alone to control pain, nausea and photophobia during moderate to severe migraine crises. In addition, the combination of drugs has shown a higher incidence of adverse effects.

MSPD procedure for determining buprofezin, tetradifon, vinclozolin, and bifenthrin residues in propolis by gas chromatography-mass spectrometry.

A simple and effective extraction method based on matrix solid-phase dispersion (MSPD) was developed to determine bifenthrin, buprofezin, tetradifon, and vinclozolin in propolis using gas chromatography-mass spectrometry in selected ion monitoring mode (GC-MS, SIM). Different method conditions were evaluated, for example type of solid phase (C(18), alumina, silica, and Florisil), the amount of solid phase and eluent (n-hexane, dichloromethane, dichloromethane-n-hexane (8:2 and 1:1, v/v) and dichloromethane-ethyl acetate (9:1, 8:2 and 7:3, v/v)). The best results were obtained using 0.5 g propolis, 1.0 g silica as dispersant sorbent, 1.0 g Florisil as clean-up sorbent, and dichloromethane-ethyl acetate (9:1, v/v) as eluting solvent. The method was validated by analysis of propolis samples fortified at different concentration levels (0.25 to 1.0 mg kg(-1)). Average recoveries (four replicates) ranged from 67% to 175% with relative standard deviation between 5.6% and 12.1%. Detection and quantification limits ranged from 0.05 to 0.10 mg kg(-1) and 0.15 to 0.25 mg kg(-1) propolis, respectively.

Efecto de derivados de la tiadiazina sobre la capacidad infectiva de promastigotes de Leishmania amazonensis / Effects of thiadiazine derivatives on the infective capacity of Leishamia amazonensis promastigotes

Se evaluó la capacidad infectiva de promastigotes de Leishmania amazonensis al ser tratados con una serie de 10 derivados de la tiadiazina. Los parásitos fueron incubados durante 24 h con 1 o 0,1 mg/mL de cada compuesto y posteriormente, se infectaron macrófagos peritoneales de ratones BALB/c en cultivos. Todos los compuestos causaron una reducción de la capacidad infectiva de los parásitos mayor que 50 por ciento. El producto T1O fue el que causó un mayor efecto, disminuyendo la infección en 92,8 por ciento de infección(AU)

Alkyl-linked bis-THTT derivatives as potent in vitro trypanocidal agents.

The effect of several alkyl-linked bis tetrahydro-(2H)-1,3,5-thiadiazine-2-thione (bis-THTT) on Leishmania donovani, Trypanosoma brucei rhodesiense, and Plasmodium falciparum is reported. Most of the compounds exhibited a potent activity against the three parasitic strains but the best in vitro activity profiles were found against T. b. rhodesiense with IC(50) values ranging between 0.3 and 4 microM for the most active compounds.

Quantitative Structure Antitumoral-Activity Relationships of Thiadiazinthione Derivatives Using the Novel Hybrid Molecular Index pMRc / s. t

The recently defined molar-refractivity-partition index was applied to a family of 1,3,5- thiadiazin-2-thione derivatives in order to establish quantitative structure-antitumoral models. The goal of this effort is to establish the relationships between the structure and biological response of these compounds. Method. After the splitting of the sample in two sets, their indices were correlated against the measured biological activity. The combined use of our index with others had been able to describe not only the topologic but also the London dispersive forces of any fragment in relation to the biological response of the sets. Results. The obtained models showed correlation coefficients of 0,87 and 0,81 respectively linking structural and biological features of the molecules. The mean relative error values were less than 7 percent. According to the models, the activity of the first sample is related mostly to molecular topology and dispersive forces. Sample two activity was associated to the size and branching of the substituents, and also to the London forces. Conclusion. The index was able to discriminate between pure topological features and those related to dispersive forces(AU)

Synthesis and antiprotozoan evaluation of new alkyl-linked bis(2-thioxo-[1,3,5]thiadiazinan-3-yl) carboxylic acids.

Two new series of several alkyl-linked bis(2-thioxo-[1,3,5]thiadiazinan-3-yl) carboxylic acids were synthesized in a two step procedure from the corresponding alkyl bis-dithiocarbamic salt intermediary. The novel compounds were evaluated for their activity in vitro against Trypanosoma cruzi strain CL (clone CL B5) and Trichomonas vaginalis strain JH 31A.

Quantitative structure antitumoral-activity relationships of thiadiazinthione derivatives using the novel hybrid molecular index pMRchi.

PURPOSE: The recently defined molar-refractivity-partition index was applied to a family of 1,3,5- thiadiazin-2-thione derivatives in order to establish quantitative structure-antitumoral models. The goal of this effort is to establish the relationships between the structure and biological response of these compounds. METHOD: After the splitting of the sample in two sets, their indices were correlated against the measured biological activity. The combined use of our index with others had been able to describe not only the topologic but also the London dispersive forces of any fragment in relation to the biological response of the sets. RESULTS: The obtained models showed correlation coefficients of 0.87 and 0.81 respectively linking structural and biological features of the molecules. The mean relative error values were less than 7%. According to the models, the activity of the first sample is related mostly to molecular topology and dispersive forces. Sample two activity was associated to the size and branching of the substituents, and also to the London forces. CONCLUSION: The index was able to discriminate between pure topological features and those related to dispersive forces.