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1.
Arch Microbiol ; 206(4): 134, 2024 Mar 04.
Artigo em Inglês | MEDLINE | ID: mdl-38433145

RESUMO

Acanthamoeba castellanii are opportunistic pathogens known to cause infection of the central nervous system termed: granulomatous amoebic encephalitis, that mostly effects immunocompromised individuals, and a sight threatening keratitis, known as Acanthamoeba keratitis, which mostly affects contact lens wearers. The current treatment available is problematic, and is toxic. Herein, an amphiphilic star polymer with AB2 miktoarms [A = hydrophobic poly(ℇ-Caprolacton) and B = hydrophilic poly (ethylene glycol)] was synthesized by ring opening polymerization and CuI catalyzed azide-alkyne cycloaddition. Characterization by 1H and 13C NMR spectroscopy, size-exclusion chromatography and fluorescence spectroscopy was accomplished. The hydrophobic drug itraconazole (ITZ) was incorporated in self-assembled micellar structure of AB2 miktoarms through co-solvent evaporation. The properties of ITZ loaded (ITZ-PCL-PEG2) and blank micelles (PCL-PEG2) were investigated through zeta sizer, scanning electron microscopy and Fourier-transform infrared spectroscopy. Itraconazole alone (ITZ), polymer (DPB-PCL), empty polymeric micelles (PCL-PEG2) alone, and itraconazole loaded in polymeric micelles (ITZ-PCL-PEG2) were tested for anti-amoebic potential against Acanthamoeba, and the cytotoxicity on human cells were determined. The polymer was able to self-assemble in aqueous conditions and exhibited low value for critical micelle concentration (CMC) 0.05-0.06 µg/mL. The maximum entrapment efficiency of ITZ was 68%. Of note, ITZ, DPB, PCL-PEG2 and ITZ-PCL-PEG2 inhibited amoebae trophozoites by 37.34%, 36.30%, 35.77%, and 68.24%, respectively, as compared to controls. Moreover, ITZ-PCL-PEG2 revealed limited cytotoxicity against human keratinocyte cells. These results are indicative that ITZ-PCL-PEG2 micelle show significantly better anti-amoebic effects as compared to ITZ alone and thus should be investigated further in vivo to determine its clinical potential.


Assuntos
Acanthamoeba castellanii , Micelas , Humanos , Itraconazol/farmacologia , Alcinos , Polímeros
2.
Horm Metab Res ; 54(8): 562-566, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35724687

RESUMO

In the aftermath of the corona pandemic, long-COVID or post-acute COVID-19 syndrome still represents a great challenge, and this topic will continue to represent a significant health problem in the coming years. At present, the impact of long-COVID on our health system cannot be fully assessed but according to current studies, up to 40% of people who have been infected with SARS-CoV-2 suffer from clinically relevant symptoms of long-COVID syndrome several weeks to months after the acute phase. The main symptoms are chronic fatigue, dyspnea, and various cognitive symptoms. Initial studies have shown that people with overweight and diabetes mellitus have a higher risk of developing long-COVID associated symptoms. Furthermore, repeated treatment of acute COVID-19 and long-COVID with steroids can contribute to long-term metabolic and endocrine disorders. Therefore, a structured program with rehabilitation and physical activity as well as optimal dietary management is of utmost importance, especially for patients with metabolic diseases and/or long-COVID. Furthermore, the removal of autoantibodies and specific therapeutic apheresis procedures could lead to a significant improvement in the symptoms of long-COVID in individual patients.


Assuntos
COVID-19 , Doenças do Sistema Endócrino , COVID-19/complicações , Doenças do Sistema Endócrino/complicações , Doenças do Sistema Endócrino/epidemiologia , Doenças do Sistema Endócrino/terapia , Humanos , Pandemias , SARS-CoV-2 , Síndrome de COVID-19 Pós-Aguda
3.
Traffic ; 18(11): 733-746, 2017 11.
Artigo em Inglês | MEDLINE | ID: mdl-28799243

RESUMO

Eukaryotic cells utilize multiple endocytic pathways for specific uptake of ligands or molecules, and these pathways are commonly hijacked by pathogens to enable host cell invasion. Escherichia coli K1, a pathogenic bacterium that causes neonatal meningitis, invades the endothelium of the blood-brain barrier, but the entry route remains unclear. Here, we demonstrate that the bacteria trigger an actin-mediated uptake route, stimulating fluid phase uptake, membrane ruffling and macropinocytosis. The route of uptake requires intact lipid rafts as shown by cholesterol depletion. Using a variety of perturbants we demonstrate that small Rho GTPases and their downstream effectors have a significant effect on bacterial invasion. Furthermore, clathrin-mediated endocytosis appears to play an indirect role in E. coli K1 uptake. The data suggest that the bacteria effect a complex interplay between the Rho GTPases to increase their chances of uptake by macropinocytosis into human brain microvascular endothelial cells.


Assuntos
Encéfalo/microbiologia , Células Endoteliais/microbiologia , Escherichia coli/patogenicidade , Microvasos/microbiologia , Pinocitose/fisiologia , Actinas/metabolismo , Translocação Bacteriana , Encéfalo/irrigação sanguínea , Linhagem Celular , Colesterol/metabolismo , Células Endoteliais/metabolismo , Endotélio Vascular/metabolismo , Endotélio Vascular/microbiologia , Escherichia coli/fisiologia , Humanos , Microvasos/metabolismo , Virulência
4.
Anticancer Drugs ; 28(1): 75-87, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27606721

RESUMO

Recent reports on acetylcholine muscarinic receptor subtype 3 (CHRM3) have shown its growth-promoting role in prostate cancer. Additional studies report the proliferative effect of the cholinergic agonist carbachol on prostate cancer by its agonistic action on CHRM3. This study shows that the type 1 acetylcholine muscarinic receptor (CHRM1) contributes toward the proliferation and growth of prostate cancer. We used growth and cytotoxic assays, the prostate cancer microarray database and CHRM downstream pathways' homology of CHRM subtypes to uncover multiple signals leading to the growth of prostate cancer. Growth assays showed that pilocarpine stimulates the proliferation of prostate cancer. Moreover, it shows that carbachol exerts an additional agonistic action on nicotinic cholinergic receptor of prostate cancer cells that can be blocked by tubocurarine. With the use of selective CHRM1 antagonists such as pirenzepine and dicyclomine, a considerable inhibition of proliferation of prostate cancer cell lines was observed in dose ranging from 15-60 µg/ml of dicyclomine. The microarray database of prostate cancer shows a dominant expression of CHRM1 in prostate cancer compared with other cholinergic subtypes. The bioinformatics of prostate cancer and CHRM pathways show that the downstream signalling include PIP3-AKT-CaM-mediated growth in LNCaP and PC3 cells. Our study suggests that antagonism of CHRM1 may be a potential therapeutic target against prostate cancer.


Assuntos
Neoplasias da Próstata/metabolismo , Receptor Muscarínico M1/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/fisiologia , Diciclomina/farmacologia , Humanos , Masculino , Pirenzepina/farmacologia , Neoplasias da Próstata/tratamento farmacológico , Neoplasias da Próstata/genética , Neoplasias da Próstata/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor Muscarínico M1/antagonistas & inibidores , Receptor Muscarínico M1/biossíntese , Receptor Muscarínico M1/genética , Receptor Muscarínico M3/biossíntese , Receptor Muscarínico M3/genética , Receptor Muscarínico M3/metabolismo , Receptores Androgênicos/metabolismo , Transdução de Sinais
5.
J Basic Microbiol ; 57(7): 574-579, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28466971

RESUMO

Here we describe features of apoptosis in unicellular Acanthamoeba castellanii belonging to the T4 genotype. When exposed to apoptosis-inducing compounds such as doxorubicin, A. castellanii trophozoites exhibited cell shrinkage and membrane blebbing as observed microscopically, DNA fragmentation using agarose gel electrophoresis, and phosphatidylserine (PS) externalization using annexin V immunostaining. Overall, these findings suggest the existence of apoptosis in A. castellanii possibly mediated by intrinsic apoptotic cascade. Further research in this field could provide avenues to selectively induce apoptosis in A. castellanii by triggering intrinsic apoptotic cascade.


Assuntos
Acanthamoeba castellanii/citologia , Acanthamoeba castellanii/fisiologia , Apoptose , Acanthamoeba castellanii/efeitos dos fármacos , Acanthamoeba castellanii/genética , Animais , Anexina A5/análise , Fragmentação do DNA , Doxorrubicina/farmacologia , Genótipo , Trofozoítos/efeitos dos fármacos
7.
Eur J Med Chem ; 271: 116440, 2024 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-38678825

RESUMO

Antimicrobial and chemotherapy resistance are escalating medical problem of paramount importance. Yet, research for novel antimicrobial and anticancer agents remains lagging behind. With their reported medical applications, DNA minor groove binders (MGBs) are worthy of exploration. In this study, the approach of structure-based drug design was implemented to generate 11 MGB compounds including a novel class of bioactive alkyne-linked MGBs. The NCI screening protocol was utilized to evaluate the antitumor activity of the target MGBs. Furthermore, a variety of bactericidal, cytopathogenicity, MIC90, and cytotoxicity assays were carried out using these MGBs against 6 medically relevant bacteria: Salmonella enterica, Escherichia coli, Serratia marcescens, Bacillus cereus, Streptococcus pneumoniae and Streptococcus pyogenes. Moreover, molecular docking, molecular dynamic simulations, DNA melting, and isothermal titration calorimetry (ITC) analyses were utilized to explore the binding mode and interactions between the most potent MGBs and the DNA duplex d(CGACTAGTCG)2. NCI results showed that alkyne-linked MGBs (26 & 28) displayed the most significant growth inhibition among the NCI-60 panel. In addition, compounds MGB3, MGB4, MGB28, and MGB32 showed significant bactericidal effects, inhibited B. cereus and S. enterica-mediated cytopathogenicity, and exhibited low cytotoxicity. MGB28 and MGB32 demonstrated significant inhibition of S. pyogenes, whereas MGB28 notably inhibited S. marcescens and all four minor groove binders significantly inhibited B. cereus. The ability of these compounds to bind with DNA and distort its groove dimensions provides the molecular basis for the allosteric perturbation of proteins-DNA interactions by MGBs. This study shed light on the mechanism of action of MGBs and revealed the important structural features for their antitumor and antibacterial activities, which are important to guide future development of MGB derivatives as novel antibacterial and anticancer agents.


Assuntos
Antibacterianos , Antineoplásicos , DNA , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Antineoplásicos/farmacologia , Antineoplásicos/química , Antineoplásicos/síntese química , Humanos , Relação Estrutura-Atividade , DNA/química , DNA/metabolismo , Estrutura Molecular , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Linhagem Celular Tumoral , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular
8.
Heliyon ; 10(1): e23592, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38187258

RESUMO

Microgravity, in space travel and prolonged bed rest conditions, induces cardiovascular deconditioning along with skeletal muscle mass loss and weakness. The findings of microgravity research may also aid in the understanding and treatment of human health conditions on Earth such as muscle atrophy, and cardiovascular diseases. Due to the paucity of biomarkers and the unknown underlying mechanisms of cardiovascular and skeletal muscle deconditioning in these environments, there are insufficient diagnostic and preventative measures. In this study, we employed hindlimb unloading (HU) mouse model, which mimics astronauts in space and bedridden patients, to first evaluate cardiovascular and skeletal muscle function, followed by proteomics and metabolomics LC-MS/MS-based analysis using serum samples. Three weeks of unloading caused changes in the function of the cardiovascular system in c57/Bl6 mice, as seen by a decrease in mean arterial pressure and heart weight. Unloading for three weeks also changed skeletal muscle function, causing a loss in grip strength in HU mice and atrophy of skeletal muscle indicated by a reduction in muscle mass. These modifications were partially reversed by a two-week recovery period of reloading condition, emphasizing the significance of the recovery process. Proteomics analysis revealed 12 dysregulated proteins among the groups, such as phospholipid transfer protein, Carbonic anhydrase 3, Parvalbumin alpha, Major urinary protein 20 (Mup20), Thrombospondin-1, and Apolipoprotein C-IV. On the other hand, metabolomics analysis showed altered metabolites among the groups such as inosine, hypoxanthine, xanthosine, sphinganine, l-valine, 3,4-Dihydroxyphenylglycol, and l-Glutamic acid. The joint data analysis revealed that HU conditions mainly impacted pathways such as ABC transporters, complement and coagulation cascades, nitrogen metabolism, and purine metabolism. Overall, our results indicate that microgravity environment induces significant alterations in the function, proteins, and metabolites of these mice. These observations suggest the potential utilization of these proteins and metabolites as novel biomarkers for assessing and mitigating cardiovascular and skeletal muscle deconditioning associated with such conditions.

9.
Exp Parasitol ; 132(3): 367-72, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22960347

RESUMO

Acanthamoeba granulomatous encephalitis (AGE), caused by Acanthamoeba castellanii, is a fatal infection of immunocompromised individuals. The pathogenesis of blood-brain barrier (BBB) breach remains unknown. Using a novel in vitro BBB infection model under flow conditions, demonstrates that increases in flow rates lead to decreased binding of A. castellanii to host cells. This is a distinct departure from previous findings under static conditions. However, similarly to static conditions binding of A. castellanii to host cells is host mannose dependent. Disruption of the host cell monolayer was independent of amoeba binding, but dependent on secreted serine proteases. For the first time we report the binding dynamics of A. castellanii under physiological conditions, showing that BBB disruption is not directly linked to binding, instead it is reliant on secreted proteases. Our results offer a platform on which therapies designed at modulating physiological parameters can improve the outcome of infection with A. castellanii.


Assuntos
Acanthamoeba castellanii/fisiologia , Amebíase/parasitologia , Barreira Hematoencefálica/parasitologia , Encefalite/parasitologia , Serina Proteases/metabolismo , Encéfalo/citologia , Encéfalo/parasitologia , Células Cultivadas , Meios de Cultivo Condicionados , Células Endoteliais/parasitologia , Endotélio Vascular/citologia , Endotélio Vascular/parasitologia , Humanos , Hidrodinâmica , Lectina de Ligação a Manose/metabolismo , Microvasos/metabolismo , Microvasos/parasitologia
10.
Antibiotics (Basel) ; 11(7)2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35884189

RESUMO

The free-living amoeba Acanthamoeba castellanii is responsible for the central nervous infection granulomatous amoebic encephalitis and sight-threatening infection Acanthamoeba keratitis. Moreover, no effective treatment is currently present, and a combination drug therapy is used. In this study, twelve DNA minor groove binders (MGBs) were synthesized and tested for their antiamoebic activity via amoebicidal, encystation, excystation, and cytopathogenicity assays. It was found that the compounds MGB3, MGB6, MGB22, MGB24, and MGB16 significantly reduce amoeba viability to 76.20%, 59.45%, 66.5%, 39.32%, and 43.21%, respectively, in amoebicidal assays. Moreover, the compounds MGB6, MGB20, MGB22, MGB28, MGB30, MGB32, and MGB16 significantly inhibit Acanthamoeba cysts, leading to the development of only 46.3%, 39%, 30.3%, 29.6%, 27.8%, 41.5%, and 45.6% cysts. Additionally, the compounds MGB3, MGB4, MGB6, MGB22, MGB24, MGB28, MGB32, and MGB16 significantly reduce the re-emergence of cysts to trophozoites, with viable trophozoites being only 64.3%, 47.3%, 41.4%, 52.9%, 55.4%, 40.6%, 62.1%, and 51.7%. Moreover, the compounds MGB3, MGB4, and MGB6 exhibited the greatest reduction in amoeba-mediated host-cell death, with cell death reduced to 41.5%, 49.4%, and 49.5%. With the following determined, future in vivo studies can be carried out to understand the effect of the compounds on animal models such as mice.

11.
BMC Microbiol ; 10: 186, 2010 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-20615207

RESUMO

BACKGROUND: Many aspects of Acanthamoeba granulomatous encephalitis remain poorly understood, including host susceptibility and chronic colonization which represent important features of the spectrum of host-pathogen interactions. Previous studies have suggested locusts as a tractable model in which to study Acanthamoeba pathogenesis. Here we determined the mode of parasite invasion of the central nervous system (CNS). RESULTS: Using Acanthamoeba isolates belonging to the T1 and T4 genotypes, the findings revealed that amoebae induced sickness behaviour in locusts, as evidenced by reduced faecal output and weight loss and, eventually, leading to 100% mortality. Significant degenerative changes of various tissues were observed by histological sectioning. Both isolates produced disseminated infection, with viable amoebae being recovered from various tissues. Histological examination of the CNS showed that Acanthamoeba invaded the locust CNS, and this is associated with disruption of the perineurium cell/glial cell complex, which constitutes the locust blood-brain barrier. CONCLUSIONS: This is the first study to demonstrate that Acanthamoeba invades locust brain by modulating the integrity of the insect's blood-brain barrier, a finding that is consistent with the human infection. These observations support the idea that locusts provide a tractable model to study Acanthamoeba encephalitis in vivo. In this way the locust model may generate potentially useful leads that can be tested subsequently in mammalian systems, thus replacing the use of vertebrates at an early stage, and reducing the numbers of mammals required overall.


Assuntos
Acanthamoeba/fisiologia , Amebíase/parasitologia , Modelos Animais de Doenças , Gafanhotos , Acanthamoeba/genética , Animais , Barreira Hematoencefálica/parasitologia , Sistema Nervoso Central/parasitologia , Feminino , Genótipo , Gafanhotos/parasitologia , Humanos , Masculino
12.
Anticancer Agents Med Chem ; 20(13): 1558-1570, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32364082

RESUMO

BACKGROUND: Cancer contributes to significant morbidity and mortality despite advances in treatment and supportive care. There is a need for the identification of effective anticancer agents. Reptiles such as tortoise, python, and water monitor lizards are exposed to heavy metals, tolerate high levels of radiation, feed on rotten/germ-infested feed, thrive in unsanitary habitat and yet have prolonged lifespans. Such species are rarely reported to develop cancer, suggesting the presence of anticancer molecules/mechanisms. METHODS: Here, we tested effects from sera of Asian water monitor lizard (Varanus salvator), python (Malayopython reticulatus) and tortoise (Cuora kamaroma amboinensis) against cancer cells. Sera were collected and cytotoxicity assays were performed using prostate cancer cells (PC3), Henrietta Lacks cervical adenocarcinoma cells (HeLa) and human breast adenocarcinoma cells (MCF7), as well as human keratinized skin cells (Hacat), by measuring lactate dehydrogenase release as an indicator for cell death. Growth inhibition assays were performed to determine the effects on cancer cell proliferation. Liquid chromatography mass spectrometry was performed for molecular identification. RESULTS: The findings revealed that reptilian sera, but not bovine serum, abolished viability of Hela, PC3 and MCF7 cells. Samples were subjected to liquid chromatography mass spectrometry, which detected 57 molecules from V. salvator, 81 molecules from Malayopython reticulatus and 33 molecules from C. kamaroma amboinensis and putatively identified 9 molecules from V. salvator, 20 molecules from Malayopython reticulatus and 9 molecules from C. kamaroma amboinensis when matched against METLIN database. Based on peptide amino acid composition, binary profile, dipeptide composition and pseudo-amino acid composition, 123 potential Anticancer Peptides (ACPs) were identified from 883 peptides from V. salvator, 306 potential ACPs from 1074 peptides from Malayopython reticulatus and 235 potential ACPs from 885 peptides from C. kamaroma amboinensis. CONCLUSION: To our knowledge, for the first time, we reported comprehensive analyses of selected reptiles' sera using liquid chromatography mass spectrometry, leading to the identification of potentially novel anticancer agents. We hope that the discovery of molecules from these animals will pave the way for the rational development of new anticancer agents.


Assuntos
Peptídeos Catiônicos Antimicrobianos/farmacologia , Antineoplásicos/farmacologia , Animais , Peptídeos Catiônicos Antimicrobianos/sangue , Peptídeos Catiônicos Antimicrobianos/química , Antineoplásicos/sangue , Antineoplásicos/química , Boidae/sangue , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Lagartos/sangue , Estrutura Molecular , Relação Estrutura-Atividade , Tartarugas/sangue
13.
Med Chem ; 16(7): 841-847, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31544702

RESUMO

BACKGROUND: Acanthamoeba is an opportunistic pathogen widely spread in the environment. Acanthamoeba causes excruciating keratitis which can lead to blindness. The lack of effective drugs and its ability to form highly resistant cyst are one of the foremost limitations against successful prognosis. Current treatment involves mixture of drugs at high doses but still recurrence of infection can occur due to ineffectiveness of drugs against the cyst form. Pyridine and its natural and synthetic derivatives are potential chemotherapeutic agents due to their diverse biological activities. OBJECTIVE: To study the antiamoebic effects of four novel synthetic dihydropyridine (DHP) compounds against Acanthamoeba castellanii belonging to the T4 genotype. Furthermore, to evaluate their activity against amoeba-mediated host cells cytopathogenicity as well as their cytotoxicity against human cells. METHODS: Dihydropyridines were synthesized by cyclic dimerization of alkylidene malononitrile derivatives. Four analogues of functionally diverse DHPs were tested against Acanthamoeba castellanii by using amoebicidal, encystation and excystation assays. Moreover, Lactate dehydrogenase assays were carried out to study cytopathogenicity and cytotoxicity against human cells. RESULTS: These compounds showed significant amoebicidal and cysticidal effects at 50 µM concentration, whereas, two of the DHP derivatives also significantly reduced Acanthamoebamediated host cell cytotoxicity. Moreover, these DHPs were found to have low cytotoxicity against human cells suggesting a good safety profile. CONCLUSION: The results suggest that DHPs have potential against Acanthamoeba especially against the more resistant cyst stage and can be assessed further for drug development.


Assuntos
Acanthamoeba castellanii/efeitos dos fármacos , Antiprotozoários/farmacologia , Di-Hidropiridinas/farmacologia , Antiprotozoários/síntese química , Antiprotozoários/química , Sobrevivência Celular/efeitos dos fármacos , Di-Hidropiridinas/síntese química , Di-Hidropiridinas/química , Relação Dose-Resposta a Droga , Células HeLa , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
14.
Curr Pharm Biotechnol ; 21(5): 425-437, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31577204

RESUMO

BACKGROUND: Snakes feed on germ-infested rodents, while water monitor lizards thrive on rotten matter in unhygienic conditions. We hypothesize that such creatures survive the assault of superbugs and are able to fend off disease by producing antimicrobial substances. In this study, we investigated the potential antibacterial activity of sera/lysates of animals living in polluted environments. METHODS: Snake (Reticulatus malayanus), rats (Rattus rattus), water monitor lizard (Varanus salvator), frog (Lithobates catesbeianus), fish (Oreochromis mossambicus), chicken (Gallus gallus domesticus), and pigeon (Columba livia) were dissected and their organ lysates/sera were collected. Crude extracts were tested for bactericidal effects against neuropathogenic E. coli K1, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus pyogenes, Pseudomonas aeruginosa, Bacillus cereus and Klebsiella pneumoniae. To determine whether lysates/sera protect human cells against bacterialmediated damage, cytotoxicity assays were performed by measuring lactate dehydrogenase release as an indicator of cell death. Lysates/sera were partially characterized using heat-treatment and pronasetreatment and peptide sequences were determined using the Liquid Chromatography Mass Spectrometry (LC-MS). RESULTS: Snake and water monitor lizard sera exhibited potent broad-spectrum bactericidal effects against all bacteria tested. Heat inactivation and pronase-treatment inhibited bactericidal effects indicating that activity is heat-labile and pronase-sensitive suggesting that active molecules are proteinaceous in nature. LCMS analyses revealed the molecular identities of peptides. CONCLUSION: The results revealed that python that feeds on germ-infested rodents and water monitor lizards that feed on rotten organic waste possess antibacterial activity in a heat-sensitive manner and several peptides were identified. We hope that the discovery of antibacterial activity in the sera of animals living in polluted environments will stimulate research in finding antibacterial agents from unusual sources as this has the potential for the development of novel strategies in the control of infectious diseases.


Assuntos
Antibacterianos/farmacologia , Produtos Biológicos/farmacologia , Microbiologia Ambiental/normas , Soro/química , Extratos de Tecidos/farmacologia , Animais , Antibacterianos/isolamento & purificação , Produtos Biológicos/isolamento & purificação , Escherichia coli/efeitos dos fármacos , Humanos , Klebsiella pneumoniae/efeitos dos fármacos , Lagartos/sangue , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Ratos , Serpentes/sangue , Extratos de Tecidos/isolamento & purificação
15.
J Eukaryot Microbiol ; 56(2): 136-41, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-21462548

RESUMO

Here, we determined the staining properties of Balamuthia mandrillaris cysts, and assessed the effect of 2, 6-dichlorobenzonitrile (DCB), a cellulose synthesis inhibitor, and calcofluor white, a brightening agent, on its encystment. Periodic acid-Schiff reagent stained the inner wall intensely and middle and outer walls weakly suggesting that the cyst wall of B. mandrillaris may contain glycans. Furthermore, cysts, but not trophozoites, fluoresced when stained with calcofluor white. Calcofluor white and DCB, a cellulose synthesis inhibitor, inhibited B. mandrillaris encystment. This is the first report suggesting possible glycan biosynthesis in B. mandrillaris encystment, and this pathwaymay provide a potentially useful drug target and help improve treatment.


Assuntos
Benzenossulfonatos/farmacologia , Lobosea/efeitos dos fármacos , Nitrilas/farmacologia , Coloração e Rotulagem/métodos , Amebíase/tratamento farmacológico , Animais , Benzenossulfonatos/química , Encéfalo/parasitologia , Parede Celular/química , Parede Celular/ultraestrutura , Encefalite/tratamento farmacológico , Interações Hospedeiro-Parasita , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Lobosea/química , Lobosea/crescimento & desenvolvimento , Lobosea/ultraestrutura , Mandrillus/parasitologia , Nitrilas/química , Reação do Ácido Periódico de Schiff , Trofozoítos/efeitos dos fármacos
16.
Anticancer Agents Med Chem ; 19(18): 2251-2268, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31660845

RESUMO

BACKGROUND: Species of crocodiles and cockroaches can withstand high radiation, reside in unsanitary conditions, thrive on germ-infested feed, and are exposed to heavy metals, yet they are not reported to develop cancer. It has been postulated that such species have mechanisms to defend themselves against developing cancer. Here, selected species have been tested for potential cytotoxicity against selected cancer cell lines. METHODS: In this study, various species of vertebrates and invertebrates were procured including Columba livia, Gallus gallus domesticus, Varanus salvator, Cuora kamamora amboinensis, Reticulatus malayanus, Oreochromis mossambicus, Rattus rattus, American bullfrog, Donax sp., Polymesoda coaxans, Tenebrio molitor, Lumbricus terrestris, Blatta lateralis, Grammostola rosea, and Penaeus monodon. Species were dissected and their organ lysates/sera/haemolymph were prepared. Cytotoxicity assays were performed using Prostate Cancer cells (PC3), Henrietta Lacks cervical adenocarcinoma cells (HeLa) and human breast adenocarcinoma cells (MCF7) as well as human keratinized skin cells (Hacat), by measuring lactate dehydrogenase release as an indicator for cell death. Growth inhibition assays were performed to determine the effects on cancer cell proliferation. Liquid Chromatography-Mass Spectrometry (LC-MS/MS) was performed for molecular identification. RESULTS: The results revealed that body lysates of Polymesoda coaxans demonstrated more than 99% growth inhibition of all cancer cell lines tested but not on normal Hacat cells. More importantly, the serum of M. reticulatus abolished growth and produced cytotoxicity. Hence these samples were subjected to Liquid Chromatography- Mass Spectrometry (LC-MS/MS), which detected 81 small molecules and putatively identified 20 molecules when matched against the METLIN database. Out of 1094 peptides, 21 peptides were identified, while 1074 peptides were categorized as novel peptides. Based on properties such as peptide amino acid composition, binary profile, dipeptide composition and pseudo-amino acid composition, 306 potential peptides were identified. CONCLUSION: To our knowledge, here for the first time, we report a comprehensive analysis of sera exhibiting cytotoxicity against cancer cell lines tested and identified several molecules using LC-MS/MS.


Assuntos
Poluição Ambiental/análise , Extratos de Tecidos/farmacologia , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Humanos , Especificidade da Espécie , Extratos de Tecidos/química
19.
Int J Pediatr Otorhinolaryngol ; 71(4): 533-8, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17239962

RESUMO

UNLABELLED: Subglottic cysts (SGC) have long been regarded as a rare cause of airway obstruction but through increased awareness an increase in the number of cases of SGC has been reported. OBJECTIVE: This paper describes the pathogenesis and management of SGC. DESIGN: Retrospective case series. Ethical approval not sought. SETTING: Royal Manchester Children's Hospital. PATIENTS: Two hundred and six new referrals for direct laryngotracheobronchoscopy (DLTB) were identified from records between September 2003 and September 2005. MAIN OUTCOMES MEASURED: Age at birth, sex, length of intubation, presenting symptoms, age at presentation, DLTB findings, interventional procedures, and follow-up DLTBs. RESULTS: Fourteen out of 206 (6.8%) infants were diagnosed as with subglottic cysts. This represented the fourth most common cause of upper airway pathology. Thirteen out of 14 (93%) infants were preterm (26.8 weeks S.D. 25.3-28.3 weeks). All infants had been intubated ranging from 1 to 180 days (median 42 days). The onset of symptoms ranged from 1 to 13 months (median 4.25 months). Initially, 8/14 (57.2%) infants had SGC cysts marsupialised with microforceps. A further six cysts (50%) were decapped between 2 and 4 months and one between 6 and 12 months. CONCLUSION: The number of cases of SGC has been increasing over the last three decades and represents the fourth most common causes of airway obstruction in our series. There is a delay in onset of symptoms and high rate of recurrence in the first 4 months. It is therefore prudent to reschedule further endoscopic evaluation between 2 and 4 months and after 6 months should the clinical need arise.


Assuntos
Cistos/etiologia , Cistos/cirurgia , Doenças do Prematuro/etiologia , Doenças do Prematuro/cirurgia , Doenças da Laringe/etiologia , Doenças da Laringe/cirurgia , Broncoscopia , Cistos/patologia , Feminino , Glote , Humanos , Lactente , Recém-Nascido , Recém-Nascido Prematuro , Doenças do Prematuro/patologia , Intubação Intratraqueal , Doenças da Laringe/patologia , Laringoscopia , Masculino , Estudos Retrospectivos , Resultado do Tratamento , Reino Unido
20.
Invest Ophthalmol Vis Sci ; 47(3): 1056-62, 2006 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-16505041

RESUMO

PURPOSE: To determine whether the expression of Acanthamoeba mannose-binding protein (MBP) is associated with the pathogenicity of the parasite in vitro. METHODS: Both active trophozoites and dormant cysts of a pathogenic strain of A. castellanii were analyzed for their ability to bind to corneal epithelium, express MBP, and produce a cytopathic effect (CPE) on host cells. In addition, host cell binding, CPE-inducing ability, and MBP expression pattern of trophozoites of four different isolates of Acanthamoeba with various degrees of in vitro pathogenicity were analyzed. Binding assays were performed with radiolabeled parasites; CPE assays were performed with rabbit corneal epithelial cells as host cells; and the expression of MBP was detected by affinity chromatography of parasite extracts on mannose affinity columns and by immunohistochemical and Western blot analyses. RESULTS: Trophozoites of A. castellanii bound avidly to corneal epithelial cells in a mannose-inhibitable manner, whereas cysts exhibited little binding. The lack of binding of the cysts to host cells was associated with the downregulation of MBP, along with the concomitant loss of CPE. Analysis of trophozoites of five different species of Acanthamoeba exhibiting various degrees of pathogenic potential revealed that the ability of parasites to bind to host cells and produce CPE is directly correlated with the expression of the MBP. Acanthamoeba strains that bound avidly to host cells and produced potent CPE, robustly expressed MBP. In contrast, parasite strains that produced only weak CPE, expressed markedly reduced levels of MBP. CONCLUSIONS: The data demonstrating that the pathogenic potential of Acanthamoeba directly correlates with the expression level of the MBP in conjunction with our published studies showing that Acanthamoeba MBP is a major virulence protein suggest that the amoeba lectin has the potential to serve as a marker of pathogenicity.


Assuntos
Ceratite por Acanthamoeba/parasitologia , Acanthamoeba/metabolismo , Acanthamoeba/patogenicidade , Epitélio Corneano/parasitologia , Lectina de Ligação a Manose/metabolismo , Proteínas de Protozoários/metabolismo , Animais , Western Blotting , Adesão Celular/fisiologia , Células Cultivadas , Cromatografia de Afinidade , Coelhos
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