RESUMO
OBJECTIVES: Cladribine tablets (CLAD) for adult patients with highly active relapsing multiple sclerosis (RMS) have been available in Italy since 2018. We aimed to assess predictors of no-evidence-of-disease-activity-3 (NEDA-3) status after 24 months of the last dose of CLAD. RESULTS: We included 88 patients (70.5% female, mean age at CLAD start 35.4 ± 11.4). Eighteen patients were treatment naïve, 48 switched to CLAD from a First line Disease Modifying Drug (DMD), and 22 from Second line DMDs. All patients were observed for a median follow-up time of 2.4 (1-4) years after the last dose of CLAD. Forty-nine patients (55.7%) showed NEDA at the last available follow-up. Naïve patients (p = 0.001), those with a lower number of previous DMDs (p < 0.001) and, even though not significantly, those switching from first line DMDs (p = 0.069) were more likely NEDA3 at the last available follow-up. In a subgroup of 30 patients (34%), Serum Light Neurofilaments (sNFL) levels showed a decrease from baseline to the 24 months of follow-up, statistically significant from baseline to the sixth month, and from the first to the second year detection. sNFL levels at 12th month showed a strong inverse correlation with the time to NEDA3 loss. CONCLUSIONS: Our experience provides information for the 2-years after the last dose of CLAD, confirming a higher effectiveness of CLAD when placed early in the treatment algorithm. Given the ongoing expansion of the therapeutic landscape in MS, sNfL could support individualized decision-making, used as blood-based biomarker for CLAD responses in clinical practice.
Assuntos
Cladribina , Imunossupressores , Humanos , Cladribina/uso terapêutico , Cladribina/administração & dosagem , Feminino , Masculino , Adulto , Pessoa de Meia-Idade , Imunossupressores/uso terapêutico , Imunossupressores/administração & dosagem , Resultado do Tratamento , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/sangue , Seguimentos , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla/sangueRESUMO
BACKGROUND: Fingolimod (FTY) induces sequestration of lymphocytes in secondary lymphoid organs and the average lymphocyte recovery following discontinuation takes 1-2 months. It has been hypothesized that the therapeutic effects of subsequent cell-depleting agents may be compromised if initiated before lymphocyte recovery has occurred. OBJECTIVE: To assess the risk of relapses following FTY discontinuation and the initiation of a B/T cell-depleting agent in relation to washout duration using data from the Italian MS Register. METHODS: The risk of relapses was assessed in relation to different washout durations (< 6, 6-11, 12-17 and > / = 18 weeks) in patients starting alemtuzumab, rituximab, ocrelizumab or cladribine following FTY discontinuation. RESULTS: We included 329 patients in the analysis (226F, 103 M; mean age 41 ± 10 years). During the cell-depleting treatment, the incidence rate ratio for a relapse was significantly greater in patients with a washout period of 12-17 and > / = 18 weeks compared to the reference period (< 6 weeks). The risk of a relapse was significantly influenced by the occurrence of relapses during FTY treatment and by washout length, with hazard ratios markedly increasing with the washout duration. CONCLUSION: The risk of relapses increases with the washout duration when switching from FTY to lymphocyte-depleting agents.
Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Adulto , Alemtuzumab/uso terapêutico , Cloridrato de Fingolimode/uso terapêutico , Humanos , Imunossupressores/efeitos adversos , Pessoa de Meia-Idade , Esclerose Múltipla/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/tratamento farmacológico , Esclerose Múltipla Recidivante-Remitente/epidemiologia , RecidivaRESUMO
This paper presents a static output feedback controller design for discrete-time nonlinear systems exactly represented by Takagi-Sugeno models. By introducing past states in the control law as well as in the Lyapunov function, more relaxed results are obtained. Different conditions in terms of linear matrix inequalities are provided. The proposed conditions are less demanding than the ones in the literature. This is illustrated via numerical examples.
RESUMO
Several advances have been made in data assimilation techniques applied to blood flow modeling. Typically, idealized boundary conditions, only verified in straight parts of the vessel, are assumed. We present a general approach, on the basis of a Dirichlet boundary control problem, that may potentially be used in different parts of the arterial system. The relevance of this method appears when computational reconstructions of the 3D domains, prone to be considered sufficiently extended, are either not possible, or desirable, because of computational costs. On the basis of taking a fully unknown velocity profile as the control, the approach uses a discretize then optimize methodology to solve the control problem numerically. The methodology is applied to a realistic 3D geometry representing a brain aneurysm. The results show that this data assimilation approach may be preferable to a pressure control strategy and that it can significantly improve the accuracy associated to typical solutions obtained using idealized velocity profiles.
Assuntos
Velocidade do Fluxo Sanguíneo/fisiologia , Hemodinâmica , Algoritmos , Humanos , Aneurisma Intracraniano/diagnóstico por imagem , Aneurisma Intracraniano/fisiopatologia , Tomografia Computadorizada por Raios XRESUMO
The concentration of tumor markers in body fluids can be used for diagnosis and prognosis of patients. This study aimed to investigate the performance of tumor markers cytokeratin 19 fragment (CYFRA 21-1), cancer-associated antigen 72-4 (CA 72-4) and carcinoembryonic antigen (CEA) in the neoplastic and non-neoplastic canine effusions. In thirty-two neoplastic (n=16) and non-neoplastic (n=16) samples of canine thoracic or abdominal effusions, tumor markers were measured. Significant statistical difference was found only for the CYFRA 21-1 marker. The levels were significantly higher for the neoplastic group. The lack of significance between groups for markers CA 72-4 and CEA can be explained by the presence of other diseases in the non-neoplastic group, causing elevated levels of these markers. This study concludes that CYFRA 21-1 performed well, showing good sensitivity, specificity and accuracy in the diagnosis of neoplastic effusions in dogs. However, further investigations are necessary in patients with malignancy as those with benign effusions...
Os níveis de marcadores tumorais em líquidos corporais podem ser usados para diagnóstico e prognóstico de pacientes. Este estudo objetiva investigar o desempenho dos marcadores tumorais fragmento de citoqueratina 19 (CYFRA 21-1), antígeno asociado ao câncer 72-4 (CA 72-4) e antígeno carcinoembrionário (CEA) em efusões caninas neoplásicas e não neoplásicas. Os marcadores tumorais foram mensurados em 32 amotras de efusões torácicas e abdominais de cães, 16 neoplásicas e 16 não neoplásicas. Foi encontrada diferença estatística somente para o marcador CYFRA 21-1, onde os níveis foram significativamente altos no grupo neoplásico. A falta de significância entre os grupos de marcadores CA 72-4 e CEA pode ser explicada pela presença de outras doenças no grupo não neoplásico, o que causou elevação dos níveis destes marcadores. Este estudo conclui que o marcador CYFRA 21-1 teve bom desempenho, pois mostrou boa sensibilidade, especificidade e acurácia no diagnóstico de efusões neoplásicas em cães. Entretanto, mais estudos são necessários tanto em pacientes portadores de efusões benignas quanto malignas...
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Animais , Cães , Biomarcadores Tumorais/análise , Neoplasias/diagnóstico , Neoplasias/veterinária , Queratinas/administração & dosagemRESUMO
The mistletoe Psittacanthus robustus was studied as a model to link flower phenology and nectar secretion strategy to pollinator behaviour and the reproductive consequences for the plant. The bright-coloured flowers presented diurnal anthesis, opened asynchronously throughout the rainy season and produced copious dilute nectar as the main reward for pollinators. Most nectar was secreted just after flower opening, with little sugar replenishment after experimental removals. During the second day of anthesis in bagged flowers, the flowers quickly reabsorbed the offered nectar. Low values of nectar standing crop recorded in open flowers can be linked with high visitation rates by bird pollinators. Eight hummingbirds and two passerines were observed as potential pollinators. The most frequent flower visitors were the hummingbirds Eupetomena macroura and Colibri serrirostris, which actively defended flowering mistletoes. The spatial separation between anthers, stigma and nectar chamber promotes pollen deposition on flapping wings of hovering hummingbirds that usually probe many flowers per visit. Seed set did not differ between hand-, self- and cross-pollinated flowers, but these treatments set significantly more seeds than flowers naturally exposed to flower visitors. We suggest that the limitation observed in the reproductive success of this plant is not related to pollinator scarcity, but probably to the extreme frequency of visitation by territorial hummingbirds. We conclude that the costs and benefits of plant reproduction depend on the interaction strength between flowers and pollinators, and the assessment of nectar secretion dynamics, pollinator behaviour and plant breeding system allows clarification of the complexity of such associations.
Assuntos
Aves/fisiologia , Loranthaceae/fisiologia , Néctar de Plantas/metabolismo , Polinização , Animais , Comportamento Animal , Flores/fisiologia , Reprodução , TerritorialidadeAssuntos
Comportamento do Adolescente/psicologia , Delinquência Juvenil/prevenção & controle , Relações Pais-Filho , Valores Sociais , Violência/prevenção & controle , Adolescente , Relações Familiares , Feminino , Humanos , Delinquência Juvenil/estatística & dados numéricos , Grupo Associado , Pennsylvania , Características de Residência , Fatores de Risco , Meio Social , Violência/estatística & dados numéricosRESUMO
The objective was to use the bovine viral diarrhea virus (BVDV) as a model to assess the risk of infectious disease transmission in the system of in vitro embryo production and transfer via somatic cell nuclear transfer (SCNT) technology. The risks of BVDV transmission in the SCNT embryo production were previously evaluated. In that in vitro study, following standard operating procedures (SOP), including pre-nuclear transfer donor cell testing, oocyte decontamination and virus-free cell and embryo culture conditions, SCNT embryos produced were free of detectable viral RNA. The current study focused on the evaluation of the potential risk of disease transmission from SCNT embryos to recipients, and the risk of producing persistently infected animals via SCNT embryo transfer. Blood samples were collected from 553 recipients of SCNT embryos and 438 cloned calves and tested for the presence of BVDV viral RNA via a sensitive real time PCR method. All samples tested were negative. These results, in conjunction with the previous in vitro study, confirmed that the established SCNT embryo production and transfer system is safe and presents no detectable risk of disease transmission.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/transmissão , Vírus da Diarreia Viral Bovina/fisiologia , Transferência Embrionária/veterinária , Transmissão Vertical de Doenças Infecciosas/veterinária , Técnicas de Transferência Nuclear/veterinária , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/virologia , Bovinos , Clonagem de Organismos , Feminino , Doação de Oócitos/veterinária , Oócitos/virologia , Gravidez , Reprodutibilidade dos Testes , Fatores de Risco , Coleta de Tecidos e Órgãos/veterináriaRESUMO
The objective was to assess the risk of transmission of bovine viral diarrhea virus (BVDV) through embryo production via somatic cell nuclear transfer (SCNT), with oocytes obtained from persistently infected (PI) donors. Using ultrasound-guided follicular aspiration following superstimulation, oocytes were obtained from five female beef cattle, including three that were PI and two that were negative for BVDV. In the three PI cattle, seven aspirations yielded 32 oocytes (PI-1: three aspirations yielding six oocytes; PI-2: two aspirations yielding 14 oocytes; and PI-3: two aspirations yielding 12 oocytes). The oocyte recovery rate was better in negative control cattle, with 32 oocytes obtained from the two cattle in a single superstimulation and aspiration session. Oocytes were processed individually for SCNT, evaluated, and tested for BVDV. Nearly all (31/32) oocytes from the three PI donors were positive for BVDV by PCR, with detected viral RNA copy number ranging from 1 to 1.1 x 10(5). The proportion of oocytes acceptable for SCNT embryo production (based on oocyte quality and maturation status) was only 16 to 35% from PI donors, but was 81% from control donors. Therefore, routine testing of unacceptable (discarded) oocytes could be an effective approach to identify batches that might contain infected oocytes from PI donors. Identification and removal of high-risk batches of oocytes would minimize the risk of BVDV transmission through SCNT embryo production.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Doença das Mucosas por Vírus da Diarreia Viral Bovina/transmissão , Vírus da Diarreia Viral Bovina , Técnicas de Transferência Nuclear , Oócitos/virologia , Animais , Bovinos , Vírus da Diarreia Viral Bovina/genética , Feminino , Líquido Folicular/virologia , Doação de Oócitos/veterinária , Reação em Cadeia da Polimerase , RNA Viral/análise , RNA Viral/sangue , Fatores de Risco , Coleta de Tecidos e Órgãos/métodos , Coleta de Tecidos e Órgãos/veterináriaRESUMO
The objective of this study was to perform a comprehensive risk assessment on infectious disease transmission in the system of in vitro embryo production via somatic cell nucleus transfer (SCNT) technology using bovine viral diarrhea virus (BVDV) as a model. The risks of BVDV transmission in each step of the SCNT embryo production procedure, from donor cells to preimplantation SCNT embryo culture, were carefully examined using a sensitive real-time polymerase chain reaction assay. The identified primary source of BVDV transmission in SCNT embryo production was donor cell infection, most likely caused by contaminated fetal bovine serum in the culture medium. The risk of disease transmission through contaminated oocytes from an abattoir was relatively low, and it can be greatly minimized by cumulus cell removal and adequate oocyte washing procedures. Of the 200 cumulus-oocyte complexes (COCs) and more than 1500 cumulus cell-free oocyte (CFO) samples collected from multiple sources over a course of 7 months, only 2.5% of the COCs were BVDV positive, and all of the CFOs (100%) were BVDV negative. To evaluate the risk of BVDV introduction during in vitro SCNT embryo culture, 324 SCNT embryos were produced from 18 different cell lines using oocytes from 26 different batches collected over a course of 9 months. The embryos were cultured in vitro for 7 days and then tested for BVDV. All of the 324 SCNT embryos (100%) were negative, indicating that the embryo culture system is virtually risk-free for BVDV transmission. Based on these results, a standard operational protocol (SOP) for SCNT embryo production was proposed to greatly minimize the risk of BVDV transmission through the SCNT embryo production system. This SOP could be a starting point to produce a SCNT system that is virtually risk-free for disease transmission in general.
Assuntos
Doença das Mucosas por Vírus da Diarreia Viral Bovina/transmissão , Bovinos/virologia , Clonagem de Organismos/veterinária , Vírus da Diarreia Viral Bovina/isolamento & purificação , Técnicas de Transferência Nuclear/veterinária , Animais , Blastocisto/virologia , Bovinos/embriologia , Linhagem Celular , Meios de Cultura , Vírus da Diarreia Viral Bovina/genética , Técnicas de Cultura Embrionária/veterinária , Feminino , Sangue Fetal/virologia , Fibroblastos/ultraestrutura , Fibroblastos/virologia , Oócitos/virologia , Reação em Cadeia da Polimerase , RNA Viral/química , Medição de Risco , Alinhamento de SequênciaRESUMO
The objective was to develop a method to accurately and efficiently detect minute amounts of bovine viral diarrhea virus (BVDV) associated with a single embryo. There are two major challenges for BVDV detection in a single embryo: the test sensitivity and the efficiency of viral molecule recovery. These become even more critical when attempts are made to detect BVDV infections that occurred naturally, not through artificial exposure of the embryos to high affinity BVDV strains. We have developed a one-step sample preparation method that has increased the viral molecule recovery rate compared to the standard RNA isolation procedure by 7-100-fold. Instead of using the traditional virus exposure approach, we generated BVDV positive embryos via somatic cell nuclear transfer (SCNT) technology using BVDV positive donor cells. By combining the highly efficient sample preparation procedure with a sensitive one-step, real-time PCR system, we have developed a sensitive test that allows detection of as low as two copies of BVDV in a single embryo. This method will allow systematic risk assessment for BVDV transmission during in vitro embryo production via IVF or SCNT procedures.
Assuntos
Blastocisto/virologia , Bovinos/embriologia , Vírus da Diarreia Viral Bovina/isolamento & purificação , Animais , Doença das Mucosas por Vírus da Diarreia Viral Bovina/prevenção & controle , Doença das Mucosas por Vírus da Diarreia Viral Bovina/transmissão , Técnicas de Transferência Nuclear , Reação em Cadeia da Polimerase/métodos , Reação em Cadeia da Polimerase/veterinária , RNA Viral/isolamento & purificação , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
Interspecies hybrids between distinct species of the genus Xiphophorus are often used in varied research investigations to identify genomic regions associated with the inheritance of complex traits. There are 24 described Xiphophorus species and a greater number of pedigreed strains; thus, the number of potential interspecies hybrid cross combinations is quite large. Previously, select Xiphophorus experimental crosses have been shown to exhibit differing characteristics between parental species and among the hybrid fishes derived from crossing them, such as widely differing susceptibilities to chemical or physical agents. For instance, genomic regions harboring tumor suppressor and oncogenes have been identified via linkage association of these loci with a small set of established genetic markers. The power of this experimental strategy is related to the number of genetic markers available in the Xiphophorus interspecies cross of interest. Thus, we have undertaken the task of expanding the suite of easily scored markers by characterization of Xiphophorus microsatellite sequences. Using a cross between Xiphophorus maculatus and X. andersi, we report a linkage map predominantly composed of microsatellite markers. All 24 acrocentric chromosome sets of Xiphophorus are represented in the assembled linkage map with an average intergenomic distance of 7.5 cM. Since both male and female F1 hybrids were used to produce backcross progeny, these recombination rates were compared between "male" and "female" maps. Although several genomic regions exhibit differences in map length, male- and female-derived maps are similar. Thus Xiphophorus, in contrast to zebrafish, Danio rerio, and several other vertebrate species, does not show sex-specific differences in recombination. The microsatellite markers we report can be easily adapted to any Xiphophorus interspecies and some intraspecies crosses, and thus provide a means to directly compare results derived from independent experiments.
Assuntos
Mapeamento Cromossômico , Ciprinodontiformes/genética , Genoma , Hibridização Genética , Repetições de Microssatélites/genética , Animais , Primers do DNA , Eletroforese em Gel de Ágar , Feminino , Isoenzimas , MasculinoRESUMO
The genes encoding 14alpha-sterol demethylases (cyp51A and cyp51B) were analyzed in 12 itraconazole (ITC)-resistant and three ITC-susceptible clinical isolates of Aspergillus fumigatus. Six ITC-resistant strains exhibited a substitution of another amino acid for glycine at position 54, which is located at a very conserved region of the Cyp51A protein. The cyp51A gene from the A. fumigatus wild-type strain (CM-237) was replaced with the mutated cyp51A gene copy of an ITC-resistant strain (AF-72). Two transformants exhibited resistance to ITC, both of which had incorporated the mutated copy of the cyp51A gene.
Assuntos
Antifúngicos/farmacologia , Aspergillus fumigatus/efeitos dos fármacos , Aspergillus fumigatus/genética , Sistema Enzimático do Citocromo P-450/genética , Proteínas Fúngicas/genética , Itraconazol/farmacologia , Mutação Puntual/genética , Substituição de Aminoácidos , Sequência de Bases , Farmacorresistência Fúngica , Eletroporação , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transformação GenéticaRESUMO
Two cyp51-related genes (cyp51A and cyp51B) encoding 14-alpha sterol demethylase-like enzymes were identified in the opportunistic human pathogen Aspergillus fumigatus. PCR amplification using degenerate oligonucleotides based on conserved areas of cytochrome P450 demethylases of other filamentous fungi and yeasts allowed the cloning and sequencing of two different homologue genes in A. fumigatus. Southern analysis confirmed that both genes hybridized to distinct genomic loci and that both are represented as single copies in the genome. Comparison of the deduced Cyp51A and Cyp51B proteins with the CYP51 proteins from Penicillium italicum, Aspergillus nidulans, Erysiphe graminis, Uncinula necator, Botrytis cinerea, Ustilago maydis, Cryptococcus neoformans, Candida albicans, Saccharomyces cerevisiae, Candida tropicalis, and Candida glabrata showed that the percentages of identity of the amino acid sequences (range, 40 to 70%) were high enough to consider Cyp51A and Cyp51B to be members of the fungal CYP51 family. Fragments from both genes were also cloned from other Aspergillus spp. (A. flavus, A. nidulans, and A. terreus). Phylogenetic analysis showed that, at least in the most pathogenic species of Aspergillus, there are two fungal CYP51 proteins. This is the first report of the existence of two homologue genes coding for 14-alpha sterol demethylase in the fungal kingdom. This finding could provide insights into the azole resistance mechanisms operating in fungi. The primers used here may be useful molecular tools for facilitating the cloning of novel 14-alpha sterol demethylase genes in other filamentous fungi.
Assuntos
Aspergillus fumigatus/genética , Aspergillus/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Oxirredutases/genética , Oxirredutases/metabolismo , Sequência de Aminoácidos , Aspergillus/enzimologia , Aspergillus fumigatus/enzimologia , Clonagem Molecular , Sistema Enzimático do Citocromo P-450/química , DNA Fúngico/análise , DNA Fúngico/isolamento & purificação , Humanos , Dados de Sequência Molecular , Oxirredutases/química , Filogenia , Reação em Cadeia da Polimerase , Alinhamento de Sequência , Análise de Sequência de DNA , Esterol 14-DesmetilaseRESUMO
Recently, the methodology that will serve as a basis of the standard for antifungal susceptibility testing of fermentative yeasts of the European Committee on Antibiotic Susceptibility Testing has been described. This procedure employs a spectrophotometric method for both inoculum adjustment and endpoint determination. However, the utilization of a spectrophotometer requires studies for standardization. The present work analyzes the following parameters: (i) accuracy of inoculum preparation, (ii) correlation between optical density and CFU per milliliter, (iii) influence of the wavelength on the endpoint determination, and (iv) influence of the dimethyl sulfoxide concentration on the growth kinetics. The main results can be summarized as follows: (i) inoculum preparation following the methodology recommended by the National Committee for Clinical Laboratory Standards is an exact procedure; (ii) the relationship between optical density and CFU per milliliter is linear (coefficient of determination, r(2) = 0.84); (iii) MICs obtained by means of spectrophotometric readings at different wavelengths are identical (for amphotericin B, an intraclass correlation coefficient of 0.98 was obtained; for fluconazole, the intraclass correlation coefficient was 1); and (iv) a 2% concentration of dimethyl sulfoxide produces a significantly slower and lower growth curve of Candida spp. than other concentrations.
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Anfotericina B/farmacologia , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Fluconazol/farmacologia , Testes de Sensibilidade Microbiana/normas , Candida/classificação , Candida/crescimento & desenvolvimento , Candidíase/microbiologia , Contagem de Colônia Microbiana , Dimetil Sulfóxido/farmacologia , Fungemia/microbiologia , Humanos , Testes de Sensibilidade Microbiana/instrumentação , Testes de Sensibilidade Microbiana/métodos , Espectrofotometria/instrumentação , Espectrofotometria/métodos , Espectrofotometria/normasRESUMO
A major limitation of the National Committee for Clinical Laboratory Standards M27-A methodology is reliable detection of amphotericin B (AMB) resistance. The results obtained by using Iso-Sensitest, a synthetic medium, to detect AMB resistance were analyzed and compared with those obtained with RPMI and antibiotic medium 3 (AM3). The ability to detect AMB resistance with RPMI is not enhanced by using a higher inoculum, glucose supplementation at a final concentration of 20 g/liter, spectrophotometric reading, or 24 h of incubation time. Testing using AM3 and an inoculum of 10(3) CFU/ml detects resistance. Identification of resistant isolates is not improved by glucose supplementation, changes in reading method, or changes in incubation time. However, the use of AM3 as assay medium and an inoculum of 10(5) CFU/ml did not allow detection of AMB resistance. Testing using Iso-Sensitest medium appears to be similar to AM3 in detecting resistance. The most pronounced discrimination is achieved by testing in Iso-Sensitest supplemented with glucose and spectrophotometric reading after 24 h of incubation. The reproducibility of MIC testing was greatest for Iso-Sensitest-based procedures. Use of Iso-Sensitest produces both highly reproducible MICs and reliable identification of AMB-resistant Candida isolates.
Assuntos
Anfotericina B/farmacologia , Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Candida/crescimento & desenvolvimento , Meios de Cultura/classificação , Meios de Cultura/farmacologia , Resistência Microbiana a Medicamentos/fisiologia , Testes de Sensibilidade Microbiana , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
The in vitro activity of flucytosine (5FC) against 1,140 clinical isolates of Candida spp. and Cryptococcus neoformans was evaluated and compared with the activity of amphotericin B, fluconazole and itraconazole. Overall, 87.72% (1,000/1,140) of yeasts were susceptible to 5FC. This agent showed less potent in vitro activity against Candida glabrata, Candida krusei, Candida guilliermondii and Cryptococcus neoformans (MIC90s, 8-16 microg/ml) and intermediate activity or resistance to 6.5% of Candida albicans, 5.1% of Candida tropicalis and 0.8% of Candida parapsilosis strains. Amphotericin B showed potent activity against isolates with an MIC of 5FC > or = 8 microg/ml. A total of 112 of 140 strains that were SFC-intermediate or -resistant showed decreased susceptibility to azoles (P < 0.01).
Assuntos
Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Cryptococcus neoformans/efeitos dos fármacos , Flucitosina/farmacologia , Resistência Microbiana a Medicamentos , Testes de Sensibilidade MicrobianaRESUMO
The in vitro activity of the azasordarin GW 471558 was compared with those of amphotericin B, flucytosine, itraconazole, and ketoconazole against 177 clinical isolates of Candida spp. GW 471558 showed potent activity against Candida albicans, Candida glabrata, and Candida tropicalis, even against isolates with decreased susceptibility to azoles. Candida krusei, Candida parapsilosis, Candida lusitaniae, and Candida guilliermondii are resistant to GW 471558 in vitro (MICs, >128 microg/ml).
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Antifúngicos/farmacologia , Candida/efeitos dos fármacos , Inibidores da Síntese de Proteínas/farmacologia , Candida/isolamento & purificação , Indenos , Testes de Sensibilidade Microbiana , Morfolinas , EspanhaRESUMO
The influences of inoculum size and glucose supplementation on the growth kinetics of 60 Candida spp. clinical isolates (Candida albicans, Candida tropicalis, Candida parapsilosis, Candida glabrata, Candida krusei, and Candida lusitaniae [10 isolates each]) are assessed. The combined influence of growth and reading method (visual or spectrophotometric) on the determination of the MICs of amphotericin B, flucytosine, fluconazole, itraconazole, ketoconazole, and voriconazole is also analyzed, and the MICs are compared with those determined by the National Committee for Clinical Laboratory Standards standard microdilution method (NCCLS document M27-A). Glucose supplementation and inoculum size had a significant influence on the growth cycles of these yeasts, and a statistically significant denser growth (optical density at 540 nm) was seen for both incubation periods, 24 and 48 h (P < 0.01). A longer exponential phase and shorter lag phase were also observed. The A540 values at 24 h of incubation with medium containing glucose and an inoculum of 10(5) CFU/ml were >0.4 U for all species, with the exception of that for C. parapsilosis (A540 = 0.26 +/- 0.025). The MICs at 24 h determined by testing with 2% glucose and an inoculum of 10(5) CFU/ml showed the strongest agreement (96.83%) with MICs determined by the reference method. MICs were not falsely elevated, and good correlation indexes were obtained. The reproducibility of results with this medium-inoculum combination was high (intraclass correlation coefficient, 0.955). The best agreement and reproducibility of results for spectrophotometric readings were achieved with endpoints of 50% growth inhibition for flucytosine and azoles and 95% for amphotericin B. Supplementation of test media with glucose and an inoculum size of 10(5) CFU/ml yielded a reproducible technique that shows elevated agreement with the reference procedures and a shorter incubation period for obtaining reliable MIC determinations. The spectrophotometric method offers an advantage over the visual method by providing a more objective and automated MIC determination.
Assuntos
Candida/crescimento & desenvolvimento , Glucose , Testes de Sensibilidade Microbiana , Candida/efeitos dos fármacos , Candida/isolamento & purificação , Candida albicans/efeitos dos fármacos , Candida albicans/crescimento & desenvolvimento , Candidíase/diagnóstico , Candidíase/microbiologia , Meios de Cultura , Humanos , Cinética , Micologia/métodos , Reprodutibilidade dos Testes , Fatores de TempoRESUMO
The ability of nine clinical isolates of Candida species (three C. albicans, three C. tropicalis and three C. parapsilosis) to colonize and invade the gastrointestinal (GI) tract of adult male CD-1 (ICR) mice was determined. The effect of dietary tetracycline plus glucose supplementation on colonization was evaluated. Strains were intragastrically inoculated. Tetracycline and glucose altered substantially aerobic flora, especially streptococci (average fall 1.1 +/-0.3 log(10) CFU/g, p<0.01 by the Student's t test). At two weeks after oral challenge, sustained and high colonization of GI tract by Candida (mean 5,28 +/- 0.18 log(10) CFU/g, p<0.01) was achieved in all mice receiving glucose-tetracycline supplementation, excepting in animals inoculated with one of C. tropicalis isolates. Histologic sections of the stomachs revealed multiple intraepithelial micro-abscesses associated with hyphae in the region of the cardial-atrium fold. Under immunosuppression, systemic spread of C. albicans and C. tropicalis was observed in 62% and 24% of animals receiving dietary supplementation respectively. Dissemination was not noted for C. parapsilosis isolates. We have developed a simple and inexpensive murine model of sustained colonization of GI tract. This model could be useful for analyzing prophylaxis, treatment and diagnosis of systemic Candida infections and for evaluating virulence of strains.