Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 11 de 11
Filtrar
1.
AJNR Am J Neuroradiol ; 42(1): 194-200, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33431505

RESUMO

BACKGROUND AND PURPOSE: Little is known about microstructural development of cerebellar white matter in vivo. This study aimed to investigate developmental changes of the cerebellar peduncles in second- and third-trimester healthy fetuses using motion-corrected DTI and tractography. MATERIALS AND METHODS: 3T data of 81 healthy fetuses were reviewed. Structural imaging consisted of multiplanar T2-single-shot sequences; DTI consisted of a series of 12-direction diffusion. A robust motion-tracked section-to-volume registration algorithm reconstructed images. ROI-based deterministic tractography was performed using anatomic landmarks described in postnatal tractography. Asymmetry was evaluated qualitatively with a perceived difference of >25% between sides. Linear regression evaluated gestational age as a predictor of tract volume, ADC, and fractional anisotropy. RESULTS: Twenty-four cases were excluded due to low-quality reconstructions. Fifty-eight fetuses with a median gestational age of 30.6 weeks (interquartile range, 7 weeks) were analyzed. The superior cerebellar peduncle was identified in 39 subjects (69%), and it was symmetric in 15 (38%). The middle cerebellar peduncle was identified in all subjects and appeared symmetric; in 13 subjects (22%), two distinct subcomponents were identified. The inferior cerebellar peduncle was not found in any subject. There was a significant increase in volume for the superior cerebellar peduncle and middle cerebellar peduncle (both, P < .05), an increase in fractional anisotropy (both, P < .001), and a decrease in ADC (both, P < .001) with gestational age. The middle cerebellar peduncle had higher volume (P < .001) and fractional anisotropy (P = .002) and lower ADC (P < .001) than the superior cerebellar peduncle after controlling for gestational age. CONCLUSIONS: A robust motion-tracked section-to-volume registration algorithm enabled deterministic tractography of the superior cerebellar peduncle and middle cerebellar peduncle in vivo and allowed characterization of developmental changes.


Assuntos
Algoritmos , Cerebelo/embriologia , Imagem de Tensor de Difusão/métodos , Processamento de Imagem Assistida por Computador/métodos , Neurogênese , Feminino , Feto , Humanos , Masculino , Neurogênese/fisiologia , Gravidez , Terceiro Trimestre da Gravidez , Estudos Retrospectivos
2.
AJNR Am J Neuroradiol ; 41(8): 1525-1531, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32646947

RESUMO

BACKGROUND AND PURPOSE: Brain MRI of newborns with congenital heart disease show signs of immaturity relative to healthy controls. Our aim was to determine whether the semiquantitative fetal total maturation score can detect abnormalities in brain maturation in fetuses with congenital heart disease in the second and third trimesters. MATERIALS AND METHODS: We analyzed data from a prospective study of fetuses with and without congenital heart disease who underwent fetal MR imaging at 25-35 weeks' gestation. Two independent neuroradiologists blinded to the clinical data reviewed and scored all images using the fetal total maturation score. Interrater reliability was evaluated by the intraclass correlation coefficient using the individual reader scores, which were also used to calculate an average score for each subject. Comparisons of the average and individual reader scores between affected and control fetuses and relationships with clinical variables were evaluated using multivariable linear regression. RESULTS: Data from 69 subjects (48 cardiac, 21 controls) were included. High concordance was observed between readers with an intraclass correlation coefficient of 0.98 (95% CI, 0.97-0.99). The affected group had significantly lower fetal total maturation scores than the control group (ß-estimate, -0.9 [95% CI, -1.5 to -0.4], P = .002), adjusting for gestational age and sex. Averaged fetal total maturation, germinal matrix, myelination, and superior temporal sulcus scores were significantly delayed in fetuses with congenital heart disease versus controls (P < .05 for each). The fetal total maturation score was not significantly associated with any cardiac, anatomic, or physiologic variables. CONCLUSIONS: The fetal total maturation score is sensitive to differences in brain maturation between fetuses with isolated congenital heart disease and healthy controls.


Assuntos
Encéfalo/anormalidades , Encéfalo/embriologia , Feto/diagnóstico por imagem , Feto/embriologia , Cardiopatias Congênitas/complicações , Adulto , Encéfalo/diagnóstico por imagem , Feminino , Humanos , Interpretação de Imagem Assistida por Computador/métodos , Recém-Nascido , Imageamento por Ressonância Magnética/métodos , Masculino , Gravidez , Diagnóstico Pré-Natal/métodos , Estudos Prospectivos , Reprodutibilidade dos Testes
3.
Ann Ig ; 32(1): 72-80, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31713579

RESUMO

BACKGROUND: Clostridioides difficile a Gram-positive, obliged anaerobic, rod-shaped spore-former bacterium, causes a wide spectrum of diseases, ranging from mild, self-limiting diarrhoea to serious diarrhea. Chitosan, a natural polysaccharide, is largely known for its activity against a wide range of microorganisms. Chitosan, in the form of nanofibrils (nanofibrilated chitosan), consists of separated fibers which can be suspended easily in aqueous media. STUDY DESIGN: This paper, for the first time, aims to evaluate the antimicrobial activity of chitosan nanofibers against C. difficile isolates. METHODS: Chitosan nanofibers were characterized through scanning electron microscopy and atomic force microscopy. Minimum inhibitory concentration and minimum bactericidal concentration of chitosan nanofibers against toxigenic C. difficile isolates (with resistance gene: ermB, tetM and tetW) was determined by the standard broth microdilution method. RESULTS: The Miniumum Inhibitory Concentration of chitosan nanofibers for two toxigenic isolates with resistance genes ermB, tetM and tetW, two toxigenic isolates ermB+ tetM+ and the standard strain ATCC 700057 was similar and equal to 0.25 mg/mL. The minimum bactericidal concentration for all isolates was 0.5 mg/mL. CONCLUSIONS: The results demonstrated that chitosan nanofibers exhibit potent antimicrobial activities against multiple toxigenic C. difficile isolates, and the antibacterial effect of chitosan nanofibers against C. difficile isolates with ermB, tetM and tetW resistance genes indicates that interfering with the synthesis of proteins is not the mechanism of action of chitosan nanofibers.


Assuntos
Antibacterianos , Quitosana , Clostridioides difficile , Nanofibras , Proteínas de Bactérias/genética , Toxinas Bacterianas/genética , Clostridioides difficile/genética , Farmacorresistência Bacteriana/genética , Fezes/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Nanofibras/ultraestrutura
4.
Ann Ig ; 31(2): 148-155, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30714612

RESUMO

INTRODUCTION: We aimed to determine the distribution of Phenol-soluble modulin-mec (psm-mec) gene and its relationship with biofilm formation in clinical methicillin-resistant S. aureus (MRSA). METHODS: In a descriptive study, a total of 94 cefoxitin-resistant S. aureus isolates were collected from patients and tested for antibiotic susceptibility testing, multiplex polymerase chain reaction (MPCR) for detection of mecA and pvl genes, PCR for detection of psm-mec gene and SCCmec typing of psm-mec and pvl-positive isolates. Furthermore, isolates were tested by microtiter plate method for biofilm formation assay. RESULTS: Multiplex PCR for detection of mecA and pvl genes was performed for all cefoxitin-resistant isolates. The mecA gene was found in 92 (97.9%) isolates but none of the isolates carried the pvl gene. Sixty-five (69.1%) isolates harbored psm-mec genes and 95.4% of these isolates belong to SCCmec type III. Statistical analysis showed a significant difference between the presence or absence of psm-mec gene and biofilm production (P<0.001). CONCLUSION: In this study, more than half of the MRSA strains harbored psm-mec gene and almost one-fifth of them produced strong biofilm. Since the strains with strong biofilm formation have more antibiotic resistance and cause the long-lasting infection, for the suitable treatment of hospitalized patients with this kind of MRSA strains, we should be paid more attention to these strains.


Assuntos
Antibacterianos/farmacologia , Toxinas Bacterianas/genética , Biofilmes , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Adulto , Idoso , Farmacorresistência Bacteriana Múltipla , Feminino , Humanos , Masculino , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase Multiplex , Prevalência , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
5.
Ann Ig ; 30(5): 391-400, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30062367

RESUMO

BACKGROUND: S. aureus strains, with the capability of producing toxic shock syndrome toxin-1 (TSST-1), are more likely to cause complicated infections. However, due to lack of comprehensive local data on the prevalence of TSST-1, we aimed to determine the prevalence of TSST-1 harboring S. aureus isolates in Iran. METHODS: A systematic search was performed by using PubMed and Scopus databases from papers published by Iranian authors from January 2000 to the end of March 2017. Then, 10 publications which were matched with inclusion criteria were selected for data extraction and analysis by Comprehensive Meta-Analysis Software. RESULTS: The overall prevalence of TSST-1 carrying S. aureus in Iran was 21.3% (95% CI: 7.9%-46.1%), ranging from 0% to 68%. Moreover, from the included studies, the pooled prevalence of TSST-1 producing MRSA isolates was estimated to be 25.2% (95% CI: 13.3%-42.5%), ranging from 0% to 69.8%. From those studies which showed the distribution of toxin-harboring S. aureus it was found that the skin and soft tissue, respiratory and bloodstream infections were the common sites of TSST-1 harboring S. aureus. CONCLUSIONS: In summary, it seems that emergence of MRSA strains leads to higher prevalence of TSST-1 carrying strains in the north of Iran. However, further research is required to elucidate the interplay between the outcome of diseases and TSST-1 producing strains, especially in our country.


Assuntos
Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus/isolamento & purificação , Bacteriemia/epidemiologia , Bacteriemia/microbiologia , Toxinas Bacterianas/biossíntese , Enterotoxinas/biossíntese , Humanos , Irã (Geográfico)/epidemiologia , Prevalência , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/microbiologia , Dermatopatias Bacterianas/epidemiologia , Dermatopatias Bacterianas/microbiologia , Infecções Estafilocócicas/microbiologia , Superantígenos/biossíntese
6.
J Biomech ; 49(13): 2946-2952, 2016 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-27452877

RESUMO

Spinal posture is a crucial input in biomechanical models and an essential factor in ergonomics investigations to evaluate risk of low back injury. In vivo measurement of spinal posture through the common motion capture techniques is limited to equipped laboratories and thus impractical for workplace applications. Posture prediction models are therefore considered indispensable tools. This study aims to investigate the capability of artificial neural networks (ANNs) in predicting the three-dimensional posture of the spine (S1, T12 and T1 orientations) in various activities. Two ANNs were trained and tested using measurements from spinal postures of 40 male subjects by an inertial tracking device in various static reaching and lifting (of 5kg) activities. Inputs of each ANN were position of the hand load and body height, while outputs were rotations of the three foregoing segments relative to their initial orientation in the neutral upright posture. Effect of posture prediction errors on the estimated spinal loads in symmetric reaching activities was also investigated using a biomechanical model. Results indicated that both trained ANNs could generate outputs (three-dimensional orientations of the segments) from novel sets of inputs that were not included in the training processes (root-mean-squared-error (RMSE)<11° and coefficient-of-determination (R2)>0.95). A graphic user interface was designed and made available to facilitate use of the ANNs. The difference between the mean of each measured angle in a reaching task and the corresponding angle in a lifting task remained smaller than 8°. Spinal loads estimated by the biomechanical model based on the predicted postures were on average different by < 12% from those estimated based on the exact measured postures (RMSE=173 and 35N for the L5-S1 compression and shear loads, respectively).


Assuntos
Remoção , Redes Neurais de Computação , Coluna Vertebral/fisiologia , Lesões nas Costas/prevenção & controle , Fenômenos Biomecânicos , Simulação por Computador , Humanos , Imageamento Tridimensional , Masculino , Modelos Anatômicos , Postura , Coluna Vertebral/anatomia & histologia , Interface Usuário-Computador , Suporte de Carga , Adulto Jovem
7.
J Anim Physiol Anim Nutr (Berl) ; 100(4): 623-8, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26608665

RESUMO

The objective of this study was to evaluate the effects of increasing garlic powder and monensin supplementation on feed intake, nutrient digestibility, growth performance and blood metabolites of growing calves. Forty Holstein calves (BW = 100 ± 11 kg) were randomly assigned to four dietary treatments (n = 10) in a complete randomized design. Experimental treatments consisted of the following: (i) basal diet (control), (ii) basal diet supplemented with 0.0003% of dietary dry matter (DM) sodium monensin, (iii) low level of garlic powder (Low-GAR; 0.5% of dietary DM) and (iv) high level of garlic powder (High-GAR; 1% of dietary DM). DM intake (DMI) and DM digestibility were (p < 0.05) decreased by High-GAR. However, calves supplemented with Low-GAR had a similar DMI to the control calves and similar DM digestibility to the control and monensin groups. The digestibility of other nutrients were not affected by the treatments. Although supplementing monensin relative to Low-GAR increased the DMI (p < 0.05), average daily gain was similar between Low-GAR and monensin supplemented calves, which were higher than the control and High-GAR groups (p < 0.05). As a result, feed conversion ratio was improved in the Low-GAR group versus other treatment groups (p < 0.05). Administrating garlic powder decreased the blood low-density lipoprotein (LDL) and non-esterified fatty acids (p < 0.05) without affecting the blood triglyceride, high-density lipoprotein and beta-hydroxybutyric acid concentrations. In conclusion, the calves fed the Low-GAR showed an improved FCR and blood metabolites without changing the DMI and nutrient digestibility. It suggests that garlic powder could be used as an alternative to monensin for growing calves under the current feeding conditions.


Assuntos
Bovinos/fisiologia , Dieta/veterinária , Digestão/efeitos dos fármacos , Alho , Monensin/farmacologia , Ração Animal/análise , Fenômenos Fisiológicos da Nutrição Animal , Animais , Bovinos/sangue , Digestão/fisiologia , Ingestão de Alimentos , Concentração de Íons de Hidrogênio , Monensin/administração & dosagem , Rúmen/fisiologia
8.
Cereb Cortex ; 23(12): 2932-43, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22977063

RESUMO

Neurologic impairment is a major complication of complex congenital heart disease (CHD). A growing body of evidence suggests that neurologic dysfunction may be present in a significant proportion of this high-risk population in the early newborn period prior to surgical interventions. We recently provided the first evidence that brain growth impairment in fetuses with complex CHD has its origins in utero. Here, we extend these observations by characterizing global and regional brain development in fetuses with hypoplastic left heart syndrome (HLHS), one of the most severe forms of CHD. Using advanced magnetic resonance imaging techniques, we compared in vivo brain growth in 18 fetuses with HLHS and 30 control fetuses from 25.4-37.0 weeks of gestation. Our findings demonstrate a progressive third trimester fall-off in cortical gray and white matter volumes (P < 0.001), and subcortical gray matter (P < 0.05) in fetuses with HLHS. Significant delays in cortical gyrification were also evident in HLHS fetuses (P < 0.001). In the HLHS fetus, local cortical folding delays were detected as early as 25 weeks in the frontal, parietal, calcarine, temporal, and collateral regions and appear to precede volumetric brain growth disturbances, which may be an early marker of elevated risk for third trimester brain growth failure.


Assuntos
Córtex Cerebral/anormalidades , Feto/anormalidades , Síndrome do Coração Esquerdo Hipoplásico/patologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Gravidez
9.
Int J Prev Med ; 3(7): 466-70, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22891147

RESUMO

INTRODUCTION: This study aimed to evaluate the effectiveness of exercise and token-behavior therapy on the negative symptoms of schizophrenic patients. OBJECTIVE: Comparison of the effectiveness of exercise and token-behavior therapy on the negative symptoms of schizophrenic patients. METHODS: This research was a randomized controlled clinical trial that was done on 45 schizophrenic patients, hospitalized in Rasht, Iran. Through systematic random allocation, the samples were placed in one control and two intervention groups, 15 patients in each. To assess the negative symptoms, the scale for the assessment of negative symptoms (SANS) was used. The effect of the interventions used (exercise and token-behavior therapy) was studied by completing the relevant checklists before and after using the interventions, and then, by comparing it with that of the studied control group. In order to analyze the collected data, one way ANOVA and Bonferroni's test and SPSS software were used. RESULTS: Analyses showed that the token reinforcement approach was highly and significantly more effective than exercise for reducing the negative symptoms in schizophrenic patients (-36 ± 7 vs. -21 ± 8, respectively; P<0.001). Exercise was also shown to have a highly significant advantage over no therapy, in controls, to improve the negative symptoms in schizophrenic patients (-25 ± 8 vs. 0.2 ± 1.08, respectively; P<0.001). CONCLUSION: Both exercise and token-behavior therapies, along with drug treatment, are very effective in reducing the negative symptoms of schizophrenia; but the impact of token therapy issignificantly higher.

10.
Artigo em Inglês | MEDLINE | ID: mdl-22255750

RESUMO

This paper presents a statistical image modeling approach based on Markov random field to synthesize cervical tissue second harmonic generation (SHG) images. Binary images representing fiber and pore areas of the cervix tissue are first obtained from SHG images using an image processing pipeline consisting of noise removal, contrast enhancement and optimal thresholding. These binary images are modeled using a Markov random field whose parameters are estimated via the least squares method. The parameters are then used to synthesize fiber and pore areas of cervical tissue in the form of binary images. The effectiveness of the synthesis is demonstrated by reporting the classification outcome for two classes of cervical SHG images collected from mice at two different stages of normal pregnancy. The developed synthesis allows generation of realistic fiber and pore area binary images for cervical tissue studies.


Assuntos
Colo do Útero/patologia , Diagnóstico por Imagem/métodos , Algoritmos , Animais , Feminino , Humanos , Processamento de Imagem Assistida por Computador , Cadeias de Markov , Camundongos , Modelos Animais , Modelos Estatísticos , Distribuição Normal , Porosidade , Gravidez , Prenhez , Probabilidade
11.
Biomed Pharmacother ; 56(4): 169-72, 2002 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-12109808

RESUMO

Transaminase activity and serum total protein level were investigated in adult rats after oral treating with sodium fluoride at three doses, 10, 20 and 30 mg/kg daily for 90 days. After 90 days, the average total serum protein level of the rats in the treatment group decreased significantly compared with that in the control [1.9 +/- 0.1 (mean +/- S.D., n = 140) vs. 3.1 +/- 0.2] mg/dl, P< 0.05. Serum transaminase activity in the treatment group increased compared with that in the control [5.3 +/- 0.4 (mean +/- S.D., n = 140) vs. 3.2 +/- 0.3] micromol/min per ml, P < 0.05.


Assuntos
Proteínas Sanguíneas/metabolismo , Fluoreto de Sódio/farmacologia , Transaminases/sangue , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Relação Dose-Resposta a Droga , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Ratos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...