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1.
J Dairy Sci ; 2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38608958

RESUMO

This study is aimed at investigating the effects of dietary supplementation with Artemisia ordosica crude polysaccharides (AOCP) on lactation performance, antioxidant status, and immune status of lactating donkeys and analyzing rectal microbiomes and serum metabolomes. Fourteen lactating Dezhou donkeys with similar age (6.16 ± 0.67 years of BW ± SD), weight (250.06 ± 25.18 kg), days in milk (39.11 ± 7.42 d), and averaged parity of 3 were randomly allocated into 2 treatments: a control group (CON, basal diet) and an AOCP group (AOCP, basal diet with 1.0 g/kg DM AOCP). Ten weeks were allotted for the experiment, 2 weeks for adaptation, and 8 weeks for collecting data and samples. The results showed that supplementation of donkey diets with AOCP increased lactation performance, including dry matter intake, milking yield, estimated milk yield, solids-corrected milk, energy-corrected milk, milk fat yield, milk protein yield, milk lactose yield, milk total solids yield, and milk solid not fat yield. The digestibility of dry matter, crude protein, acid detergent fiber, and neutral detergent fiber was increased in the AOCP group compared with the CON group. The AOCP group increased the concentrations of immunoglobulin A, immunoglobulin G, and immunoglobulin M, the activities of the superoxide dismutase, catalase and total antioxidant capacity in the serum. AOCP decreased the concentrations of tumor necrosis factor-α, nitric oxide, reactive oxygen species, and malondialdehyde in the serum. Compared with the CON group, AOCP increased propionate, butyrate, isovalerate, and total VFA concentrations in rectal feces (P < 0.05). The addition of AOCP to increased diversity (Shannon index) and altered structure of the rectal microflora. As a result of AOCP supplementation, there has been a significant improvement in the colonization of beneficial bacteria, including Lactobacillus, Unclassified_f_Prevotellacea, Ruminococcus, and Fibrobacter genera. In contrast, a decrease in the colonization of the Clostridium_sensu_stricto_1 bacterial genus and other pathogenic bacteria was observed. Meanwhile, metabolomics analysis found that AOCP supplementation upregulated metabolites L-tyrosine content while downregulating 9(S)-HODE, choline, sucrose, LysoPC (18:0), LysoPC (18:1(9Z), and LysoPC (20:2(11Z,14Z)) concentrations. These altered metabolites were involved in the PPAR signaling pathway, prolactin signaling pathway, glycerophospholipid metabolism, carbohydrate digestion and absorption, and tyrosine metabolism pathways, which were mainly related to antioxidant capacity, immune responses, and protein metabolism in the lactating donkeys. As a consequence of feeding AOCP diets, beneficial bacteria were abundant, and antioxidant and protein metabolism-related pathways were enriched, which may enhance lactation performance in donkeys. Therefore, supplementing AOCP diets is a desirable dietary strategy to improve donkey health and lactation performance.

2.
Eur Rev Med Pharmacol Sci ; 24(13): 7454-7461, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32706085

RESUMO

OBJECTIVE: To develop a promising approach for tumor immunotherapy with G250 antigen-based DNA vaccine and to investigate its anti-tumor response in mice with renal cell carcinoma. MATERIALS AND METHODS: G250 derived from human, monkey and mouse were prepared by PCR. The heterogeneous chimeric G250 gene was obtained by integrating different gene fragments of three species. Then, the chimeric G250 was inserted into a eukaryotic expression plasmid pVAX1-IRES-GM/B7 to obtain DNA vaccine (named pVAX1-tG250-GM/B7) which could express chimeric G250 antigen and immune adjuvants simultaneously. By transfecting into Cos7 cells, the expression of chimeric G250 antigen was tested using flow cytometry and immunofluorescence assay. The immunological response and protection against tumor were evaluated in vivo. RESULTS: Recombinant plasmid DNA vaccine was constructed successfully through identification of PCR and gene sequencing. The chimeric G250 antigen was well expressed in Cos7 cells. A strong immune response can be detected through ELISPOT and ELISA induced by pVAX1-tG250-GM/B7. The mice vaccinated with pVAX1-tG250-GM/B7, balb/c showed significant inhibition of tumor and a longer time of survival compared with control group. CONCLUSIONS: The experimental results of this study exhibited that the DNA vaccine based on heterogeneous chimeric antigen can produce efficient anti-tumor effect in vivo and they represent a promising strategy for tumor immunotherapy.


Assuntos
Antígenos de Neoplasias/farmacologia , Vacinas Anticâncer/farmacologia , Anidrase Carbônica IX/farmacologia , Carcinoma de Células Renais/tratamento farmacológico , Neoplasias Renais/tratamento farmacológico , Animais , Antígenos de Neoplasias/genética , Antígenos de Neoplasias/metabolismo , Células COS , Vacinas Anticâncer/genética , Vacinas Anticâncer/metabolismo , Anidrase Carbônica IX/genética , Anidrase Carbônica IX/metabolismo , Carcinoma de Células Renais/imunologia , Carcinoma de Células Renais/metabolismo , Carcinoma de Células Renais/patologia , Linhagem Celular Tumoral , Chlorocebus aethiops , Citocinas/metabolismo , Feminino , Haplorrinos , Imunogenicidade da Vacina , Imunoglobulina G/sangue , Neoplasias Renais/imunologia , Neoplasias Renais/metabolismo , Neoplasias Renais/patologia , Camundongos , Camundongos Endogâmicos BALB C , Carga Tumoral/efeitos dos fármacos , Vacinação , Vacinas de DNA/genética , Vacinas de DNA/metabolismo , Vacinas de DNA/farmacologia
3.
Clin Radiol ; 72(9): 797.e11-797.e16, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28477959

RESUMO

AIM: To investigate the dose-length product (DLP) during intracranial computed tomography angiography (CTA) using a patient-specific contrast formula. MATERIALS AND METHODS: Intracranial CTA was performed on 120 patients using 64-channel CT. Patients were subjected in equal numbers to one of two acquisitions/contrast medium protocols. Protocol A, consisted of 80 ml contrast medium and protocol B, involved a novel contrast medium formula. In each protocol, contrast medium and saline were injected at a flow rate of 4.5 ml/s. The DLP and contrast volume (CV) were measured between each protocol and the data obtained were compared using two-tailed independent t-test. RESULTS: Mean arterial vessel attenuation was up to 56% (p<0.01) higher using protocol B compared with A. In the venous system, the mean vessel attenuation was significantly lower in protocol B than A with a maximum reduction of 93% (p<0.001). The mean CV was significantly lower in protocol B (53±10 ml) compared to A (80±1 ml, p<0.001). The scan time was equal in each protocol (B, 4.22±1.2 seconds; A, 4.01±1.3 seconds). A significant reduction in mean DLP was demonstrated in protocol B (3.99±0.22 mSv) compared to A (4.74±0.22 mSv; p=0.02). CONCLUSION: A significant reduction in CV and DLP during intracranial CTA can be achieved when employing a patient-specific contrast medium formula.


Assuntos
Circulação Cerebrovascular , Angiografia por Tomografia Computadorizada/métodos , Meios de Contraste/administração & dosagem , Iohexol/análogos & derivados , Doses de Radiação , Acidente Vascular Cerebral/diagnóstico por imagem , Feminino , Humanos , Iohexol/administração & dosagem , Masculino , Estudos Prospectivos , Interpretação de Imagem Radiográfica Assistida por Computador
4.
Panminerva Med ; 59(1): 97-106, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27636117

RESUMO

INTRODUCTIONː The prognostic value of c-Met in patients with esophageal cancer (EC) remains inconsistent and controversial. Our study aims to clarify the correlation between c-Met overexpression and clinical outcome in EC patients. EVIDENCE ACQUISITIONː We performed a comprehensive search of EMBASE, PubMed, Web of Science, Chinese National Knowledge Infrastructure (CNKI) and Chinese Biomedical Database (CBM) (from inception to May 1, 2016) for published literature regarding the potential association between c-Met overexpression and clinical outcome in EC patients. A fixed-effects or random-effects model according to heterogeneity was applied to calculate the pooled hazard ratios (HRs) with 95% confidence intervals (CIs) for overall survival (OS), disease-free survival (DFS) and disease-specific survival (DSS). EVIDENCE SYNTHESISː Nine eligible studies totaling 1062 patients were identified in this meta-analysis. C-Met overexpression was significantly associated with shorter OS (HR: 2.04, 95% CI: 1.66-2.52, P<0.001) and DSS (HR: 3.03, 95% CI: 2.04-4.48, P<0.001) in patients with EC. However, no significant relationship between high expression of c-Met and DFS that was found (HR: 1.81, 95% CI: 0.77-4.26, P=0.176). For OS, similar associations were demonstrated in either esophageal squamous cell carcinoma (ESCC) (HR: 2.17, 95% CI: 1.62-2.90, P<0.001) or esophageal adenocarcinoma (EAC) (HR: 1.92, 95% CI: 1.42-2.59, P<0.001). Additionally, further subgroup analyses according to publication year, ethnicity, the sample size, and statistical methodology all revealed a significant association between high expression of c-Met and OS in patients with EC. CONCLUSIONSː The current evidence indicated that c-Met overexpression is significantly associated with a poorer prognosis in EC. C-Met may serve as a potential novel prognostic biomarker for EC patients.


Assuntos
Adenocarcinoma/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Neoplasias Esofágicas/diagnóstico , Proteínas Proto-Oncogênicas c-met/metabolismo , Adenocarcinoma/metabolismo , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/metabolismo , Intervalo Livre de Doença , Neoplasias Esofágicas/metabolismo , Carcinoma de Células Escamosas do Esôfago , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Prognóstico , Resultado do Tratamento
5.
Genet Mol Res ; 13(3): 6113-25, 2014 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-25117370

RESUMO

DNA vaccination has been studied intensively as a potential vaccine technology. We evaluated the effect of an attenuated Salmonella choleraesuis-mediated inhibin DNA vaccine in rats. First, 15 rats were treated with different doses of an inhibin vaccine to evaluate vaccine safety. Next, 30 rats were divided into 3 groups and injected intramuscularly with the inhibin vaccine two (T1) or three times (T2) or with control bacteria (Con) at 4-week intervals. The inhibin antibody levels increased [positive/negative well (P/N) value: T1 vs Con = 2.39 ± 0.01 vs 1.08 ± 0.1; T2 vs Con = 2.36 ± 0.1 vs 1.08 ± 0.1, P < 0.05] at week 2 and were maintained at a high level in T1 and T2 until week 8, although a small decrease in T2 was observed at week 10. Rats in the T1 group showed more corpora lutea compared with the Con group (10.50 ± 0.87 vs 7.4 ± 0.51, P < 0.05). Estradiol (0.439 ± 0.052 vs 0.719 ± 0.063 ng/mL, P < 0.05) and progesterone (1.315 ± 0.2 vs 0.737 ± 0.11 ng/mL, P < 0.05) levels differed significantly at metestrus after week 10 between rats in the T1 and Con groups. However, there were no significant differences in body, ovary, uterus weights, or pathological signs in the ovaries after immunization, indicating that this vaccine is safe. In conclusion, the attenuated S. choleraesuis-mediated inhibin vaccine may be an alternative to naked inhibin plasmids for stimulating ovarian follicular development to increase the ovulation rate in rats.


Assuntos
Inibinas/genética , Inibinas/imunologia , Salmonella/genética , Vacinas Atenuadas/imunologia , Vacinas de DNA/imunologia , Animais , Anticorpos/sangue , Anticorpos/imunologia , Estradiol/sangue , Feminino , Imunização , Folículo Ovariano/imunologia , Folículo Ovariano/patologia , Ovulação , Progesterona/sangue , Ratos , Vacinas Atenuadas/administração & dosagem , Vacinas Atenuadas/efeitos adversos , Vacinas de DNA/administração & dosagem , Vacinas de DNA/efeitos adversos
6.
AJNR Am J Neuroradiol ; 35(8): 1527-32, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24722305

RESUMO

BACKGROUND AND PURPOSE: High-resolution MR imaging is an emerging tool for evaluating intracranial artery disease. It has an advantage of defining vessel wall characteristics of intracranial vascular diseases. We investigated high-resolution MR imaging arterial wall characteristics of CNS vasculitis and reversible cerebral vasoconstriction syndrome to determine wall pattern changes during a follow-up period. MATERIALS AND METHODS: We retrospectively reviewed 3T-high-resolution MR imaging vessel wall studies performed on 26 patients with a confirmed diagnosis of CNS vasculitis and reversible cerebral vasoconstriction syndrome during a follow-up period. Vessel wall imaging protocol included black-blood contrast-enhanced T1-weighted sequences with fat suppression and a saturation band, and time-of-flight MRA of the circle of Willis. Vessel wall characteristics including enhancement, wall thickening, and lumen narrowing were collected. RESULTS: Thirteen patients with CNS vasculitis and 13 patients with reversible cerebral vasoconstriction syndrome were included. In the CNS vasculitis group, 9 patients showed smooth, concentric wall enhancement and thickening; 3 patients had smooth, eccentric wall enhancement and thickening; and 1 patient was without wall enhancement and thickening. Six of 13 patients had follow-up imaging; 4 patients showed stable smooth, concentric enhancement and thickening; and 2 patients had resoluton of initial imaging findings. In the reversible cerebral vasoconstriction syndrome group, 10 patients showed diffuse, uniform wall thickening with negligible-to-mild enhancement. Nine patients had follow-up imaging, with 8 patients showing complete resolution of the initial findings. CONCLUSIONS: Postgadolinium 3T-high-resolution MR imaging appears to be a feasible tool in differentiating vessel wall patterns of CNS vasculitis and reversible cerebral vasoconstriction syndrome changes during a follow-up period.


Assuntos
Transtornos Cerebrovasculares/patologia , Imageamento por Ressonância Magnética/métodos , Vasculite do Sistema Nervoso Central/patologia , Vasoconstrição , Adulto , Idoso , Feminino , Humanos , Angiografia por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
7.
Rev Med Brux ; 32(4): 205-9, 2011 Sep.
Artigo em Francês | MEDLINE | ID: mdl-22034746

RESUMO

The purpose of this article is to improve the general practitioner's knowledge about nevi and to teach how to evaluate the risk of a lesion during a medical visit. The most frequent kind of nevi will be defined, as well as their transformation risk. Different melanoma risk factors and the semiology that can alert the practitioner will be defined. A set of the most frequently asked questions about nevi will be answered.


Assuntos
Nevo/patologia , Dermoscopia , Medicina Geral , Humanos , Nevo/etiologia
8.
Singapore Med J ; 52(8): 620-30, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21879224

RESUMO

The brain is extremely susceptible to focal ischaemia. Following vascular occlusion, a core of severely damaged brain tissue develops, surrounded by an ischaemic penumbra. This potentially-salvageable penumbra may be estimated by advanced neuroimaging techniques, particularly by diffusion-perfusion mismatch. Clinical trials have demonstrated the efficacy of intravenous thrombolysis within three hours of onset of ischaemic stroke in reducing short-term disability. Recanalisation is enhanced by intra-arterial thrombolysis, sonothrombolysis and clot-retrieval devices. Occasionally, reperfusion injury may lead to clinical deterioration. The search continues for effective neuroprotectants. Brain perfusion needs to be maintained through blood and intracranial pressure management. Hemicraniectomy for 'malignant' cerebral oedema reduces death and disability. Elevated glucose should be controlled and hypoxia alleviated. Public education of symptoms and the need for immediate presentation to a medical facility is needed. Stroke unit care reduces death and disability with little increase in cost. Current evidence supports urgent efforts to resuscitate the brain after stroke.


Assuntos
Isquemia Encefálica/terapia , Acidente Vascular Cerebral/terapia , Isquemia Encefálica/complicações , Isquemia Encefálica/diagnóstico , Ensaios Clínicos como Assunto , Humanos , Monitorização Fisiológica , Ressuscitação , Singapura , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/diagnóstico , Terapia Trombolítica
9.
Neuroradiol J ; 23(3): 269-78, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24148583

RESUMO

In vivo proton MR spectroscopy ((1)H-MRS) can non-invasively provide biochemical information at the same examination as conventional magnetic resonance imaging (MRI). Lipid resonance (0.9-1.5 ppm) is a marker of cell membrane breakdown and tissue necrosis, but its diagnostic significance has not been well described. We retrospectively analyzed spectra to study the different pathological conditions in patients with abnormal lipid resonance. All patients with neurological diseases showing lipid resonance on (1)H-MRS (1.5T) in a tertiary hospital over two years were retrospectively analyzed. (1)H-MRS was performed using the single voxel PRESS technique (TR/TE=3000/144 ms, eight excitations). Spectra were analysed for the presence of NAA (2.0 ppm), creatine (3.0 ppm), choline (3.2 ppm), acetate (1.92 ppm), succinate (2.4 ppm), cytosolic amino acids (0.9 ppm), lactate (1.3 ppm) and lipid (0.9-1.5 ppm) peaks. Ninety-two spectra from 69 patients (38 males, 31 females; aged 9 to 89 years) were analyzed. The final diagnosis was infective (n= 33), (tuberculoma n=17, pyogenic abscess n= 8, fungal abscess n= 3, sterile abscess n= 3, tubercular abscess n= 2), neoplastic (n= 21) (glial tumors n= 9, metastasis n= 8, lymphoma n= 4), and other (n= 15) abnormalities (subacute and chronic stroke n= 6, postictal edema n= 4, multiple sclerosis n= 2, Erdhiem Chester disease n= 2, Rosai Dorfmann disease n= 1). Succinate and acetate were detected only in pyogenic abscesses (2/4 cases), but amino acids were present in both pyogenic (4/8) and fungal (3/3) abscesses. Choline was seen not only in neoplasms (18) but also in tuberculomas (11/17), but was consistently absent in the abscesses. Lactate was present in glioblastoma (7/9), pyogenic (3/8) tubercular (2/2) and fungal (3/3) abscess. Isolated lipid resonance was found in Erdheim Chester disease (2/2) of the orbit, and lipid and choline was seen in Rosai Dorfmann's disease (1/1). Brain lesions containing lipid on (1)H-MRS could be differentiated by the presence of succinate and acetate in pyogenic abscess, and amino acids in pyogenic/fungal abscesses. Choline was seen in neoplasms and in tuberculomas, but not in the abscesses. Thus, the presence of a lipid peak, when combined with features on other MR pulse sequences and available clinical data can help arrive at a specific diagnosis. (1)H-MRS should not be interpreted in isolation: it should always be correlated with conventional imaging features, and performing (1)H-MRS in isolation remains an important pitfall.

10.
AJNR Am J Neuroradiol ; 29(6): 1147-52, 2008 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-18356472

RESUMO

BACKGROUND AND PURPOSE: Atypical and malignant meningiomas are uncommon tumors with aggressive behavior and higher mortality, morbidity, and recurrence compared with benign tumors. We investigated the utility of diffusion-weighted (DW) MR imaging to differentiate atypical/malignant from benign meningiomas and to detect histologic dedifferentiation to higher tumor grade. MATERIALS AND METHODS: We retrospectively compared conventional and DW MR images (b-value 1000 s/mm(2)) acquired on a 1.5T clinical scanner between 25 atypical/malignant and 23 benign meningiomas. The optimal cutoff for the absolute apparent diffusion coefficient (ADC) and normalized ADC (NADC) ratio to differentiate between the groups was determined by using receiver operating characteristic (ROC) analysis. RESULTS: Irregular tumor margins, peritumoral edema, and adjacent bone destruction occurred significantly more often in atypical/malignant than in benign meningiomas. The mean ADC of atypical/malignant meningiomas (0.66 +/- 0.13 x 10(-3) mm(2)/s) was significantly lower compared with benign meningiomas (0.88 +/- 0.08 x 10(-3) mm(2)/s; P < .0001). Mean NADC ratio in the atypical/malignant group (0.91 +/- 0.18) was also significantly lower than the benign group (1.28 +/- 0.11; P < .0001), without overlap between groups. ROC analysis showed that ADC and NADC thresholds of 0.80 x 10(-3) mm(2)/s and 0.99, respectively, had the best accuracy: at the NADC threshold of 0.99, the sensitivity and specificity were 96% and 100%, respectively. Two patients had isointense benign tumors on initial DW MR imaging, and these became hyperintense with the decrease in ADC and NADC below these thresholds when they progressed to atypical and malignant meningiomas on recurrence. CONCLUSIONS: ADC and NADC ratios in atypical/malignant meningiomas are significantly lower than in benign tumors. Decrease in ADC and NADC on follow-up imaging may suggest dedifferentiation to higher tumor grade.


Assuntos
Imagem de Difusão por Ressonância Magnética/métodos , Interpretação de Imagem Assistida por Computador/métodos , Neoplasias Meníngeas/diagnóstico , Meningioma/diagnóstico , Adulto , Desdiferenciação Celular , Feminino , Humanos , Masculino , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
11.
Singapore Med J ; 47(8): 719-23, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-16865216

RESUMO

Retropharyngeal haematoma is a rare cause of rapid neck swelling that may result in fatal upper respiratory airway obstruction. Reported causes include trauma, surgery, retropharyngeal inflammation, carotid aneurysm, aberrant artery at the thoracic inlet and bleeding diathesis. We report a 90-year-old man who developed rapid and progressive neck swelling following a minor traumatic episode. Computed tomography showed a large low-density retropharyngeal haematoma extending from the skull base to the mediastinum, with suspected extravasation. The right vertebral artery angiogram confirmed contrast agent extravasation arising from a small branch artery. This was treated with temporary distal flow arrest and particle embolisation.


Assuntos
Obstrução das Vias Respiratórias/terapia , Velocidade do Fluxo Sanguíneo , Embolização Terapêutica , Hematoma/terapia , Hemorragias Intracranianas/terapia , Lesões do Pescoço/complicações , Doenças Faríngeas/terapia , Artéria Vertebral/lesões , Idoso de 80 Anos ou mais , Obstrução das Vias Respiratórias/etiologia , Angiografia , Extravasamento de Materiais Terapêuticos e Diagnósticos , Hematoma/diagnóstico por imagem , Hematoma/etiologia , Humanos , Hemorragias Intracranianas/diagnóstico por imagem , Masculino , Lesões do Pescoço/diagnóstico por imagem , Doenças Faríngeas/diagnóstico por imagem , Doenças Faríngeas/etiologia , Tomografia Computadorizada por Raios X
12.
Singapore Med J ; 45(7): 330-3, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15221049

RESUMO

Enhancement of intracranial thrombosed aneurysms is an uncommon finding on magnetic resonance (MR) imaging, and can present diagnostic difficulties and complicate management decisions. We report a 46-year-old man who had an enhancing thrombosed intracranial aneurysm observed on 3T MR imaging. There was angiographical correlation, with follow-up serial MR imaging documenting regression and improvement. Findings are typical for benign intravascular papillary endothelial hyperplasia. Differential diagnoses of giant serpentine intracranial aneurysm and malignant angiosarcoma are discussed.


Assuntos
Angiografia Digital , Angiografia Cerebral , Endotélio Vascular/patologia , Imageamento Tridimensional , Aneurisma Intracraniano/diagnóstico , Trombose Intracraniana/diagnóstico , Imageamento por Ressonância Magnética , Seguimentos , Humanos , Hiperplasia , Aneurisma Intracraniano/patologia , Trombose Intracraniana/patologia , Masculino , Pessoa de Meia-Idade
13.
Singapore Med J ; 44(10): 526-30, 2003 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-15024457

RESUMO

OBJECTIVE: Dynamic perfusion magnetic resonance (MR) techniques may be used to track the susceptibility effects of gadolinium contrast material as it passes through the brain. We describe three intracranial tumours that showed progressively rising signal intensity above the baseline during first-pass contrast-enhanced echo-planar imaging (EPI) MR imaging. METHODS: Multiphase acquisition using single-shot EPI was performed during rapid bolus contrast injection. Ten studies, using either spin-echo or gradient-echo EPI sequences, were carried out in eight patients with intracranial tumours. Time-signal intensity graphs and regional cerebral blood volume (rCBV) were reviewed. RESULTS: In seven studies, the signal intensity within the tumour showed initial signal drop and quick recovery to baseline and increased rCBV. Three studies revealed progressively rising signal intensity. These patients were all imaged using a spin-echo EPI method and subsequent histology revealed meningioma, hemangiopericytoma and pinealblastoma. CONCLUSION: Dynamic perfusion MR methods may be used to study intracranial tumours. However, in short relaxation time spin-echo EPI, the T1- effect of gadolinium becomes noticeable during the first-pass acquisition in extra-axial tumours that lack a well-developed blood-brain barrier. Careful selection of patients and pulse sequence is essential to avoid this potential pitfall.


Assuntos
Neoplasias Encefálicas/patologia , Meios de Contraste , Imagem Ecoplanar , Gadolínio DTPA , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
14.
Antimicrob Agents Chemother ; 41(6): 1313-8, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9174190

RESUMO

2'-beta-Fluoro-2',3'-dideoxyadenosine (F-ddA) is an acid-stable purine dideoxynucleoside analog active against a wide spectrum of human immunodeficiency virus type 1 (HIV-1) and HIV-2 strains in vitro. F-ddA is presently undergoing a phase I clinical trial at the National Cancer Institute. We induced HIV-1 variants resistant to F-ddA by exposing wild-type HIV-1 (HIV-1LAI) to increasing concentrations of F-ddA in vitro. After 18 passages, the virus was fourfold less sensitive to F-ddA than HIV-1LAI. Sequence analyses of the passage 18 virus revealed changes in three amino acids in the reverse transcriptase (RT)-encoding region of the pol gene: P to S at codon 119 (P119S; present in 3 of 13 and 28 of 28 molecular clones before and after F-ddA exposure, respectively), V179D (0 of 13 and 9 of 28, respectively), and L214F (9 of 13 and 28 of 28, respectively). Drug sensitivity assays using recombinant infectious clones confirmed that P119S was directly responsible for the reduced sensitivity of HIV-1 to F-ddA. Various infectious clones with single or multiple amino acid substitutions conferring viral resistance against nucleoside RT inhibitors, including HIV-1 variants with multi-dideoxynucleoside resistance, were generally sensitive to F-ddA. The moderate level of resistance of HIV-1 to F-ddA, together with the lack of conferment of significant cross-resistance by the F-ddA-associated amino acid substitutions, warrants further investigation of F-ddA as a potential antiviral agent for use in treatment of HIV-1 infection.


Assuntos
Fármacos Anti-HIV/farmacologia , Didesoxiadenosina/análogos & derivados , HIV-1/efeitos dos fármacos , HIV-1/genética , Animais , Células COS , Nucleotídeos de Desoxiadenina/farmacologia , Didesoxiadenosina/farmacologia , Didesoxinucleotídeos , Resistência Microbiana a Medicamentos , Genes pol , Transcriptase Reversa do HIV/efeitos dos fármacos , Transcriptase Reversa do HIV/metabolismo , Humanos , Testes de Sensibilidade Microbiana , Mutação , Inibidores da Transcriptase Reversa/farmacologia , Nucleotídeos de Timina/farmacologia , Zidovudina/análogos & derivados , Zidovudina/farmacologia
15.
Biochem J ; 321 ( Pt 3): 751-7, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9032463

RESUMO

Fibronectin fragments have both catabolic and anabolic activities toward articular cartilage explants in vitro. Whereas a 1 nM concentration of an N-terminal 29 kDa fibronectin fragment (Fn-f) increases the proteoglycan (PG) content of cartilage without induction of matrix metalloproteinases (MMPs), 0.1-1 microM Fn-f temporarily suppresses PG synthesis and enhances MMP release. The higher concentrations cause an initially rapid PG depletion during the first week of culture, followed by much slower PG loss and gradually increasing rates of PG synthesis. To test for the involvement of mediators, human articular cartilage was cultured with Fn-f, and conditioned media were assayed for selected cytokines and factors. With 1 nM Fn-f, the release of the anabolic factors, insulin growth factor-I and transforming growth factor beta1, from cultured cartilage was enhanced by 50-100% during the entire 28-day culture period and this was associated with both supernormal rates of PG synthesis and PG content. However, the higher concentrations of Fn-f additionally enhanced release, by at least 10-fold, of the cytokines, tumour necrosis factor alpha, interleukin-1alpha, interleukin-1beta and interleukin-6 while causing depletion of cartilage PG. Release of tumour necrosis factor alpha, interleukin 1beta and interleukin 1alpha peaked at days 2, 3 and 9 during or slightly after the period of maximal PG depletion and decreased to control levels by days 7, 7 and 21 respectively, whereas release of interleukin 6 was enhanced throughout the culture period. Neutralizing antibodies to the catabolic cytokines reduced Fn-f-mediated MMP-3 release and suppression of PG synthesis. The temporal aspects of this interplay between catabolic and anabolic factors are consistent with the kinetics of Fn-f-mediated cartilage damage and attempted repair and may be relevant to cartilage damage and repair in vivo.


Assuntos
Cartilagem/metabolismo , Citocinas/metabolismo , Fibronectinas/metabolismo , Fatores Etários , Anticorpos/imunologia , Anticorpos/farmacologia , Células Cultivadas , Cicloeximida/farmacologia , Ensaio de Imunoadsorção Enzimática , Humanos , Hidrólise , Fator de Crescimento Insulin-Like I/metabolismo , Interleucina-1/metabolismo , Interleucina-1/farmacologia , Interleucina-6/metabolismo , Interleucina-6/farmacologia , Cinética , Metaloproteinase 3 da Matriz/análise , Metaloproteinase 3 da Matriz/metabolismo , Fragmentos de Peptídeos/metabolismo , Fragmentos de Peptídeos/farmacologia , Proteoglicanas/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Fator de Necrose Tumoral alfa/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Cicatrização/fisiologia
16.
Inflamm Res ; 46(11): 467-71, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9427068

RESUMO

OBJECTIVE AND DESIGN: The objective was to determine if agents that suppress catabolism might also enhance repair of irreversibly damaged cartilage. MATERIAL: Articular cartilage from bovine metacarpophalangeal joints was studied in explant culture. TREATMENT: Fibronectin fragments or IL-1 alpha, which potently cause proteoglycan (PG) loss from cartilage, were added to cultures also containing the catabolism-blocking agents: insulin-like growth factor-1, or N-acetylcysteine, or Arg-Gly-Asp-Ser peptide, and the effects of these agents on blocking PG loss determined. To test for repair or restoration of PG, cartilage was first damaged, damage agents removed and inhibitory agents added. METHODS: Each mean and SD value for cartilage PG content was determined by assays of papain digests of cartilage from three similar cultures. RESULTS: The agents either partially or fully blocked PG loss and promoted repair. CONCLUSIONS: Normally irreversible cartilage damage was reversed by slowing ongoing catabolic processes during attempted repair. Thus, catabolic inhibitors have reparative potential.


Assuntos
Cartilagem Articular/efeitos dos fármacos , Fibronectinas/toxicidade , Interleucina-1/toxicidade , Fragmentos de Peptídeos/toxicidade , Proteoglicanas/metabolismo , Acetilcisteína/farmacologia , Animais , Cartilagem Articular/patologia , Bovinos , Fibronectinas/antagonistas & inibidores , Fator de Crescimento Insulin-Like I/farmacologia , Interleucina-1/antagonistas & inibidores , Articulação Metacarpofalângica , Oligopeptídeos/farmacologia
17.
Biochim Biophys Acta ; 1317(2): 134-42, 1996 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8950199

RESUMO

Fibronectin fragments damage cartilage in vitro by greatly enhancing metalloproteinases and suppressing proteoglycan (PG) synthesis which results in severe cartilage PG depletion. Since reactive oxygen species (ROS) have been implicated in catabolic cytokine action and preliminary data suggested that catabolic cytokines such as TNF-alpha, IL-1 alpha, IL-1 beta and IL-6 are responsible for fibronectin fragment mediated damage, selected anti-oxidants (AOs) were tested as inhibitors of cytokine. ROS and fibronectin fragment activity. Damage was measured by depletion of cartilage PG during tissue culture. The AO, N-acetylcysteine (NAC), decreased the extent of cartilage PG depletion caused by TNF-alpha and IL-1 alpha and by the ROS, hydrogen peroxide and superoxide anion, confirming that the cytokines operate through ROS and that ROS can initiate cartilage PG depletion. NAC at 0.1 and 1 mM, totally suppressed PG depletion caused by a highly potent amino-terminal 29-kDa fibronectin fragment (Fn-f) for 14 days in culture. NAC at 10 mM totally blocked Fn-f mediated PG depletion for 21 days and increased the cartilage PG content by 30% above normal levels. Glutathione (10 microM) and DMSO (1%) were also totally effective while catalase and superoxide decreased Fn-f mediated damage only during the first week and superoxide dismutase alone caused damage after 1 wk. The AOs caused protection by reducing the major catabolic activities of the Fn-f: enhanced release of stromelysin-1 (MMP-3) and suppression of PG and protein synthesis. NAC also decreased normal rates of PG degradation and increased the half-lives of labeled PG in both control and Fn-f treated cartilage. We conclude that the Fn-f mediates cartilage chondrolysis through ROS, consistent with the involvement of catabolic cytokines in the Fn-f mechanism, and that AOs greatly reduce Fn-f mediated cartilage chondrolysis. In an accompanying manuscript we also report that AOs promote reparative responses in Fn-f and cytokine treated cartilage.


Assuntos
Antioxidantes/farmacologia , Cartilagem Articular/metabolismo , Colágeno/metabolismo , Fibronectinas/metabolismo , Proteoglicanas/metabolismo , Alopurinol/farmacologia , Animais , Catalase/metabolismo , Bovinos , Técnicas de Cultura , Inibidores Enzimáticos/farmacologia , Fibronectinas/química , Glutationa/metabolismo , Humanos , Interleucina-1/farmacologia , Metaloproteinase 3 da Matriz/metabolismo , Fragmentos de Peptídeos , Sulfatos/metabolismo , Superóxido Dismutase/metabolismo , Fator de Necrose Tumoral alfa/farmacologia , Xantina Oxidase/antagonistas & inibidores
18.
Biochim Biophys Acta ; 1317(2): 143-8, 1996 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8950200

RESUMO

In an accompanying manuscript, it was shown that the cartilage chondrolytic activities of fibronectin fragments (Fn-f), which are mediated through catabolic cytokines such as TNF-alpha, IL-1 and IL-6, could be suppressed by anti-oxidants (AOs). The AOs neutralized reactive oxygen species (ROS) which are known to mediate catabolic cytokine action. The objective in this work was to test whether AOs would promote restoration of proteoglycan (PG) in Fn-f treated cartilage, since under normal culturing conditions, PG is not restored after removal of the Fn-f. Cartilage was first cultured with an amino-terminal 29-kDa Fn-f to cause loss of about half of the total PG and then treated with NAC (1 and 10 mM) or glutathione (10 microM) or DMSO (0.1 or 1%). Treatment with NAC and glutathione maximally caused restoration of PG within 14 days to normal or supernormal levels, while DMSO was less effective. Catalase, but not superoxide dismutase, enhanced PG content to a small but significant extent. The restoration of PG in Fn-f treated cartilage occurred throughout the full depth of the cartilage slices as shown by histochemical analysis. However, removal of the AO allowed a subsequent decrease in PG content suggesting that the AOs had not blocked cytokine expression but had merely suppressed cytokine activities. Addition of NAC to IL-1 treated cartilage promoted a restoration of PG, while addition to chymopapain or trypsin treated cartilage was not very effective, suggesting that the effect of AOs requires a cytokine driven damage system. We conclude that the AOs promote a restoration of PG in the Fn-f treated cartilage by suppressing the effects of catabolic cytokines. The data suggest a potential for AOs in reversing tissue damage caused by cytokines.


Assuntos
Antioxidantes/farmacologia , Cartilagem Articular/metabolismo , Fibronectinas/fisiologia , Proteoglicanas/metabolismo , Acetilcisteína/farmacologia , Animais , Cartilagem Articular/citologia , Catalase/farmacologia , Bovinos , Quimopapaína/farmacologia , Técnicas de Cultura , Dimetil Sulfóxido/farmacologia , Fibronectinas/química , Glutationa/farmacologia , Interleucina-1/farmacologia , Fragmentos de Peptídeos , Superóxido Dismutase/farmacologia , Tripsina/farmacologia
19.
Arch Biochem Biophys ; 334(2): 325-31, 1996 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-8900407

RESUMO

Addition of fibronectin fragments to bovine articular cartilage explant cultures results in enhanced release of metalloproteinases and rapid cartilage proteoglycan (PG) degradation and loss. The chondrolysis begins with rapid PG degradation which markedly slows after 1 week. Preliminary observations suggest that catabolic cytokines mediate chondrolytic activities of the fibronectin fragments. The objectives of this work were to investigate the correlations between: (a) release of specific cytokines; (b) release of the metalloproteinase (MMP), stromelysin-1 (MMP-3); (c) release of the tissue inhibitor of MMPs, TIMP-1, and; (d) degradation and release of PG from cultured cartilage. We report that human articular cartilage cultured with an amino-terminal 29-kDa fragment (Fn-f) at 0.1 microM, released enhanced levels of TNF-alpha, IL-1beta, and IL-1alpha with peaks at Days 2, 3, and 9, respectively. MMP-3 release was elevated with a peak at Day 6 and a profile similar to that for the Fn-f-induced cartilage PG depletion. IL-6 release was enhanced within 2 days and continued at the same level throughout the culture period but this did not lead to enhanced release of TIMP-1, a known activity of IL-6. These data suggest that in the early chondrolytic events induced in cultured cartilage by Fn-f, enhanced MMP-3 release and maximal degradation and release of PG from cultured cartilage are kinetically associated with elevated release of the catabolic cytokines, TNF-alpha, IL-1beta, and IL-1alpha. Further, a later period of slowing PG loss and slowing MMP-3 release is associated with greatly slowed release of these cytokines, but prolonged release of IL-6. This model of cartilage damage may be useful for studies of the interplay between cytokines and the effects of combinations of cytokines on cartilage homeostasis.


Assuntos
Cartilagem Articular/metabolismo , Citocinas/biossíntese , Fibronectinas/farmacologia , Metaloproteinase 3 da Matriz/biossíntese , Fragmentos de Peptídeos/farmacologia , Proteoglicanas/metabolismo , Idoso , Animais , Cartilagem Articular/efeitos dos fármacos , Cartilagem Articular/imunologia , Bovinos , Feminino , Glicoproteínas/biossíntese , Homeostase , Humanos , Interleucina-1/biossíntese , Interleucina-6/biossíntese , Cinética , Masculino , Pessoa de Meia-Idade , Técnicas de Cultura de Órgãos , Inibidores Teciduais de Metaloproteinases , Fator de Necrose Tumoral alfa/biossíntese
20.
Singapore Med J ; 36(6): 621-7, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8781635

RESUMO

Mesial temporal lobe epilepsy due to mesial temporal sclerosis is a distinctive syndrome and a surgically remediable form of epilepsy. We present 26 Singaporean cases of mesial temporal lobe epilepsy defined by clinical, electroencephalographic and MR features and validated by good surgical outcome (12 seizure free, 5 with two or fewer seizures) in all 17 patients who have so far undergone surgery and who have been followed up for at least 6 months. Sixty-five percent of patients experienced their first seizure in the setting of a febrile illness. Seventy-three percent of patients had seizure onset before the age of 10 years and the median interval between seizure onset and intractability of seizures was 3.75 years. 80.7% of patients had an aura and an equal number had at least one lateralizing sign during their seizures. Sixty-four percent of patients had predominantly unilateral anterior temporal interictal spikes. Eighty-eight percent of patients had seizures which were lateralised on scalp ictal EEG. MRI abnormalities were most frequently seen in the head and body of the hippocampal formation. Asymmetric hippocampal atrophy was more common than hippocampal T2 or T2* signal changes. There is much similarity in characteristics of mesial temporal lobe epilepsy in our population compared to what has been published regarding Caucasian subjects.


Assuntos
Epilepsia do Lobo Temporal/diagnóstico , Lobo Temporal , Adolescente , Adulto , Atrofia , Dominância Cerebral/fisiologia , Eletroencefalografia , Epilepsia do Lobo Temporal/fisiopatologia , Epilepsia do Lobo Temporal/cirurgia , Feminino , Seguimentos , Hipocampo/patologia , Hipocampo/fisiopatologia , Hipocampo/cirurgia , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Esclerose , Lobo Temporal/patologia , Lobo Temporal/fisiopatologia , Lobo Temporal/cirurgia , Resultado do Tratamento
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