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1.
BMC Cardiovasc Disord ; 24(1): 100, 2024 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-38341582

RESUMO

BACKGROUND: Dolichoectasia is a rare arterial condition characterized by the dilatation, tortuosity, and elongation of cerebral blood vessels. The vertebrobasilar artery and internal carotid artery are the common sites of dolichoectasia. However, dolichoectasia of the branch arteries, such as the ophthalmic artery (OA), is extremely rare. To the best of our knowledge, this is the first case of ophthalmic dolichoectasia that was successfully treated with endovascular internal coil trapping. CASE PRESENTATION: A 54-year-old female patient presented with transient left ophthalmalgia and visual disturbance. Magnetic resonance imaging revealed a dilated and elongated left OA compressing the optic nerve at the entrance of the optic canal. However, a previous image that was taken 17 years back revealed that the OA was normal, which suggested the change in dolichoectasia was acquired. Cerebral angiography showed that the dilated and tortuous OA was running from the ophthalmic segment of the left internal carotid artery into the orbit. The symptoms could have been attributed to the direct compression of the dolichoectatic OA in the optic canal. A sufficient anastomosis between the central retinal artery and the middle meningeal artery was identified on external carotid angiography with balloon occlusion of the internal carotid artery. Endovascular treatment with internal trapping of the OA was performed due to ophthalmic symptom progression. Internal coil trapping of the OA was performed at the short segment between the OA bifurcation and the entrance of the optic canal. As expected, the central retinal artery was supplied via the middle meningeal artery after the treatment. The transient visual disturbance was immediately resolved. Ophthalmalgia worsened temporarily after the treatment. However, it completely resolved after several days of oral corticosteroid therapy. Postoperative angiography showed that the origin of the OA was occluded and that the OA in the optic canal was shrunk. The flow of the central retinal arteries via the middle meningeal artery was preserved. CONCLUSIONS: OA dolichoectasia is rare, and its pathogenesis and long-term visual prognosis are still unknown. However, endovascular therapy can improve symptom by releasing the pressure site in the optic canal.


Assuntos
Procedimentos Endovasculares , Artéria Oftálmica , Feminino , Humanos , Pessoa de Meia-Idade , Artéria Oftálmica/diagnóstico por imagem , Artéria Oftálmica/cirurgia , Artéria Carótida Interna/diagnóstico por imagem , Artéria Carótida Interna/cirurgia , Angiografia Cerebral , Imageamento por Ressonância Magnética , Dilatação Patológica
2.
Biosensors (Basel) ; 11(8)2021 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-34436074

RESUMO

Traceability analysis, such as identification and discrimination of yeasts used for fermentation, is important for ensuring manufacturing efficiency and product safety during brewing. However, conventional methods based on morphological and physiological properties have disadvantages such as time consumption and low sensitivity. In this study, the resistive pulse method (RPM) was employed to discriminate between Saccharomyces pastorianus and Dekkera anomala and S. pastorianus and D. bruxellensis by measuring the ionic current response of cells flowing through a microsized pore. The height and shape of the pulse signal were used for the simultaneous measurement of the size, shape, and surface charge of individual cells. Accurate discrimination of S. pastorianus from Dekkera spp. was observed with a recall rate of 96.3 ± 0.8%. Furthermore, budding S. pastorianus was quantitatively detected by evaluating the shape of the waveform of the current ionic blockade. We showed a proof-of-concept demonstration of RPM for the detection of contamination of Dekkera spp. in S. pastorianus and for monitoring the fermentation of S. pastorianus through the quantitative detection of budding cells.


Assuntos
Dekkera , Saccharomyces , Brettanomyces , Fermentação , Reação em Cadeia da Polimerase , Saccharomyces cerevisiae
3.
Biosensors (Basel) ; 11(3)2021 Mar 12.
Artigo em Inglês | MEDLINE | ID: mdl-33809382

RESUMO

Immunostaining has been widely used in cancer prognosis for the quantitative detection of cancer cells present in the bloodstream. However, conventional detection methods based on the target membrane protein expression exhibit the risk of missing cancer cells owing to variable protein expressions. In this study, the resistive pulse method (RPM) was employed to discriminate between cultured cancer cells (NCI-H1650) and T lymphoblastoid leukemia cells (CCRF-CEM) by measuring the ionic current response of cells flowing through a micro-space. The height and shape of a pulse signal were used for the simultaneous measurement of size, deformability, and surface charge of individual cells. An accurate discrimination of cancer cells could not be obtained using 1.0 × phosphate-buffered saline (PBS) as an electrolyte solution to compare the size measurements by a microscopic observation. However, an accurate discrimination of cancer cells with a discrimination error rate of 4.5 ± 0.5% was achieved using 0.5 × PBS containing 2.77% glucose as the electrolyte solution. The potential application of RPM for the accurate discrimination of cancer cells from leukocytes was demonstrated through the measurement of the individual cell size, deformability, and surface charge in a solution with a low electrolyte concentration.


Assuntos
Eletrólitos/análise , Proteínas de Membrana/análise , Técnicas Biossensoriais , Linhagem Celular Tumoral , Humanos , Neoplasias/diagnóstico
4.
Thorac Cancer ; 12(10): 1536-1548, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33764690

RESUMO

BACKGROUND: Zinc-finger E-box-binding homeobox 1 (ZEB1) is an important regulator of epithelial-mesenchymal transition (EMT) and is involved in the maintenance of cancer stem cells (CSCs) via miR-200c and BMI1 pathway. Recent studies revealed that ZEB1 contributes to the EMT-mediated acquired resistance to gefitinib in EGFR-mutant non-small cell lung cancer (NSCLC). However, the precise role of ZEB1 in the maintenance of lung CSCs that lead to acquired resistance to gefitinib remains unclear. METHODS: PC9 and HCC827 NSCLC cell lines were treated with high concentrations of gefitinib, and surviving cells were referred to as "gefitinib-resistant persisters" (GRPs). ZEB1 knockdown or overexpression was performed to determine the biological significance of ZEB1 in the CSC features of GRPs, and animal models were studied for in vivo validation. Expression of ZEB1, BMI1, and ALDH1A1 was analyzed by immunohistochemistry in tumor specimens from NSCLC patients with acquired resistance to gefitinib. RESULTS: GRPs had characteristic features of mesenchymal and CSC phenotypes with high expression of ZEB1 and BMI1, and decreased miR-200c, in vitro and in vivo. ZEB1 silencing attenuated the suppression of miR-200c, resulting in the reduction in BMI1 and reversed the mesenchymal and CSC features of GRPs. Furthermore, ZEB1 overexpression induced EMT and increased the levels of CD133- and BMI1-positive GRPs in vitro and gefitinib resistance in vivo. Finally, ZEB1, BMI1, and ALDH1A1 were highly expressed in tumor specimens from EGFR-mutant NSCLC patients with gefitinib resistance. CONCLUSIONS: ZEB1 plays an important role in gefitinib-resistant lung CSCs with EMT features via regulation of miR-200c and BMI1.


Assuntos
Gefitinibe/farmacologia , Neoplasias Pulmonares/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Homeobox 1 de Ligação a E-box em Dedo de Zinco/metabolismo , Animais , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos , Transição Epitelial-Mesenquimal , Feminino , Xenoenxertos , Humanos , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos NOD , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , Inibidores de Proteínas Quinases/farmacologia
5.
Parasitol Int ; 81: 102277, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33370608

RESUMO

In Uganda, artemether-lumefantrine was introduced as an artemisinin-based combination therapy (ACT) for malaria in 2006. We have previously reported a moderate decrease in ex vivo efficacy of lumefantrine in Northern Uganda, where we also detected ex vivo artemisinin-resistant Plasmodium falciparum. Therefore, it is necessary to search for candidate partner alternatives for ACT. Here, we investigated ex vivo susceptibility to four ACT partner drugs as well as quinine and chloroquine, in 321 cases between 2013 and 2018. Drug-resistant mutations in pfcrt and pfmdr1 were also determined. Ex vivo susceptibility to amodiaquine, quinine, and chloroquine was well preserved, whereas resistance to mefloquine was found in 45.8%. There were few cases of multi-drug resistance. Reduced sensitivity to mefloquine and lumefantrine was significantly associated with the pfcrt K76 wild-type allele, in contrast to the association between chloroquine resistance and the K76T allele. Pfmdr1 duplication was not detected in any of the cases. Amodiaquine, a widely used partner drug for ACT in African countries, may be the first promising alternative in case lumefantrine resistance emerges. Therapeutic use of mefloquine may not be recommended in this area. This study also emphasizes the need for sustained monitoring of antimalarial susceptibility in Northern Uganda to develop proper treatment strategies.


Assuntos
Antimaláricos/farmacologia , Resistência a Medicamentos , Plasmodium falciparum/efeitos dos fármacos , Amodiaquina/farmacologia , Artemisininas/farmacologia , Cloroquina/farmacologia , Lumefantrina/farmacologia , Mefloquina/farmacologia , Quinina/farmacologia , Uganda
6.
NMC Case Rep J ; 8(1): 113-116, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35079451

RESUMO

Transient global amnesia (TGA) can be caused by medications, ischemia, metabolic abnormalities, and seizures. We describe two cases of TGA following coil embolization for a basilar-tip aneurysm. A 73-year-old woman developed transient acute anterograde amnesia after coil embolization for a basilar-tip aneurysm. Diffusion-weighted imaging (DWI) revealed an ischemic lesion in the anterior nucleus of the thalamus. A 67-year-old woman developed transient acute amnesia after a stent-assisted coil embolization of a basilar-tip aneurysm. A DWI showed ischemic lesions in the anterior nucleus of the thalamus. Any ischemic changes to areas of the anterior nucleus that are fed by the thalamoperforating and premammillary arteries should be considered in a differential diagnosis for TGA in patients who have undergone coil embolization for a posterior circulation cerebral aneurysm.

7.
Microorganisms ; 8(11)2020 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-33187123

RESUMO

The gold standard for malaria diagnosis is microscopic examination of blood films by expert microscopists. It is important to detect submicroscopic and asymptomatic Plasmodium infections in people, therefore the development of highly sensitive devices for diagnosing malaria is required. In the present study, we investigated whether an imaging cytometer was useful for the highly sensitive quantitative detection of parasites. Whole blood samples were prepared from uninfected individuals spiked with Plasmodium falciparum-infected erythrocytes. Thereafter, erythrocytes were purified using a push column comprising of a syringe filter unit with SiO2-nanofiber filters. After adding the erythrocytes, stained with nuclear stain, to a six-well plate, quantitative detection of the parasites was performed using an image cytometer, CQ1. Imaging of 2.6 × 106 erythrocytes was completed in 3 min, and the limit of detection indicated parasitemia of 0.00010% (≈5 parasites/µL of blood). In addition to rapid, highly sensitive, and quantitative detection, the ease of application and economic costs, image cytometry could be efficiently applied to diagnose submicroscopic parasites in infected people from endemic countries.

8.
Malar J ; 19(1): 373, 2020 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-33076928

RESUMO

BACKGROUND: Several types of insecticides, treating technologies and materials are available for long-lasting insecticide-treated nets (LLINs). The variations may result in different efficacies against mosquitoes and correspondingly infection risks for the Plasmodium falciparum malaria parasite. This cross-sectional study investigated whether infection risk varied among children who slept under different LLIN brands in rural villages of western Kenya. METHODS: Children sleeping under various types of LLINs were tested for P. falciparum infection using a diagnostic polymerase chain reaction (PCR) assay. Data were collected for other potential factors associated with infection risk: sleeping location (with bed/without bed), number of persons sharing the same net, dwelling wall material, gap of eaves (open/close), proportional hole index, socio-economic status, and density of indoor resting anophelines. Bed-net efficacy against the Anopheles gambiae susceptible strain was estimated using the WHO cone test and the tunnel test. The residual insecticide content on nets was measured. RESULTS: Seven LLIN brands were identified, and deltamethrin-based DawaPlus® 2.0 was the most popular (48%) followed by permethrin-based Olyset® Net (28%). The former LLIN was distributed in the area about six months before the present study was conducted, and the latter net was distributed at least three years before. Of 254 children analysed, P. falciparum PCR-positive prevalence was 58% for DawaPlus® 2.0 users and 38% for Olyset® users. The multiple regression analysis revealed that the difference was statistically significant (adjusted OR: 0.67, 95% credible interval: 0.45-0.97), whereas the confounders were not statistically important. Among randomly selected net samples, all DawaPlus® 2.0 (n = 20) and 95% of Olyset® (n = 19) passed either the cone test or the tunnel test. CONCLUSIONS: Olyset® was more effective in reducing infection risk compared with DawaPlus® 2.0. Although the data from the present study were too limited to explain the mechanism clearly, the results suggest that the characteristics of the former brand are more suitable for the conditions, such as vector species composition, of the study area.


Assuntos
Anopheles/efeitos dos fármacos , Mosquiteiros Tratados com Inseticida/estatística & dados numéricos , Inseticidas/farmacologia , Malária Falciparum/epidemiologia , Controle de Mosquitos/instrumentação , Animais , Criança , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Mosquiteiros Tratados com Inseticida/classificação , Quênia/epidemiologia , Masculino , Prevalência , População Rural
9.
Microorganisms ; 8(9)2020 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-32899795

RESUMO

The microscopic examination of Giemsa-stained thin and/or thick blood films (Giemsa microscopy) is the standard method of malaria diagnosis. However, the results of the diagnosis significantly depend on the skills of clinical technicians. Furthermore, sample preparation and analysis are laborious and time-consuming. Therefore, in this study, we investigated if a commercially available fluorescent cell counter, LUNA-FL, was useful for the detection of Plasmodium parasite and the estimation of parasitemia. Whole blood samples from uninfected persons, spiked with P. falciparum-infected erythrocytes, were analysed. Most of the leucocytes and platelets were removed from whole blood samples with SiO2-nanofiber filters set on spin columns. The filtered samples were stained with acridine orange, and automatic detection, as well as counting of erythrocytes and parasites, were performed using LUNA-FL. Whole blood, with various levels of parasites, was analysed by Giemsa microscopy or with LUNA-FL to estimate parasitemia, and a comparative analysis was performed. The coefficient determination value of the regression line was high (R2 = 0.98), indicating that accurate quantitative parasite detection could be performed using LUNA-FL. LUNA-FL has a low running cost; it is compact, fast, and easy to operate, and may therefore be useful for point-of-care testing in the endemic areas.

10.
Sci Rep ; 10(1): 6585, 2020 04 20.
Artigo em Inglês | MEDLINE | ID: mdl-32313065

RESUMO

There is an urgent need to develop an automated malaria diagnostic system that can easily and rapidly detect malaria parasites and determine the proportion of malaria-infected erythrocytes in the clinical blood samples. In this study, we developed a quantitative, mobile, and fully automated malaria diagnostic system equipped with an on-disc SiO2 nanofiber filter and blue-ray devices. The filter removes the leukocytes and platelets from the blood samples, which interfere with the accurate detection of malaria by the blue-ray devices. We confirmed that the filter, which can be operated automatically by centrifugal force due to the rotation of the disc, achieved a high removal rate of leukocytes (99.7%) and platelets (90.2%) in just 30 s. The automated system exhibited a higher sensitivity (100%) and specificity (92.8%) for detecting Plasmodium falciparum from the blood of 274 asymptomatic individuals in Kenya when compared to the common rapid diagnosis test (sensitivity = 98.1% and specificity = 54.8%). This indicated that this system can be a potential alternative to conventional methods used at local health facilities, which lack basic infrastructure.


Assuntos
Testes Diagnósticos de Rotina/métodos , Malária Falciparum/sangue , Técnicas de Diagnóstico Molecular/métodos , Plasmodium falciparum/isolamento & purificação , Plaquetas/parasitologia , Criança , Pré-Escolar , Eritrócitos/parasitologia , Feminino , Fluorescência , Humanos , Quênia/epidemiologia , Leucócitos/parasitologia , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Nanofibras/química , Plasmodium falciparum/patogenicidade , Reação em Cadeia da Polimerase , Dióxido de Silício/química
11.
Parasitol Int ; 73: 101941, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31442664

RESUMO

Polymerase chain reaction (PCR) is an essential diagnostic method for highly sensitive detection of Plasmodium-infected erythrocytes in patients with malaria. This study compared the performance of filter papers used for the preparation of dried blood spots (DBS) in detecting Plasmodium by PCR. Whole blood spiked with P. falciparum-infected erythrocytes to obtain samples with various levels of parasitemia were applied to Whatman 3MM Chr papers, FTA Cards, or FTA Elute Cards to prepare the DBS. DNA was purified from the DBS using a DNA purification kit and used as the template for nested PCR. In probit analysis, the estimated limit of detection (LoD) was 5.5 parasites/µL blood for Whatman 3MM Chr papers and FTA Cards and 1.6 parasites/µL blood for the FTA Elute Card. This result suggested that the DBS prepared on an FTA Elute Card yield the best template DNA for subsequent high-sensitivity PCR-based detection of P. falciparum-infected erythrocytes. This finding can help improve the accuracy of malarial diagnostic tests.


Assuntos
DNA de Protozoário/análise , Teste em Amostras de Sangue Seco/métodos , Malária Falciparum/diagnóstico , Plasmodium falciparum/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , RNA Ribossômico 18S/análise , Testes Diagnósticos de Rotina/instrumentação , Humanos , Limite de Detecção
12.
Biosens Bioelectron ; 132: 375-381, 2019 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-30901727

RESUMO

A highly sensitive diagnostic system for determining low-density infections that are missed by conventional methods is necessary to detect the carriers of Plasmodium falciparum. A fluorescent blue-ray optical system with a polycarbonate scan disc was developed to detect P. falciparum-infected red blood cells (Pf-iRBCs), and nine samples could be analyzed simultaneously. The cultured P. falciparum strain 3D7 was used to examine the potential of the system for diagnosing malaria. After an RBC suspension had been applied to the disc, the cells were dispersed on the disc by rotation. During the 10 min standing period to allow the RBCs to settle on the disc surface, the cells were simultaneously stained with nuclear fluorescence staining dye Hoechst 34580, which was previously adsorbed on the disc surface. RBCs were arranged on the disc surface as a monolayer by removing excess cells through momentary rotation. Over 1.1 million RBCs remained on the disc for fluorescence analysis. A portable, battery-driven fluorescence image reader was employed to detect fluorescence-positive RBCs for approximately 40 min. A good correlation between examination of Giemsa-stained RBCs by light microscopy and the developed system was demonstrated in the parasitemia range of 0.0001-1.0% by linear regression analysis (R2 = 0.99993). The limit of detection of 0.00020% and good reproducibility for parasitemia determination were observed. The ability of the developed system to detect sub-microscopic low-density Pf-iRBCs and provide accurate quantitative evaluation with easy operation was demonstrated.


Assuntos
Técnicas Biossensoriais/instrumentação , Eritrócitos/parasitologia , Malária Falciparum/parasitologia , Dispositivos Ópticos , Imagem Óptica/instrumentação , Plasmodium falciparum/isolamento & purificação , Benzimidazóis/análise , Desenho de Equipamento , Corantes Fluorescentes/análise , Humanos , Limite de Detecção , Malária Falciparum/diagnóstico , Parasitemia/diagnóstico , Parasitemia/parasitologia , Reprodutibilidade dos Testes
13.
J Parasitol ; 105(1): 69-74, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30807712

RESUMO

Malaria is caused by Plasmodium spp., a parasitic protist that infects erythrocytes. A method that can detect the parasite with high sensitivity and that can identify the parasite species is urgently required for the control of malaria. The cell microarray chip was made using polystyrene with 200 cone-shaped frustum microchambers (800-µm top diameter, 636-µm bottom diameter, and 225 µm deep). Approximately 3,000 erythrocytes could be accommodated in each microchamber with monolayer formation, there being 60,000 erythrocytes in total microchambers on a cell microarray. Plasmodium could be quantitatively detected with high sensitivity with the use of cell microarray chips. Plasmodium parasitizing in erythrocytes was labeled with a cell-permeant fluorescent nucleic acid stain (SYTO 21), which could be detected in erythrocytes in the microchambers. Next, we used loop-mediated isothermal amplification (LAMP) in the microchambers (on-chip LAMP) to identify the parasite species detected in the microchambers. LAMP was performed in the microchambers (in a reaction volume of 0.09 µl) using Plasmodium falciparum-infected erythrocytes as the template and specific primers targeting 18S rRNA. To avoid evaporation of the reaction buffer during heat treatment, mineral oil was overlaid on each microchamber and the cell microarray chips were heated at 63 C for 1 hr. The results of on-chip LAMP were assessed using a portable ultraviolet transilluminator. We showed that this method has the potential for detection of parasites in 600,000 erythrocytes and for identification of the parasite species on a cell microarray chip. In conclusion, the parasites can be detected quantitatively with high sensitivity, and the species can be identified with the use of cell microarray chips.


Assuntos
Eritrócitos/parasitologia , Técnicas de Amplificação de Ácido Nucleico/métodos , Plasmodium/isolamento & purificação , Humanos , Microscopia de Fluorescência , Técnicas de Amplificação de Ácido Nucleico/normas , Plasmodium/classificação , Plasmodium/genética , Sensibilidade e Especificidade , Análise Serial de Tecidos
14.
Parasitol Int ; 69: 54-58, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30468871

RESUMO

It is very important to reduce the costs involved in malarial drug development by small-scale culture of Plasmodium falciparum, and automation of the assay system for drug efficacy against the parasites for high-throughput screening. In this study, we report that P. falciparum-infected erythrocytes can be stably cultured on µ-Slide Angiogenesis, which is used to investigate angiogenesis in tube formation assays, followed by automatic counting of the infection rate (parasitaemia). After 10 µL of parasite-infected erythrocytes were added to the inner well of µ-Slide Angiogenesis to prevent a multilayer of erythrocytes, 30 µL of silicon oil was overlaid on the culture medium to avoid evaporation of the medium, leading to stable small-scale parasite cultivation. The parasites were stained with a cell-permeant fluorescent nucleic acid stain (SYTO21) followed by cultivation. After taking bright field and fluorescent images using an inverted microscope, the infection rate could be calculated automatically by counting the number of erythrocytes and parasites using MetaMorph Offline software. The effect of anti-malarial drugs on parasite growth could be investigated on µ-Slide Angiogenesis, in which the parasite culture was added to the inner wells containing the drugs followed by their cultivation. Taken together, this method may be useful for image-based screening for anti-malarial drug candidates with automatic counting of parasite infection rates.


Assuntos
Antimaláricos/farmacologia , Avaliação Pré-Clínica de Medicamentos , Eritrócitos/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Automação , Técnicas de Cultura , Desenvolvimento de Medicamentos , Humanos , Microscopia , Imagem Óptica , Testes de Sensibilidade Parasitária , Plasmodium falciparum/crescimento & desenvolvimento , Coloração e Rotulagem
15.
Malar J ; 17(1): 235, 2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29914490

RESUMO

BACKGROUND: Five species of Plasmodium are known to infect humans. For proper treatment of malaria, accurate identification of the parasite species is crucial. The current gold standard for malaria diagnosis is microscopic examination of Giemsa-stained blood smears. Since the parasite species are identified by microscopists who manually search for the parasite-infected red blood cells (RBCs), misdiagnosis due to human error tends to occur in case of low parasitaemia or mixed infection. Then, molecular methods, such as polymerase chain reaction or loop-mediated isothermal amplification (LAMP), are required for conclusive identification of the parasite species. However, since molecular methods are highly sensitive, false-positive results tend to occur due to contamination (carry over) or the target gene products may be detected even after clearance of the parasites from the patient's blood. Therefore, accurate detection of parasites themselves by microscopic examination is essential for the definitive diagnosis. Thus, the method of in situ LAMP for the parasites was developed. RESULTS: Red blood cell suspensions, including cultured Plasmodium falciparum, strain 3D7, infected-RBCs, were dispersed on cyclic olefin copolymer (COC) plate surfaces rendered hydrophilic by reactive ion-etching treatment using a SAMCO RIE system (hydrophilic-treated), followed by standing for 10 min to allow the RBCs to settle down on the plate surface. By rinsing the plate with RPMI 1640 medium, monolayers of RBCs formed on almost the entire plate surface. The plate was then dried with a hair drier. The RBCs were fixed with formalin, followed by permeabilization with Triton X-100. Then, amplification of the P. falciparum 18S rRNA gene by the LAMP reaction with digoxigenin (DIG)-labelled dUTP and a specific primer set was performed. Infected RBCs as fluorescence-positive cells with anti-DIG antibodies conjugated with fluorescein using fluorescent microscopy could be detected. CONCLUSIONS: The present work shows that the potential of in situ LAMP for the identification of Plasmodium species at the single cell level on hydrophilic-treated COC palates, allowing highly sensitive and accurate malaria diagnosis. The findings will improve the efficacy of the gold standard method for malaria diagnosis.


Assuntos
Malária Falciparum/diagnóstico , Microscopia/métodos , Técnicas de Amplificação de Ácido Nucleico/métodos , Parasitemia/diagnóstico , Plasmodium falciparum/isolamento & purificação , Humanos , RNA de Protozoário/análise , RNA Ribossômico 18S/análise
16.
Emerg Infect Dis ; 24(4): 718-726, 2018 04.
Artigo em Inglês | MEDLINE | ID: mdl-29553316

RESUMO

Because ≈90% of malaria cases occur in Africa, emergence of artemisinin-resistant Plasmodium falciparum in Africa poses a serious public health threat. To assess emergence of artemisinin-resistant parasites in Uganda during 2014-2016, we used the recently developed ex vivo ring-stage survival assay, which estimates ring-stage-specific P. falciparum susceptibility to artemisinin. We conducted 4 cross-sectional surveys to assess artemisinin sensitivity in Gulu, Uganda. Among 194 isolates, survival rates (ratio of viable drug-exposed parasites to drug-nonexposed controls) were high (>10%) for 4 isolates. Similar rates have been closely associated with delayed parasite clearance after drug treatment and are considered to be a proxy for the artemisinin-resistant phenotype. Of these, the PfKelch13 mutation was observed in only 1 isolate, A675V. Population genetics analysis suggested that these possibly artemisinin-resistant isolates originated in Africa. Large-scale surveillance of possibly artemisinin-resistant parasites in Africa would provide useful information about treatment outcomes and help regional malaria control.


Assuntos
Antimaláricos/farmacologia , Artemisininas/farmacologia , Resistência a Medicamentos , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Plasmodium falciparum/efeitos dos fármacos , Antimaláricos/uso terapêutico , Artemisininas/uso terapêutico , Pré-Escolar , Estudos Transversais , Feminino , Genótipo , História do Século XXI , Humanos , Malária Falciparum/história , Malária Falciparum/mortalidade , Masculino , Mutação , Fenótipo , Plasmodium falciparum/genética , Taxa de Sobrevida , Uganda/epidemiologia , Sequenciamento Completo do Genoma
17.
J Parasitol ; 104(3): 283-288, 2018 06.
Artigo em Inglês | MEDLINE | ID: mdl-29378156

RESUMO

The cell microarray chip is a polystyrene plate with 20,944 microchambers, and it is used to detect red blood cells (RBCs) infected with the causative agent of malaria, Plasmodium. Plasmodium-infected red blood cells (iRBCs) stained with a nuclear staining dye (SYTO 21) form a monolayer on the bottom of the microchambers, and about 130 RBCs are accommodated in each such microchamber of the chip. The iRBCs in the RBC monolayer (containing 2.7 million RBCs) can be identified using a fluorescence detector, and the infection rate can be calculated by counting the number of fluorescent-positive RBCs. This diagnostic device is highly sensitive and hence advantageous for early diagnosis of malaria infections in endemic areas. However, a standard positive control for Plasmodium-infected RBCs is required to ensure that the reagents and detectors of these cell microarray chips are working efficiently in remote endemic areas. Here, we introduce "pseudo-iRBC beads," which consist of a mixture of DEA beads mimicking RBCs and DEA beads coated with nucleic acids mimicking nuclei of the parasite. These beads can be stained with SYTO 21, applied onto the cell microarray chip to form a monolayer, and detected using the fluorescence detector in the same way as iRBCs. Therefore, the introduction of pseudo-iRBC beads as a positive control ensures unbiased malaria diagnoses with the cell microarray chip device in remote endemic areas.


Assuntos
Eritrócitos/parasitologia , Malária/diagnóstico , Plasmodium/fisiologia , Análise Serial de Tecidos/métodos , DNA/química , Microscopia de Fluorescência , Microesferas , Plasmodium/isolamento & purificação
18.
J Colloid Interface Sci ; 512: 474-479, 2018 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-29096108

RESUMO

HYPOTHESIS: The C3N4 as a cheap and clean photocatalyst shows suitable band gap to splitting water and spectral response. However the poor conductivity of C3N4 limits the photocatalytic hydrogen evolution rate. The combination of C3N4 and high conductivity materials will enhance the separation of photo-generated carriers and thus enhance the photocatalytic activity. As many carbon materials have been tried, the mesoporous carbon should be a good candidate to solve this problem. EXPERIMENTS: A photocatalytic system with C3N4 and mesoporous carbon has been designed to test the photocatalytic performance of both the photocatalytic hydrogen evolution and the photocatalytic degradation of methylene blue. The results of EPR, EIS and PL spectra were given to further understand the photo-generated carrier and its transfer. FINDINGS: The enhancement of the highest hydrogen evolution rate is 48% from 69 to 102 µmol/h by mesoporous carbon/C3N4 sample. The existence of small amount of mesoporous carbon can facilitate the photogenerated carrier separation, thus enhancing the photocatalytic performance. In the meantime, the introduction of mesoporous carbon into C3N4 is beneficial for improving electron delocalization and conduction electrons and increasing the optical absorption.

19.
Malar J ; 16(1): 321, 2017 08 08.
Artigo em Inglês | MEDLINE | ID: mdl-28789644

RESUMO

BACKGROUND: Malaria is a red blood cell (RBC) infection caused by Plasmodium parasites. To determine RBC infection rate, which is essential for malaria study and diagnosis, microscopic evaluation of Giemsa-stained thin blood smears on glass slides ('Giemsa microscopy') has been performed as the accepted gold standard for over 100 years. However, only a small area of the blood smear provides a monolayer of RBCs suitable for determination of infection rate, which is one of the major reasons for the low parasite detection rate by Giemsa microscopy. In addition, because Giemsa microscopy is exacting and time-consuming, automated counting of infection rates is highly desirable. RESULTS: A method that allows for microscopic examination of Giemsa-stained cells spread in a monolayer on almost the whole surface of hydrophilic-treated cyclic olefin copolymer (COC) plates was established. Because wide-range Giemsa microscopy can be performed on a hydrophilic-treated plate, the method may enable more reliable diagnosis of malaria in patients with low parasitaemia burden. Furthermore, the number of RBCs and parasites stained with a fluorescent nuclear staining dye could be counted automatically with a software tool, without Giemsa staining. As a result, researchers studying malaria may calculate the infection rate easily, rapidly, and accurately even in low parasitaemia. CONCLUSION: Because the running cost of these methods is very low and they do not involve complicated techniques, the use of hydrophilic COC plates may contribute to improved and more accurate diagnosis and research of malaria.


Assuntos
Sangue/parasitologia , Processamento de Imagem Assistida por Computador/instrumentação , Malária Falciparum/diagnóstico , Microscopia/instrumentação , Parasitemia/diagnóstico , Plasmodium falciparum/isolamento & purificação , Automação , Corantes Azur/química , Cicloparafinas/química , Interações Hidrofóbicas e Hidrofílicas , Malária Falciparum/parasitologia , Microscopia/economia , Parasitemia/parasitologia
20.
Physiol Rep ; 4(21)2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27905298

RESUMO

Birt-Hogg-Dubé syndrome (BHDS) is an autosomal dominant inherited disorder caused by germline mutations in the FLCN gene, and characterized by skin fibrofolliculomas, multiple lung cysts, spontaneous pneumothorax, and renal neoplasms. Pulmonary manifestations frequently develop earlier than other organ involvements, prompting a diagnosis of BHDS However, the mechanism of lung cyst formation and pathogenesis of pneumothorax have not yet been clarified. Fibroblasts were isolated from lung tissues obtained from patients with BHDS (n = 12) and lung cancer (n = 10) as controls. The functional abilities of these lung fibroblasts were evaluated by the tests for chemotaxis to fibronectin and three-dimensional (3-D) gel contraction. Fibroblasts from BHDS patients showed diminished chemotaxis as compared with fibroblasts from controls. Expression of fibronectin and TGF-ß1 was significantly reduced in BHDS fibroblasts when assessed by qPCR Addition of TGF-ß1 in culture medium of BHDS lung fibroblasts significantly restored these cells' abilities of chemotaxis and gel contraction. Human fetal lung fibroblasts (HFL-1) exhibited reduced chemotaxis and 3-D gel contraction when FLCN expression was knocked down. To the contrary, a significant increase in chemotactic activity toward to fibronectin was demonstrated when wild-type FLCN was overexpressed, whereas transduction of mutant FLCN showed no effect on chemotaxis. Our results suggest that FLCN is associated with chemotaxis in lung fibroblasts. Together with reduced TGF-ß1 expression by BHDS lung fibroblasts, a state of FLCN haploinsufficiency may cause lung fibroblast dysfunction, thereby impairing tissue repair. These may reveal one mechanism of lung cyst formation and pneumothorax in BHDS patients.


Assuntos
Síndrome de Birt-Hogg-Dubé/genética , Fibroblastos/metabolismo , Haploinsuficiência/genética , Pulmão/metabolismo , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Supressoras de Tumor/metabolismo , Adulto , Síndrome de Birt-Hogg-Dubé/patologia , Quimiotaxia/fisiologia , Cistos/patologia , Feminino , Fibroblastos/patologia , Mutação em Linhagem Germinativa , Humanos , Pulmão/patologia , Pneumopatias/diagnóstico , Pneumopatias/genética , Masculino , Microscopia Confocal/métodos , Pessoa de Meia-Idade , Pneumotórax/diagnóstico , Pneumotórax/genética , Pneumotórax/cirurgia , Proteínas Proto-Oncogênicas/genética , Pele/patologia , Dermatopatias/diagnóstico , Dermatopatias/genética , Fator de Crescimento Transformador beta1/metabolismo , Proteínas Supressoras de Tumor/genética
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