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1.
Onco Targets Ther ; 16: 983-994, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38021448

RESUMO

Background: Ligustilide (LIG) and n-butylphthalide (NBP) have neuroprotective effects in cerebral ischemia; however, their roles in gliomas are not well-known.This study aimed to explore the anti-glioma effects of LIG and NBP individually and the synergistic effects of temozolomide (TMZ) via the PI3K/Akt Signaling Pathway. Materials and Methods: Cytotoxicity of LIG and NBP alone and in combination with TMZ in U251 cells was determined using the CCk-8. The effect of compounds alone or in combination on cell migration was detected using the wound healing assay, and the invasion was evaluated by transwell assays, respectively. Cell apoptosis was quantified by flow cytometry and the changed expressions of proteins were detected by Western blotting. Results: The results showed that LIG and NBP significantly inhibited the growth of U251 cells at concentrations of 4-10 µg/mL and 1.5-6 µg/mL in a dose-dependent manner (p<0.05, p<0.01). The combination of 20 µg/mL TMZ with LIG in the concentration range of 4-10 µg/mL or with NBP of 0.5-6 µg/mlachieved synergistic effect towardsU251 cells. LIG and NBP, alone or in combination with TMZ, markedly inhibited cell invasion (p< 0.001) and enhanced apoptosis (p< 0.05). The combination of TMZ with LIG or NBP markedly inhibited cell migration (p< 0.001). Western blot analysis showed that LIG, NBP, and TMZ, alone and in combination, significantly decreased the expression of Bcl-2, p-PI3K, and p-Akt, and increased the expression of Bax. Conclusion: Both LIG and NBP exert anti-glioma effects on their own through the PI3K/Akt pathway and enhance TMZ-mediated anti-glioma efficiency via the same pathway.

2.
Infect Drug Resist ; 15: 7043-7052, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36483145

RESUMO

Pandoraea sputorum (P. sputorum) infection is of great concern as these gram-negative bacillus species are multidrug-resistant and usually isolated from the patients' respiratory tract suffering from cystic fibrosis (CF). A few cases of infection have also been reported in non-CF patients due to its rare pathogenic nature with unclear and overlapping clinical, biochemical, and microbiological characteristics with other species. Here, we report an unusual case of a 46-year-old non-CF female, who presented with multiple pelvic fractures, acute traumatic brain injury, multiple rib fractures, and multiple burns (18% of the total body surface area, II°) by the collapse of a brick kiln, suffered from P. sputorum sepsis due to wound infection. Pandoraea species were isolated both from her blood and wound secretion. Antibiotic susceptibility testing indicated susceptibility to imipenem, tetracyclines, sulfamethoxazole, and ampicillin/sulbactam but resistance to meropenem, quinolones, aminoglycosides, and other beta-lactams. 16S ribosomal RNA (rRNA) PCR assays and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) were used to confirm the bacteria as P. sputorum. After effective anti-infection of intravenous antibiotics (imipenem 1.0 Q8H with tigecycline 50 mg Q12H for 14 days), wound care, and other comprehensive treatment for two months, the patient improved and was discharged from the hospital eventually. After reviewing the literature, we observed that the susceptibility results of Pandoraea species were often multidrug-resistant and had a unique pattern of being resistant to meropenem but sensitive to imipenem. Biofilm formation, carbapenemase production, and unique gene procession differed from the environmental isolates could help explain its resistance. This case report highlights the potential virulence of Pandoraea species as a pathogen in patients with no underlying disease. Although they are often multi-resistant, imipenem can be a preferred treatment for Pandoraea species in the earliest identification steps.

3.
Polymers (Basel) ; 14(1)2021 Dec 30.
Artigo em Inglês | MEDLINE | ID: mdl-35012164

RESUMO

Geopolymer concrete (GC) has been gaining attention in research and engineering circles; however, it is a brittle material with poor tensile performance and crack resistance. To address these problems, we introduced fibers into GC. In this study, axial compression and scanning electron microscope (SEM) tests were carried out on polyvinyl alcohol (PVA) short fiber reinforced low-calcium fly ash-slag-based geopolymer concrete (PFRGC). The ratio of PVA short fibers and low-calcium fly ash on the compression behavior of fiber reinforced geopolymer concrete (FRGC) were investigated and discussed. The test results show that PVA fibers play a bridging role in the cracks of the specimen and bear the load together with the matrix, so the addition of PVA fibers delayed the crack propagation of GC under axial compression. However, with the increase of low-calcium fly ash/PVA fibers, the number of unreacted fly ash particles in PFRGCs increases. Too many unreacted fly ash particles make GC more prone to micro-cracks during loading, adversely affecting compressive properties. Therefore, the axial compressive strength, elastic modulus, and Poisson's ratio of GC decrease with the increasing low-calcium fly ash/PVA fibers.

4.
Sensors (Basel) ; 18(12)2018 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-30477191

RESUMO

Strengthening existing reinforced concrete (RC) columns using a partial wrapping strengthening technique (PWST) by fiber-reinforced polymer (FRP) strips has been widely implemented. However, compared with the confinement mechanism of confined concrete in columns strengthened with the FRP full wrapping strengthening technique (FWST), the confinement mechanism of confined concrete in FRP partially wrapped columns is less understood. This paper presents the results of an experimental investigation into the behavior of confined concrete in FRP partially wrapped square columns under axial compression. The effects of FRP strip width and thickness on stress⁻strain behavior were thoroughly investigated. The novel particle image velocimetry (PIV) non-contact strain sensing technique was adopted to measure the strain in the specimens. Results show that the axial strains as well as the hoop strains are generally larger at the mid-plane of adjacent FRP strips than those at the mid-plane of each FRP strip, and considerable variation in hoop strains along the height of the specimens was observed. Comparisons between the experimental results and predictions by existing design-oriented stress⁻strain models were carried out to examine the accuracy of the models. A new design-oriented stress⁻strain model is proposed for confined concrete in FRP partially wrapped square columns and the comparisons between laboratory results and predictions from the proposed model show that the proposed model is superior to the existing models.

5.
Infect Dis Poverty ; 7(1): 9, 2018 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-29409536

RESUMO

BACKGROUND: Chemotherapy for schistosomiasis has been around for 100 years. During the past century, great efforts have been made to develop new antischistosomal drugs from antimonials to nonantimonials, and some of these have been used extensively in clinical treatment. With the exception of a few drugs, such as oxamniquine and metrifonate, most of the antischistosomals developed in the pre-praziquantel period have variable limitations with respect to safety and efficacy. Although oxamniquine and metrifonate have been used for schistosomiasis control, they are only effective against Schistosoma mansoni and S. haematobium, respectively. Currently, praziquantel is the only drug used for treatment of all five species of human schistosomes. In this review, the pharmacological and immunological effects of praziquantel against S. japonicum are summarized and discussed. MAIN TEXT: From the end of the 1970s until the 2000s, scientists have conducted a series of experimental studies on the effects of praziquantel against S. japonicum. These have included examining its unique pharmacological action on schistosomes, the characteristics in susceptibility of the different developmental stages of schistosomes to the drug, the relationship between plasma concentration of the drug and efficacy, the impact of host factors on cidal action of the drug, prevention and early treatment of schistosomal infection, as well as praziquantel-resistant schistosomiasis. CONCLUSION: The effects of praziquantel against S. japonicum, as elucidated by the experimental studies that are reviewed in this paper, may have some reference significance for the development of new antischistosomals.


Assuntos
Praziquantel/farmacologia , Schistosoma japonicum/efeitos dos fármacos , Schistosoma japonicum/imunologia , Esquistossomose/imunologia , Esquistossomicidas/farmacologia , Animais , Resistência a Medicamentos , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Camundongos , Praziquantel/sangue , Schistosoma mansoni/efeitos dos fármacos , Esquistossomose/tratamento farmacológico , Esquistossomose/parasitologia
6.
Dev Cell ; 41(1): 59-71.e4, 2017 04 10.
Artigo em Inglês | MEDLINE | ID: mdl-28399401

RESUMO

Autophagy is essential for maintaining glucose homeostasis, but the mechanism by which energy deprivation activates autophagy is not fully understood. We show that Mec1/ATR, a member of the DNA damage response pathway, is essential for glucose starvation-induced autophagy. Mec1, Atg13, Atg1, and the energy-sensing kinase Snf1 are recruited to mitochondria shortly after glucose starvation. Mec1 is recruited through the adaptor protein Ggc1. Snf1 phosphorylates Mec1 on the mitochondrial surface, leading to recruitment of Atg1 to mitochondria. Furthermore, the Snf1-mediated Mec1 phosphorylation and mitochondrial recruitment of Atg1 are essential for maintaining mitochondrial respiration during glucose starvation, and active mitochondrial respiration is required for energy deprivation-activated autophagy. Thus, formation of a Snf1-Mec1-Atg1 module on mitochondria governs energy deprivation-induced autophagy by regulating mitochondrial respiration.


Assuntos
Proteínas Relacionadas à Autofagia/metabolismo , Autofagia , Metabolismo Energético , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Mitocôndrias/metabolismo , Proteínas Quinases/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Autofagia/efeitos dos fármacos , Respiração Celular/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glucose/farmacologia , Mitocôndrias/efeitos dos fármacos , Modelos Biológicos , Fosforilação/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Saccharomyces cerevisiae/efeitos dos fármacos
7.
Int J Parasitol ; 47(4): 171-183, 2017 03.
Artigo em Inglês | MEDLINE | ID: mdl-28012717

RESUMO

More than 95years ago Schistosoma pigment had been deemed as a degradation product of haemoglobin. Until the 1950s, scientists initiated to pay attention to understand the hematophagous habit of schistosomes, and to study the degradation of haemoglobin as well as the formation of hemozoin inside the gut of the worms. For a long time, the formation of hemozoin in both Plasmodium and in Schistosoma was considered to be the major route of heme detoxification, and hemozoin served a role in waste disposal. At the beginning of this century, the chemical structure of Schistosoma pigment was confirmed to be identical to that of malarial pigment (hemozoin) and its synthetic analogue, ß-hematin. Since then, studies on Schistosoma hemozoin have been investigated by some workers and the results showed that Schistosoma hemozoin may play important roles in pathogenicity, immune modulation, iron supply for egg formation, and interaction with some anti-schistosomal drugs. In this review, we briefly review and discuss the hematophagous habit of schistosomes, degradation of haemoglobin, formation of hemozoin in the worm gut, and possible roles of hemozoin.


Assuntos
Proteínas de Helminto/metabolismo , Hemeproteínas/metabolismo , Pigmentos Biológicos/metabolismo , Schistosoma/fisiologia , Animais , Proteínas de Helminto/química , Hemeproteínas/química , Hemoglobinas/metabolismo , Interações Hospedeiro-Patógeno , Humanos , Imunomodulação , Ferro/metabolismo , Pigmentos Biológicos/química , Virulência
8.
Parasitol Res ; 114(12): 4521-30, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26341799

RESUMO

The purpose of the present study is to understand the pharmacokinetic feature of mefloquine measured by erythrocytes and plasma in Schistosoma japonicum (S. j.)-infected mice and non-infected mice after oral administration of the drug at single doses. A high-performance liquid chromatography (HPLC) method was used to measure the plasma and erythrocyte concentrations of mefloquine at varying intervals posttreatment. Our results demonstrated that in non-infected mice treated orally with mefloquine at an ineffective dose of 50 mg/kg or effective dose of 200 mg/kg for 2-72 h, the erythrocyte-to-plasma ratios of mefloquine were 5.8-11.2 or 2-14.2. On the other hand, in S. j.-infected mice treated with the same single doses of the drug, the erythrocyte and plasma drug concentration ratios were 3.1-4.6 or 2.9-8.5, manifesting that either in infected mice or in non-infected mice that received oral mefloquine resulted in higher concentration of mefloquine in erythrocytes than that in plasma. Unexpectedly, under oral administration of mefloquine at a higher single dose of 200 mg/kg, the pharmacokinetic parameter C max values for plasma from S. j.-infected and non-infected mice were 1.6 ± 0.3 and 2.0 ± 0.4 µg/mL, respectively, which were below the determined in vitro LC50 (50 % lethal concentration) value of 4.93 µg/mL. Therefore, the plasma concentration of mefloquine may display a little effect against schistosomes during the treatment. Although the values of T 1/2 and AUC0-∞ for erythrocytes were significantly longer and higher in infected mice than those of corresponding non-infect mice that received the same single mefloqine dose of 50 mg/kg, the C max value was only 2.6 ± 0.4 µg/mL lower than the determined in vitro LC50, which may explain why this low single dose is ineffective against schistosomes in vivo. After administration of higher mefloquine dose of 200 mg/kg, the C max value for erythrocytes in infected mice was 30 % (7.4 ± 0.7 versus 10.7 ± 2.7 µg/mL) lower than that in the corresponding non-infected mice, but its level was above the determined in vitro LC95 (95 % lethal concentration) value of 6.12 µg/mL. Meanwhile, longer T 1/2 value of 159.2 ± 129.3 h in infected mice led to significant increase in AUC0-∞ value (1969.3 ± 1057.7 vs 486.4 ± 53.0 µg/mL·h), relative to corresponding non-infected mice. In addition, the mean residence time (MRT0-∞) in infected mice was also significantly longer than that in non-infected mice. All these results may beneficial for the treatment. According to the results, we suggest that higher ratios of mefloquine concentration in erythrocytes to plasma may offer a way to transport mefloquine to the worm gut through ingestion of erythrocytes by the worms, where the gut is the site for displaying the effect by mefloquine.


Assuntos
Eritrócitos/química , Mefloquina/administração & dosagem , Schistosoma japonicum/efeitos dos fármacos , Esquistossomose Japônica/parasitologia , Administração Oral , Animais , Eritrócitos/metabolismo , Humanos , Mefloquina/análise , Mefloquina/farmacocinética , Camundongos , Esquistossomose Japônica/tratamento farmacológico , Esquistossomose Japônica/metabolismo
9.
PLoS One ; 10(2): e0116976, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25643051

RESUMO

OBJECTIVE: This study was aimed at evaluating the clinical efficacy and safety of transcutaneous electrical acupoint stimulation (TEAS) to treat muscle spasticity after brain injury (Chinese Clinical Trial Registry: ChiCTR-TRC-11001310). METHODS: A total of 60 patients with muscle spasticity after brain injury were randomized to the following 3 groups: 100, 2, and 0 Hz (sham) TEAS. The acupoints Hegu (LI4)--Yuji (LU10) and Zusanli (ST36)--Chengshan (BL57) on the injured side were stimulated at 0, 2, or 100 Hz, 5 times per week for 4 weeks. The patients were followed up for 1 and 2 months after the treatments. The effects of the treatments on muscle spasticity at the wrist, thumb, the other 4 fingers, elbow, shoulder, knee, and ankle were evaluated by the Modified Ashworth Scale, and the effects on disability were assessed by the Disability Assessment Scale. The walking capability was evaluated by the Holden functional ambulation classification score. The overall performance was assessed by the Global Assessment Scale score and the improved Barthel Index. The safety of the treatments administered was also monitored. RESULTS: The wrist spasticity was significantly reduced from baseline at weeks 2, 3, and 4 of treatment and at the 1- and 2-month follow-up visits in the 100 Hz group (P < 0.01). Compared with 2 Hz or sham TEAS, 100 Hz TEAS decreased wrist spasticity at weeks 2, 3, and 4 of treatment and 1 month after treatment (P < 0.001). The other endpoints were not affected by the treatments. No treatment-emergent adverse events were reported during treatments and follow-up visits. CONCLUSIONS: TEAS appears to be a safe and effective therapy to relieve muscle spasticity after brain injury, although large-scale studies are required to further verify the findings. TRIAL REGISTRATION: Chinese Clinical Trial Registry ChiCTR-TRC-11001310 http://www.chictr.org.


Assuntos
Pontos de Acupuntura , Lesões Encefálicas/complicações , Espasticidade Muscular/complicações , Espasticidade Muscular/terapia , Segurança , Estimulação Elétrica Nervosa Transcutânea/efeitos adversos , Estimulação Elétrica Nervosa Transcutânea/métodos , Adolescente , Adulto , Método Duplo-Cego , Determinação de Ponto Final , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento , Punho/fisiopatologia , Adulto Jovem
10.
Zhonghua Jie He He Hu Xi Za Zhi ; 37(8): 588-91, 2014 Aug.
Artigo em Chinês | MEDLINE | ID: mdl-25351265

RESUMO

OBJECTIVE: To explore the shape and the location of mediastinal spaces (mediastinal lymph node locations) associated with conventional transbronchial needle aspiration technique (C-TBNA), and to determine the relationship between the mediastinal spaces and physiological and anatomical marks in trachea-bronchial lumen for choosing the puncture points of C-TBNA. METHODS: The chest HRCT images of 1 000 consecutive patients preparing for bronchoscopic examination were analyzed to determine the shape and the location of the mediastinal gap, and which physiological and anatomic markers in the airway were suitable for locating the mediastinal spaces and lymph nodes. Eighty-one groups of lymph nodes from 52 patients were punctured by endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) to verify the locating of puncture points by these markers for the mediastinal lymph nodes under general anesthesia. The needle was punctured into the wall of the airway first, and then the ultrasound was used to confirm if the needle was in the lymph nodes. RESULTS: Pretracheal space, aortic-left pulmonary window space, superior-carinal space and subcarinal space showed close relationship with C-TBNA biopsy for mediastinal lymph nodes. The pretracheal space could be located by the physiological and anatomic marks of aortic impression and aortic pulse points. The superior-carinal space was like a triangle and locating in 12 o'clock of the first ring of trachea. The 9-10 o'clock of the first ring of the trachea was the aortic-left pulmonary window. The 8-9 o'clock of the right main bronchus and middle bronchus was for subcarinal space. Eighty-one groups of lymph nodes from 52 patients were punctured by EBUS-TBNA according to the physiological and anatomic markers, and it showed that only 3 groups were missed by C-TBNA. No mediastinal bleeding and pneumomediastinum occurred. CONCLUSION: Mediastinal spaces(mediastianl lymph nodes) and physiological and anatomical marks within the airway had a relatively fixed relationship. These marks could be used for locating the mediastinal lymph nodes when C-TBNA was performed.


Assuntos
Biópsia por Agulha Fina , Linfonodos/anatomia & histologia , Brônquios , Humanos , Mediastino
11.
PLoS Negl Trop Dis ; 8(8): e3046, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25122121

RESUMO

BACKGROUND: Both tribendimidine and mebendazole are broad-spectrum drugs for anti-intestinal nematodes. We aim to assess the efficacy and safety of tribendimidine and mebendazole in patients with co-infection of Clonorchis sinensis and other helminths. METHOD: We performed a randomized open-label trial in Qiyang, People's Republic of China. Eligible participants were randomly assigned to one of four groups: (i) a single dose of 400 mg tribendimidine, (ii) 200 mg tribendimidine twice daily, (iii) 75 mg/kg praziquantel divided in four doses within 2 days, and (iv) a single dose of 400 mg mebendazole. Cure rates and egg reduction rates were assessed, and adverse events were monitored after treatments. Uncured patients accepted the second treatment with the same drugs after the first treatment. RESULTS: 156 patients were eligible for the study. Results from the first treatment showed that the cure rates of single-dose tribendimidine and praziquantel against C. sinensis were 50% and 56.8%, respectively; the single-dose tribendimidine achieved the cure rate of 77.8% in the treatment for hookworm, which was significantly higher than that of praziquantel; Low cure rates were obtained in the treatment of single-dose tribendimidine against Ascaris lumbricoides and Trichuris trichiura (28.6% and 23.1%). Results of the second treatment illustrated the cure rates of tribendimidine and praziquantel against C. sinensis were 78.1% and 75%, respectively. Most adverse events were mild and transient. Adverse events caused by tribendimidine were significantly less than praziquantel. CONCLUSION: Single-dose tribendimidine showed similar efficacy against C. sinensis as praziquantel with less adverse events, and achieved significantly higher cure rate in the treatment for hookworm than those of praziquantel and mebendazole. Low cure rates, which were still higher than other drugs, were obtained in the treatment of single-dose tribendimidine against Ascaris lumbricoides and Trichuris trichiura. TRIAL REGISTRATION: Controlled-Trials.com ISRCTN55086560.


Assuntos
Anti-Helmínticos/uso terapêutico , Clonorquíase/tratamento farmacológico , Coinfecção/tratamento farmacológico , Helmintíase/tratamento farmacológico , Mebendazol/uso terapêutico , Fenilenodiaminas/uso terapêutico , Praziquantel/uso terapêutico , Adulto , Animais , Ascaríase/tratamento farmacológico , Feminino , Humanos , Masculino , Mebendazol/efeitos adversos , Pessoa de Meia-Idade , Fenilenodiaminas/efeitos adversos , Praziquantel/efeitos adversos
12.
Parasitol Res ; 113(9): 3259-66, 2014 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24948106

RESUMO

The in vitro and in vivo efficacies of ozonide carboxylic acid OZ418 against Schistosoma japonicum were investigated. For in vitro experiments, juvenile (14-day-old) and adult schistosomes were collected from mice infected with 80-100 S. japonicum cercariae for 14 and 35 days post-infection and the worms were maintained in Roswell Park Memorial Institute (RPMI) 1640 supplemented by 10% calf serum. Against 35-day-old adult S. japonicum, OZ418 resulted in weakened worm motor activity, injury to the worm body, emergence of vacuoles along the worm surface, and death. A similar outcome was seen in 14-day-old juvenile S. japonicum exposed to OZ418. Ineffective concentrations (1, 5, and 10 µg/mL) of OZ418 also interacted with hemin to significantly increase the killing effect against adult schistosomes. The LC50 value of OZ418 against juvenile (14-day-old) and adult schistosomes were identical--16.2 µg/mL, whereas the corresponding LC95 values were 30.7 and 22.7 µg/mL, respectively. Treatment of adult and juvenile (14-day-old) S. japonicum-infected mice with single 200-400-mg/kg oral doses of OZ418 produced total worm burden reductions of 68.5-84.1 and 37.5-50.9%, respectively. Further study showed that in mice infected with various stages of schistosomes and treated with a single oral OZ418 400 mg/kg, poor efficacy was seen in the 3-h-old juvenile worm group, while 14-day-old and 21-day-old juvenile worm groups exhibited less efficacy with total worm burden reductions of 42.6-52.4%. On the other hand, similar and higher total worm burden reductions (64.2-76.0%) were seen in the 7-day-old juvenile worm group and 28-day-old as well as 35-day-old adult worm groups. Furthermore, the mean worm burden reductions of the 7-day-old juvenile worm group and 35-day-old adult worm group were statistically significantly higher than that of the 14-day-old or 21-day-old juvenile worm group (P < 0.01 or <0.05). These data suggest that OZ418 has promising efficacy against 7-day-old juvenile and adult S. japonicum.


Assuntos
Compostos Heterocíclicos com 1 Anel/uso terapêutico , Schistosoma japonicum , Esquistossomose Japônica/tratamento farmacológico , Esquistossomicidas/uso terapêutico , Compostos de Espiro/uso terapêutico , Administração Oral , Animais , Feminino , Compostos Heterocíclicos com 1 Anel/administração & dosagem , Compostos Heterocíclicos com 1 Anel/química , Dose Letal Mediana , Camundongos , Estrutura Molecular , Esquistossomicidas/administração & dosagem , Esquistossomicidas/química , Compostos de Espiro/administração & dosagem , Compostos de Espiro/química
13.
Acta Trop ; 131: 71-8, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24361723

RESUMO

In order to explore the interaction of mefloquine with hemin against adult Schistosoma japonicum in vitro, the 50% and 95% lethal concentration (LC50 and LC95) of mefloquine and hemin against schistosomes, some factors, such as other iron providing agents, iron chelaters, zinc protoporphyrin-IX, and biological relevant reductants, that might impact on antischistosomal activity induced by interaction of mefloquine with hemin, and preliminary analysis of chemical interaction of both compounds were undertaken. The LC50 and LC95 of mefloquine and hemin alone against schistosomes were determined to be 6.5µg/ml and 7.8µg/ml as well as 232µg/ml and 355µg/ml, respectively. The LC50 and LC95 of mefloquine in the presence of hemin 100µg/ml was 0.24µg/ml and 0.59µg/ml, respectively. On the other hand the LC50 and LC95 of hemin in the presence of mefloquine 1µg/ml was 23.2µg/ml and 77.2µg/ml, respectively. Meanwhile, mefloquine/hemin combinations showed potential synergistic effects against adult S. japonicum, with combination index (CI) values <1. Apart from hemin, zinc protoporphyrin-IX, and other iron providing agents such as ferrous sulfate and ferriammonium sulfate combined with mefloquine exhibited no toxic effect against schistosomes. On the other hand, addition of iron chelators (deferiprone, desferrioxamine mesylate, or 2,2'-bipyridine) to the medium containing mefloquine-hemin resulted in no protective effect on the worms. Furthermore, biological reductants like glutathione, vitamine C or cysteine showed no apparent worm protection effect from toxic mefloquine-hemin even at higher concentrations (242.3-614.6µg/ml, i.e., 6.4-17.8-fold higher than the concentration of hemin). Chemical interaction of mefloquine with hemin was studied in 40% DMSO-Tris buffer solution. Both UV-Vis spectrum and mass spectrum demonstrated the strong interaction of mefloquine with hemin, which resulted in a reduction of hemin color and emergence of an adduct formed by mefloquine and hemin. The results confirm that mefloquine combined with hemin exhibits potential synergistic effect against adult S. japonicum in vitro.


Assuntos
Anti-Helmínticos/farmacologia , Hemina/farmacologia , Mefloquina/farmacologia , Schistosoma japonicum/efeitos dos fármacos , 2,2'-Dipiridil/farmacologia , Animais , Ácido Ascórbico/farmacologia , Cisteína/farmacologia , Deferiprona , Desferroxamina/farmacologia , Sinergismo Farmacológico , Quimioterapia Combinada , Compostos Férricos/farmacologia , Compostos Ferrosos/farmacologia , Glutationa/farmacologia , Concentração Inibidora 50 , Quelantes de Ferro/farmacologia , Protoporfirinas , Piridonas/farmacologia , Schistosoma japonicum/crescimento & desenvolvimento
14.
Parasitol Res ; 112(11): 3723-40, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23979493

RESUMO

Up to date, schistosomiasis is still prevalent worldwide. It is estimated that more than 200 million individuals are infected, and 120 million suffer from clinical morbidity. Facing such huge cases of schistosomiasis, only heavy reliance on a single praziquantel for schistosomiasis control does not adapt and may promote the selection and spread of drug-resistant parasites. Therefore, it is an urgent need to develop the new antischistosomal drug. In 2008-2009, the antimalarial drug mefloquine, an arylaminoalcohol compound, has been found to be effective against schistosomes. According to the experimental studies, the deepest impression on the antischistosomal properties of mefloquine can be summarized as following points: (1) single dose of mefloquine possesses potential effect against three major species of schistosomes (Schistosoma mansoni, Schistosoma haematobium, and Schistosoma japonicum) infecting humans; (2) the drug displays similar effects against developing stages of juvenile and adult schistosomes, which are superior to that of artemisinins and praziquantel; (3) in vitro mefloquine exerts direct killing effect on juvenile and adult schistosomes, while in vivo, the efficacy of the drug is independent to host immune response, (4) mefloquine causes extensive and severe morphological, histopathological, and ultrastructural damage to adult and juvenile schistosomes, particularly, the worm tegument, musculature, gut, and vitelline glands of female worms are the key sites attacked by the drug; (5) combined treatment with mefloquine and praziquantel, or artemisinins shows synergistic effect against schistosome in experimental therapy,while in initially clinical trial, mefloquine in combination with artesunate also exhibits higher cure rates against schistosomiasis hematobia and schistosomiasis mansoni, and (6) several mefloquine-related arylmethanols exhibit potential effect against schistosomes in vivo, which is a useful clue helpful for development of new antischistosomal compound. In the present review, we have summarized the major results published in recent years, and the significance as well as the prospect for the future study of mefloquine have been discussed briefly.


Assuntos
Anti-Helmínticos/farmacologia , Mefloquina/farmacologia , Schistosoma haematobium/efeitos dos fármacos , Schistosoma japonicum/efeitos dos fármacos , Schistosoma mansoni/efeitos dos fármacos , Animais , Sinergismo Farmacológico , Humanos
15.
Acta Trop ; 126(2): 115-26, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23352956

RESUMO

The anthelminthic drug tribendimidine has been approved by Chinese authorities for human use in 2004, and a first comprehensive review was published in Acta Tropica in 2005. Here, we summarise further advances made through additional clinical trials and laboratory investigations. Two phase IV trials have been conducted in the People's Republic of China, the first one enrolling 1292 adolescents and adults aged 15-70 years and the second one conducted with 899 children aged 4-14 years who were infected with one or multiple species of soil-transmitted helminths. Oral tribendimidine (single 400mg enteric-coated tablet given to adolescents/adults and 200mg to children) showed high cure rates against Ascaris lumbricoides (90.1-95.0%) and moderate-to-high cure rates against hookworm (82.0-88.4%). Another trial done in school-aged children using a rigorous diagnostic approach found a cure rate against hookworm of 76.5%. A single oral dose of tribendimidine showed only low cure rates against Trichuris trichiura (23.9-36.8%) confirming previous results. Tribendimidine administered to children infected with Enterobius vermicularis (two doses of 200mg each on consecutive days) resulted in a high cure rate (97.1%). Importantly, a series of randomised, exploratory trials revealed that tribendimidine shows interesting activity against the liver flukes Opisthorchis viverrini and Clonorchis sinensis, the tapeworm Taenia spp. and the threadworm Strongyloides stercoralis with respective cure rates of 70.0%, 40.0%, 53.3% and 36.4%. Pharmacokinetic studies in healthy Chinese volunteers indicated that after oral administration of tribendimidine, no parent drug was detected in plasma, but its primary metabolite, p-(1-dimethylamino ethylimino) aniline (aminoamidine, deacylated amidantel) (dADT), was found in plasma. dADT is then further metabolised to acetylated dADT (AdADT). dADT exhibits activity against several species of hookworm and C. sinensis in experimental studies, similar to that of tribendimidine. First studies elucidating the mechanism of action suggested that tribendimidine is an L-type nicotinic acetylcholine receptor agonist. Additional experimental studies revealed that the anti-parasite spectrum of tribendimidine is very broad. Indeed, to date, activity has been documented against 20 different nematode, trematode and cestode species. Taken together, tribendimidine warrants further scientific inquiry, including more comprehensive toxicity appraisals, mechanism of action studies and clinical investigation as it holds promise as a broad spectrum anthelminthics.


Assuntos
Anti-Helmínticos/uso terapêutico , Helmintíase/tratamento farmacológico , Helmintos/efeitos dos fármacos , Fenilenodiaminas/uso terapêutico , Animais , Anti-Helmínticos/química , Anti-Helmínticos/farmacocinética , China , Humanos , Fenilenodiaminas/química , Fenilenodiaminas/farmacocinética
16.
Artigo em Chinês | MEDLINE | ID: mdl-24809183

RESUMO

OBJECTIVE: To explore whether mefloquine possesses the effect on granuloma formation induced by Schistosoma japonicum eggs. METHODS: Seventeen out of twenty-eight mice infected with 20 S. japonicum cercariae for 35 days were treated orally with mefloquine at a single dose of 200 mg/kg, and groups of 2-3 mice were sacrificed at various intervals post-treatment. The livers removed from each group of mice were fixed in 10% formaldehyde. While the remained 11 untreated mice divided into 6 groups (1-2 mice per group) were sacrificed at the same time periods as groups of mice treated with mefloquine, and their livers served as untreated corresponding controls. The granulomas with single egg in the center were counted and their diameters were measured using an ocular micrometer. The liver tissue sections were stained with hematoxylin and eosin (HE), Foot's or Mallory's methods for observation on histopathological alteration of egg granulomas, and on the appearance of reticular and collagen fibers within the granulomas. RESULTS: After infected mice were treated with mefloquine for 3, 7, 14, 21, 28 and 35 days, i.e., 38, 42, 49, 56, 63, and 70 days post-infection, the mean diameters of granuloma with single egg measured in the liver tissues section were (161 +/- 19), (175 +/- 13), (195 +/- 9), (171 +/- 40), (180 +/- 13), and (145 +/- 25) microm, respectively, and each of them was significantly lower than that of its corresponding control group of (189 +/- 18), (197 +/- 11), (211 +/- 12), (208 +/- 19), (203 +/- 16), and (207 +/- 36) microm (P < 0.01 or P < 0.05). Histopathological observation showed that in mice treated with mefloquine, the eosinophil-predominant inflammatory cells around the egg granuloma were sustained to 14-21 d post treatment (49-56 d post infection), which was significantly different from the corresponding control groups that all the eggs were surrounded by fibroblasts at 42 d post infection. Up to 28-35 d post treatment (63-70 d post infection), the boundary of egg granulomas distributed in the liver tissues of mefloquine treated groups was nearer in comparison to the corresponding control groups. Further observation on the reticular and collagen fibers within the egg granulomas by using specially staining methods demonstrated that in groups of mice treated with mefloquine for 2 weeks, the emergence and amount of the two kinds of fibers were delayed and less in comparison with corresponding control groups. After infected mice treated with mefloquine for 21 d (56 d post infection), the amount of the two kinds of fibers revealed in some egg granulomas was similar to the corresponding control group, but no further increase in the amount of the fibers, and seldom spread over the boundary of egg granuloma were seen 28 d and 35 d after treatment (63 d and 60 d post infection). While in corresponding control groups, the two kinds of fibers increased continuously with time post infection to become thick, and spread over the boundary of granuloma to further interconnect with the fibers stretched from the adjacent granuloma, and separate the liver tissue to form the grid-like structure. CONCLUSION: Preliminary observation demonstrates that mefloquine possesses suppressive effect on granuloma formation induced by S. japonicum eggs.


Assuntos
Granuloma/patologia , Fígado/parasitologia , Mefloquina/uso terapêutico , Esquistossomose Japônica/patologia , Animais , Feminino , Granuloma/etiologia , Fígado/patologia , Camundongos , Camundongos Endogâmicos , Óvulo , Schistosoma japonicum/efeitos dos fármacos , Esquistossomose Japônica/tratamento farmacológico
17.
Artigo em Chinês | MEDLINE | ID: mdl-24812850

RESUMO

OBJECTIVE: To observe and compare the inhibition of hemozoin formation and the in vitro as well as in vivo antischistosomal activity induced by seven antimalarial drugs. METHODS: Inhibition of hemozoin formation displayed by chloroquine phosphate, quinine hydrochloride, quinidine, mefloquine hydrochloride, pyronaridine phosphate and lumefantrine at 25 micromol/L, and artemether at 100 micromol/L was performed by assay of inhibition of beta-hematin formation in 1 mol/L sodium acetate buffers containing hematin with various pH of 4.0, 4.2, 4.4, 4.6, 4.8, and 5.0. In in vitro antischistosomal study, the medium of RPMI 1640 supplemented by 10% calf serum was used to maintain the adult Schistosoma japonicum, and the 50% and 95% lethal concentrations (LC50 and LC95) to kill the adult worms of each drug were then determined. Meanwhile, the interaction of quinine, pyronaridine and chloroquine combined with hemin against adult schistosomes was also undertaken. As to in vivo test, the efficacy of seven antimalarial drugs administered orally or intraperitoneally to mice infected with adult schistosomes was observed. RESULTS: In the acidic acetate-hematin solution, 25 micromol/L pyronaridine showed significant inhibition of beta-hematin formation at pH 4.4-5.0 with inhibition rates of 81.3%-97.0%. At pH 4.6, the inhibition rates of beta-hematin formation in acetate-hematin solution induced by mefloquine, chloroquine or quinine at concentration of 25 beta mol/L were 79.7%, 72.8% or 65.8%, respectively, and the beta-hematin formation was continually inhibited by these 3 antimalarial drugs at pH 4.8 and 5.0 with inhibition rates of 83.1%-90.6%, 41.9%-49.0% or 53.2-62.0%. The inhibition rates of beta-hematin formation at pH 4.6 and 4.8-5.0 induced by lumefantrine 25 micromol/L were 74.3% and 40.4%-40.5%, respectively. While under the same concentration of quinidine, 53.4% and 50.9% inhibition rates of beta-hematin formation were observed at pH 4.8 and 5.0. As to artemether, higher concentration of 100 micromol/L only showed light inhibition of beta-hematin formation at pH 4.4-4.8 with inhibition rates of 16.6%-25.0%. As regard to in vitro test, the LC50 and LC95 of mefloquine, pyronaridine, quinine and quinidine were 4.93 and 6.123 microg/ml, 37.278 and 75.703 microg/ml, 93.688 and 134.578 microg/ml, as well as 101.534 and 129.957 microg/ml, respectively. When adult schistosomes were exposed to the medium containing chloroquine, lumefantrine or artemether at higher concentrations of 100 or 120 microg/ml for 72 h, no or only individual worms died. Hence the LC50 and LC95 of these 3 drugs could not be determined. In other in vitro test, adult schistosomes exposed to quinine 50 micromol/L (20 microg/ml) in combination with 153.4 micromol/L (100 microg/ml) hemin, all worms died within 72 h post incubation. While the worms exposed to 50 micromol/L (26 microg/ml) chloroquine combined with the same concentration of hemin, only 18.8%(3/16) of worm died at 72 h post exposure. Unexpectedly, in schistosomes exposed to pyronaridine at a toxic concentrations of 50 micromol/L (46 microg/ml) in combination with 153.4 mol/L (100 microg/ml) hemin for 72 h, all of the worms were protected from the toxic action induced by pyronaridine, which revealed in normal motor activity and appearance of morphology in majority of the worms. In in vivo test, mice infected with adult schistosomes were treated orally with chloroquine, pyronaridine or lumefantrine at a daily dose of 400 mg/kg for 3 days, or intraperitoneally with chloroquine or pyronaridine at a daily dose of 100 mg/kg for 2 or 3 days, no apparent efficacy was seen. When mefloquine, quinine, quinidine or artemether were administered orally to infected mice at a single dose of 400 mg/kg or 200 mg/kg (mefloquine), all groups of mice treated showed moderate or higher efficacy with worm burden reductions of 61.1%-98.1%. CONCLUSION: Among the seven antimalarial drugs tested, their inhibitions of hemozoin (beta-hematin) exhibit no definite correlation to their in vitro and in vivo antischistosomal activity. Quinine in combination with hemin shows synergistic effect against schistosomes in vitro. While antagonist effect is observed in pyronaridine combined with hemin.


Assuntos
Antimaláricos/farmacologia , Hemeproteínas/metabolismo , Schistosoma japonicum/efeitos dos fármacos , Animais , Antimaláricos/classificação , Camundongos
18.
Artigo em Inglês | MEDLINE | ID: mdl-24818405

RESUMO

OBJECTIVE: To observe the ultrastructural alterations of adult Schistosoma japonicum induced by synthetic trioxolane OZ78. METHODS: Eight out of ten mice infected with 40-60 S. japonicum cercariae for 35 d were treated orally with OZ78 at a single dose of 400 mg/kg. Four groups of two mice were killed at 24 h, 3 d, 7 d, and 14 d post treatment, and schistosomes were recovered by perfusion technique, fixed, and examined by transmission electron microscopy. Schistosomes obtained from the remaining two untreated mice served as control. RESULTS: After infected mice were treated with OZ78 for 24 h, the prominent alterations in tegument of both male and female worms were observed, which revealed in flattened surface due to swelling of cytoplasmic processes, irregular expansion in distal end of cytoplasmic processes accompanied by decrease in rod-like and discoid-like secretory bodies, focal lysis of tegumental matrix; fusion of some cytoplasmic processes to form a large piece, disruption or disappearance of basal membrane, and destruction of internal structures in sensory organelles. In the subtegument, no or slight swelling and focal lysis of muscle bundles were seen, while the syncytium beneath the muscle showed enlargement of nucleus with indistinction of partial nuclear membrane, formation of small vacuoles due to focal lysis of chromatin, and emergence of degenerated mitochondria in perinuclear cytoplasm. As to parenchymal tissues, the major alterations included degeneration of mitochondria, formation of some small vacuoles and myelin-like structures. In gut epithelial cells, the prominent alterations were irregular enlargement of nucleus with light lysis of nucleoli and fusion of partial bi-layer nuclear membrane, degeneration of mitochondria in cytoplasm and collapse of microvilli. At this time point, in the vitelline cells of female worms, the most significant alteration was the collapse of many vitelline droplets, which led to release of the vitelline balls, followed by their lysis and fusion. Three to 7 d post treatment, the damage to the worms aggravated either in extent or in severity along with time. The significant damages to male and female worms were fusion of cytoplasmic processes, peeling or collapse of damaged cytoplasmic processes resulting in exposure of muscle bundles, severe destruction of sensory organelles and syncytium, focal or extensive swelling and lysis of muscle bundles, emergence of some larger piece of degenerated parenchymal tissues and severe damage to the gut epithelial cell. While in the vitelline cells of female worms, decrease in the number of vitelline droplet, focal lysis of nucleus and extensive lysis of parenchymal tissues among the vitelline cells were also observed. Fourteen days post OZ78 dosing, male and female worms which survived the treatment showed some renovation in damaged tegument and subtegument, while most gut epithelial cells and vitelline cells still revealed in prominent injury. CONCLUSION: The results demonstrate that OZ78 possesses an extensive damage to the ultrastructure in tegument and subtegument tissues including syncytium, parenchymal tissues, gut epithelial cells, and vitelline cells of adult S. japonicum.


Assuntos
Adamantano/análogos & derivados , Schistosoma japonicum/ultraestrutura , Esquistossomose Japônica/parasitologia , Esquistossomicidas/farmacologia , Adamantano/farmacologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos , Schistosoma japonicum/efeitos dos fármacos , Esquistossomose Japônica/tratamento farmacológico
19.
Artigo em Chinês | MEDLINE | ID: mdl-22908816

RESUMO

In recent years, antimalarial drug mefloquine, an amino alcohol compound, has been found to exhibit potential effect against schistosomes. The feature of antischistosomal properties of mefloquine is that the drug possesses similar killing effect against various development stages of juvenile and adult schistosomes. This paper summarizes the recent three years' progress in experimental studies of mefloquine against schistosomes and other helminthes.


Assuntos
Anti-Helmínticos/farmacologia , Helmintos/efeitos dos fármacos , Mefloquina/farmacologia , Schistosoma/efeitos dos fármacos , Animais
20.
Zhongguo Zhen Jiu ; 32(3): 261-3, 2012 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-22471146

RESUMO

The concept of needle-acupointomics should be clarified initially in order to discuss the relative researches. The comprehension can be deepened through the aspects of researching methods, content and goals. Proper researching model and analysis method should be selected so as to bring the advantages of the ancient acupuncture literatures, case records and clinical experiences of famous physicians into full play. Only in this way can the domestic needle acupointomics studies achieve a breakthrough.


Assuntos
Pontos de Acupuntura , Terapia por Acupuntura , Pesquisa Biomédica , Terapia por Acupuntura/instrumentação , Terapia por Acupuntura/métodos , Animais , Humanos , Agulhas
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