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1.
Curr Res Neurobiol ; 5: 100097, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37404949

RESUMO

Background: Somatosensory deficits are frequently seen in acute stroke patients and may recover over time and affect functional outcome. However, the underlying mechanism of function recovery remains poorly understood. In the present study, progressive function alteration of the secondary somatosensory cortex (S2) and its relationship with regional perfusion and neurological outcome were examined using a monkey model of stroke. Methods and materials: Rhesus monkeys (n = 4) were induced with permanent middle cerebral artery occlusion (pMCAo). Resting-state functional MRI, dynamic susceptibility contrast perfusion MRI, diffusion-weighted, T1 and T2 weighted images were collected before surgery and at 4-6, 48, and 96 h post stroke on a 3T scanner. Progressive changes of relative functional connectivity (FC), cerebral blood flow (CBF), and CBF/Tmax (Time to Maximum) of affected S2 regions were evaluated. Neurological deficits were assessed using the Spetzler approach. Results: Ischemic lesion was evidently seen in the MCA territory including S2 in each monkey. Relative FC of injured S2 regions decreased substantially following stroke. Spetzler scores dropped substantially at 24 h post stroke but slightly recovered from Day 2 to Day 4. Relative FC progressively increased from 6 to 48 and 96 h post stroke and correlated significantly with relative CBFand CBF/Tmax changes. Conclusion: The present study revealed the progressive alteration of function connectivity in S2 during acute stroke. The preliminary results suggested the function recovery might start couple days post occlusion and collateral circulation might play a key role in the recovery of somatosensory function after stroke insult. The relative function connectivity in S2 may provide additional information for prediction of functional outcome in stroke patients.

2.
Life (Basel) ; 13(4)2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37109537

RESUMO

BACKGROUND: The oxygen extraction fraction (OEF) indicates the brain's oxygen consumption and can be estimated by using the quantitative susceptibility mapping (QSM) MRI technique. Recent studies have suggested that OEF alteration following stroke is associated with the viability of at-risk tissue. In the present study, the temporal evolution of OEF in the monkey brain during acute stroke was investigated using QSM. METHODS: Ischemic stroke was induced in adult rhesus monkeys (n = 8) with permanent middle cerebral artery occlusion (pMCAO) by using an interventional approach. Diffusion-, T2-, and T2*-weighted images were conducted on day 0, day 2, and day 4 post-stroke using a clinical 3T scanner. Progressive changes in magnetic susceptibility and OEF, along with their correlations with the transverse relaxation rates and diffusion indices, were examined. RESULTS: The magnetic susceptibility and OEF in injured gray matter of the brain significantly increased during the hyperacute phase, and then decreased significantly on day 2 and day 4. Moreover, the temporal changes of OEF in gray matter were moderately correlated with mean diffusivity (MD) (r = 0.52; p = 0.046) from day 0 to day 4. Magnetic susceptibility in white matter progressively increased (from negative values to near zero) during acute stroke, and significant increases were seen on day 2 (p = 0.08) and day 4 (p = 0.003) when white matter was significantly degenerated. However, significant reduction of OEF in white matter was not seen until day 4 post-stroke. CONCLUSION: The preliminary results demonstrate that QSM-derived OEF is a robust approach to examine the progressive changes of gray matter in the ischemic brain from the hyperacute phase to the subacute phase of stroke. The changes of OEF in gray matter were more prominent than those in white matter following stroke insult. The findings suggest that QSM-derived OEF may provide complementary information for understanding the neuropathology of the brain tissue following stroke and predicting stroke outcomes.

3.
Int J Biol Macromol ; 241: 124638, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37119889

RESUMO

Propylene glycol alginate sodium sulfate (PSS) is a heparinoid polysaccharide drug used in clinic for >30 years in China. But its allergy events happened from time to time and should not be ignored. Here, ammonium salt in PSS (PSS-NH4+), PSS fractions with high Mw (PSS-H-Mw) and low mannuronic acid (M) to guluronic acid (G) ratio (PSS-L-M/G) were found to induce allergic response by the structure-activity and impurity-activity relationships in vitro. Furthermore, we confirmed the reason and elucidated the mechanism accounted for allergic side effect of PSS in vivo. It was found that high IgE levels in PSS-NH4+ and PSS-H-Mw groups upregulate the cascade expression of Lyn-Syk-Akt or Erk and second messenger Ca2+, which accelerated mast cells (MCs) degranulation to release histamine, LTB4, TPS, and finally induced lung tissue injury. PSS-L-M/G caused a mild allergic symptom because it only enhanced the expression of p-Lyn and histamine release. In brief, PSS-NH4+ and PSS-H-Mw were main reasons to result in allergic response. Our results suggested that it is very necessary to control the range of Mw and the content of impurities (< 1 % ammonium salt) of PSS to guarantee its safety and effectiveness in clinical treatment.


Assuntos
Compostos de Amônio , Hipersensibilidade , Humanos , Alginatos/farmacologia , Polissacarídeos/farmacologia , Hipersensibilidade/tratamento farmacológico , Mastócitos
4.
Surg Endosc ; 37(2): 1077-1085, 2023 02.
Artigo em Inglês | MEDLINE | ID: mdl-36109360

RESUMO

BACKGROUND: Gastroesophageal reflux disease (GERD) is often associated with esophageal stricture, particularly benign esophageal stricture. We aimed to evaluate the effects of balloon catheter dilation (BD) combined with laparoscopic fundoplication (LF) surgery and proton pump inhibitors (PPIs) in patients with reflux-induced esophageal strictures. METHODS: We retrospectively analyzed 116 patients with reflux-induced benign esophageal strictures who underwent balloon dilatation therapy combined with PPIs (BD-PPIs group, n = 58) and balloon dilatation combined with LF (BD-LF group, n = 58). Patients were followed up for 24 months. The outcomes of the patients were monitored, including clinical success, symptom improvement, adverse events, and the frequency of esophagitis. RESULTS: At the latest follow-up, the rate of clinical success was higher in BD-LF group than in BD-PPIs group (80.4% vs. 57.7%, P = 0.011). The patients in the BD-PPIs group required more dilation sessions to achieve successful dilation, as compared to those in the BD-LF group (2.1 ± 1.2 vs. 0.7 ± 0.8, P < 0.001). The DeMeester score, number of reflux episodes for which pH was < 4, and lower esophageal sphincter pressure were significantly better in the BD-LF group than in the BD-PPIs group (all P < 0.001). The incidence of reflux esophagitis was higher in the BD-PPIs group than in the BD-LF group, at 24 months (58.8% vs. 18.2%, P = 0.003). CONCLUSIONS: Balloon dilatation with concomitant LF is effective and safe for esophageal stricture secondary to GERD. Moreover, antireflux surgery techniques, such as Nissen or Toupet procedure, should be added for reflux-induced benign esophageal stricture.


Assuntos
Estenose Esofágica , Refluxo Gastroesofágico , Laparoscopia , Humanos , Inibidores da Bomba de Prótons/uso terapêutico , Estenose Esofágica/cirurgia , Estudos Retrospectivos , Constrição Patológica/cirurgia , Resultado do Tratamento , Refluxo Gastroesofágico/cirurgia , Fundoplicatura/métodos , Laparoscopia/métodos
5.
Int J Mol Sci ; 23(10)2022 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-35628577

RESUMO

A novel function of retinoid X receptor beta (RXRß) in endothelial cells has been reported by us during the formation of atherosclerosis. Here, we extended the study to explore the cellular mechanisms of RXRß protein stability regulation. In this study, we discovered that murine double minute-2 (MDM2) acts as an E3 ubiquitin ligase to target RXRß for degradation. The result showed that MDM2 directly interacted with and regulated RXRß protein stability. MDM2 promoted RXRß poly-ubiquitination and degradation by proteasomes. Moreover, mutated MDM2 RING domain (C464A) or treatment with an MDM2 inhibitor targeting the RING domain of MDM2 lost the ability of MDM2 to regulate RXRß protein expression and ubiquitination. Furthermore, treatment with MDM2 inhibitor alleviated oxidized low-density lipoprotein-induced mitochondrial damage, activation of TLR9/NF-κB and NLRP3/caspase-1 pathway and production of pro-inflammatory cytokines in endothelial cells. However, all these beneficial effects were reduced by the transfection of RXRß siRNA. Moreover, pharmacological inhibition of MDM2 attenuated the development of atherosclerosis and reversed mitochondrial damage and related inflammation in the atherosclerotic process in LDLr-/- mice, along with the increased RXRß protein expression in the aorta. Therefore, our study uncovers a previously unknown ubiquitination pathway and suggests MDM2-mediated RXRß ubiquitination as a new therapeutic target in atherosclerosis.


Assuntos
Aterosclerose , Proteínas Proto-Oncogênicas c-mdm2 , Animais , Aterosclerose/genética , Células Endoteliais/metabolismo , Inflamação/genética , Camundongos , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Ubiquitinação
6.
Aging Brain ; 22022.
Artigo em Inglês | MEDLINE | ID: mdl-36589695

RESUMO

With the ultimate goal of developing a more representative animal model of Alzheimer's disease (AD), two female amyloid-ß-(Aß) precursor protein-transgenic (APPtg) rhesus monkeys were generated by lentiviral transduction of the APP gene into rhesus oocytes, followed by in vitro fertilization and embryo transfer. The APP-transgene included the AD-associated Swedish K670N/M671L and Indiana V717F mutations (APPSWE/IND) regulated by the human polyubiquitin-C promoter. Overexpression of APP was confirmed in lymphocytes and brain tissue. Upon sacrifice at 10 years of age, one of the monkeys had developed Aß plaques and cerebral Aß-amyloid angiopathy in the occipital, parietal, and caudal temporal neocortices. The induction of Aß deposition more than a decade prior to its usual emergence in the rhesus monkey supports the feasibility of creating a transgenic nonhuman primate model for mechanistic analyses and preclinical testing of treatments for Alzheimer's disease and cerebrovascular amyloidosis.

7.
Hepatology ; 75(6): 1373-1385, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34919746

RESUMO

BACKGROUND AND AIMS: To clarify high-risk factors and develop a nomogram model to predict biochemical resolution or biochemical nonresolution (BNR) in patients with chronic DILI. APPROACH AND RESULTS: Retrospectively, 3655 of 5326 patients with chronic DILI were enrolled from nine participating hospitals, of whom 2866 underwent liver biopsy. All of these patients were followed up for over 1 year and their clinical characteristics were retrieved from electronic medical records. The endpoint was BNR, defined as alanine aminotransferase or aspartate aminotransferase >1.5× upper limit of normal or alkaline phosphatase >1.1× ULN, at 12 months from chronic DILI diagnosis. The noninvasive high-risk factors for BNR identified by multivariable logistic regression were used to establish a nomogram, which was validated in an independent external cohort. Finally, 19.3% (707 of 3655) patients presented with BNR. Histologically, with the increase in liver inflammation grades and fibrosis stages, the proportion of BNR significantly increased. The risk of BNR was increased by 21.3-fold in patients with significant inflammation compared to none or mild inflammation (p < 0.001). Biochemically, aspartate aminotransferase and total bilirubin, platelets, prothrombin time, sex, and age were associated with BNR and incorporated to construct a nomogram model (BNR-6) with a concordance index of 0.824 (95% CI, 0.798-0.849), which was highly consistent with liver histology. These results were successfully validated both in the internal cohort and external cohort. CONCLUSIONS: Significant liver inflammation is a robust predictor associated with biochemical nonresolution. The established BNR-6 model provides an easy-to-use approach to assess the outcome of chronic DILI.


Assuntos
Doença Hepática Crônica Induzida por Substâncias e Drogas , Hepatite , Aspartato Aminotransferases , Doença Hepática Crônica Induzida por Substâncias e Drogas/diagnóstico , Doença Hepática Crônica Induzida por Substâncias e Drogas/etiologia , Doença Hepática Crônica Induzida por Substâncias e Drogas/patologia , Hepatite/patologia , Humanos , Inflamação/patologia , Fígado/patologia , Estudos Retrospectivos
8.
Investig Magn Reson Imaging ; 26(4): 265-274, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36698482

RESUMO

Background: The corticospinal tract (CST) is a major tract for motor function. It can be impaired by stroke. Its degeneration is associated with stroke outcome. Diffusion tensor imaging (DTI) tractography plays an important role in assessing fiber bundle integrity. However, it is limited in detecting crossing fibers in the brain. The crossing fiber angular resolution of intra-voxel structure (CFARI) algorithm shows potential to resolve complex fibers in the brain. The objective of the present study was to improve delineation of CST pathways in monkey brains scanned by conventional DTI. Methods: Healthy rhesus monkeys were scanned by diffusion MRI with 128 diffusion encoding directions to evaluate the CFARI algorithm. Four monkeys with ischemic occlusion were also scanned with DTI (b = 1000 s/mm2, 30 diffusion directions) at 6, 48, and 96 hours post stroke. CST fibers were reconstructed with DTI and CFARI-based tractography and evaluated. A two-way repeated MANOVA was used to determine significances of changes in DTI indices, tract number, and volumes of the CST between hemispheres or post-stroke time points. Results: CFARI algorithm revealed substantially more fibers originated from the ventral premotor cortex in healthy and stroke monkey brains than DTI tractography. In addition, CFARI showed better sensitivity in detecting CST abnormality than DTI tractography following stroke. Conclusion: CFARI significantly improved delineation of the CST in the brain scanned by DTI with 30 gradient directions. It showed better sensitivity in detecting abnormity of the CST following stroke. Preliminary results suggest that CFARI could facilitate prediction of function outcomes after stroke.

9.
Investig Magn Reson Imaging ; 26(4): 275-283, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36698483

RESUMO

Background: Investigation of stroke lesion has mostly focused on grey matter (GM) in previous studies and white matter (WM) degeneration during acute stroke is understudied. In the present study, monkeys were utilized to investigate the alterations of GM and WM in the brain following ischemic occlusion using diffusion tensor imaging (DTI). Methods: Permanent middle cerebral artery occlusion (pMCAO) was induced in rhesus monkeys (n=6) with an interventional approach. Serial DTI was conducted on a clinical 3T in the hyperacute phase (2-6 hours), 48, and 96 hours post occlusion. Regions of interest in GM and WM of lesion areas were selected for data analysis. Results: Mean diffusivity (MD), radial diffusivity (RD), and axial Diffusivity (AD) in WM decreased substantially during hyperacute stroke, as similar as those seen in GM. No obvious fractional anasotropy (FA) changes were seen in GM and WM during hyper acute phase. until 48 hours post stroke when significant fiber losses were oberved also. Pseudo-normalization of MD, AD, and RD was seen at 96 hours. Pathological changes of WM and GM were observed in ischemic areas at 8, 48, and 96 hours post stroke. Relative changes of MD, AD and RD of WM were correlated negatively with infarction volumes at 6 hours post stroke. Conclusion: The present study revealed the microstructural changes in gray matter and white matter of monkey brains during acute stroke by using DTI. The preliminary results suggest axial and radial diffusivity (AD and RD) may be sensitive surrogate markers to assess specific microstructural changes in white matter during hyper-acute stroke.

11.
Zhongguo Zhong Yao Za Zhi ; 46(11): 2718-2727, 2021 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-34296568

RESUMO

Coptidis Rhizoma, as a bulk medicinal material, is in great demand in clinical practice. Its quality is uneven in the market due to the mixture of genuine, counterfeit and adulterants. Therefore, it is particularly important to establish a quality control system for Coptidis Rhizoma. Based on the concept of Chinese medicine quality marker(Q-marker), the potential quality markers of Coptidis Rhizoma were analyzed and predicted from the perspective of chemistry and pharmacology. The sources of the Q-markers of Coptidis Rhizoma were identified by literature retrieval. The potential Q-markers were then screened through the visualization of the "components-targets-pathways" network. High performance liquid chromatography(HPLC) was used to establish a multi-indicator qualitative and quantitative control method featuring fingerprints for 10 batches of Coptidis Rhizoma. A supervised mode of orthogonality partial least squares method-discriminant analysis(OPLS-DA) was used to screen the main marker components that caused differences between groups. The literature review results showed that the alkaloids were the main source of Coptidis Rhizoma Q-markers.The fingerprints of 13 common peaks were successfully established, and berberine, palmatine, berberine and epiberberine were selected as Q-markers of Coptidis Rhizoma, and their contents were determined.Based on the concept of the Q-marker of traditional Chinese medicine, the four components can be selected as the Q-marker of Coptidis Rhizoma after comprehensive consideration. The results of this study are not only conducive to the quality evaluation of Coptidis Rhizoma on the market, but also provide a reference for the overall quality control of Coptidis Rhizoma and lay foundation for the future exploration of the mechanism of Coptidis Rhizoma.


Assuntos
Alcaloides , Medicamentos de Ervas Chinesas , Cromatografia Líquida de Alta Pressão , Análise Multivariada , Rizoma
12.
Int J Mol Sci ; 22(8)2021 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33920853

RESUMO

A self-nanoemulsifying drug delivery system (SNEDDS) was developed to enhance the absorption of heparin after oral administration, in which heparin was compounded with phospholipids to achieve better fat solubility in the form of heparin-phospholipid (HEP-Pc) complex. HEP-Pc complex was prepared using the solvent evaporation method, which increased the solubility of heparin in n-octanol. The successful preparation of HEP-Pc complex was confirmed by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, NMR, and SEM. A heparin lipid microemulsion (HEP-LM) was prepared by high-pressure homogenization and characterized. HEP-LM can enhance the absorption of heparin after oral administration, significantly prolong activated partial thromboplastin time (APTT) and thrombin time (TT) in mice, and reduce fibrinogen (FIB) content. All these outcomes indicate that HEP-LM has great potential as an oral heparin formulation.


Assuntos
Sistemas de Liberação de Medicamentos , Emulsões/química , Heparina/farmacologia , Nanopartículas/química , Fosfolipídeos/química , Administração Oral , Animais , Anticoagulantes/farmacologia , Varredura Diferencial de Calorimetria , Heparina/administração & dosagem , Masculino , Camundongos , Nanopartículas/ultraestrutura , Tamanho da Partícula , Espectroscopia de Prótons por Ressonância Magnética , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier
13.
Surg Endosc ; 35(7): 4035-4041, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33881623

RESUMO

BACKGROUND: Gastroesophageal reflux disease (GERD) is a common digestive disease, could cause extra-esophageal symptoms. Peroral endoscopic cardial constriction with band ligation (PECC-b) is a minimally invasive method for the treatment of GERD in recent years. The goals of this study were to evaluate the clinical efficacy of PECC-b to treat gastroesophageal reflux-related symptoms. METHODS: A retrospective study of patients undergoing PECC-b between January 2017 and December 2018 at a single institution was conducted. All patients confirmed GERD by endoscopy, esophageal PH-impedance monitoring, esophageal manometry and symptom questionnaires. The outcome measures included reflux-related scores, patients' satisfaction and drug independence after 12 months following surgery. RESULTS: A total of 68 patients, with follow-up of 12 months post surgery, were included in the final analysis. The symptom scores were all significantly decreased as compared with preoperation (P < 0.05). The esophageal symptom scores showed a better improvement than extra-esophageal symptoms (P < 0.001). Fifty-three (77.9%) patients achieved complete drug therapy independence and 52 (76.5%) patients were completely or partially satisfied with the symptom relief following surgery. CONCLUSIONS: The PECC-b is a safe, effective and recommended approach for the control of GERD-related symptoms. Further multicenter prospective studies are required to confirm these outcomes.


Assuntos
Refluxo Gastroesofágico , Constrição , Endoscopia , Monitoramento do pH Esofágico , Estudos de Viabilidade , Seguimentos , Refluxo Gastroesofágico/cirurgia , Humanos , Manometria , Estudos Retrospectivos , Resultado do Tratamento
14.
J Cancer ; 12(5): 1493-1498, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33531994

RESUMO

Background: Most esophageal cancer patients are diagnosed at an advanced stage when there are few effective treatments. Transarterial infusion chemotherapy is a local chemotherapy method wherein chemotherapeutic drugs are directly injected into tumor vessels. Methods: Transarterial infusion chemotherapy was performed on advanced esophageal cancer patients once a month, and each patient underwent 1-3 treatments. The clinical results, complications, and effectiveness rates of each treatment episode were recorded and analyzed. Results: Transarterial infusion chemotherapy was successfully performed in all patients, and no severe complications such as paraplegia or death were noted. Complete response, partial response, and stable disease were noted in 17.3% (13/75), 77.3% (58/75), and 5.3% (4/75) of cases after transarterial infusion chemotherapy, respectively. The total treatment efficacy (complete response + partial response) was 94.7%. All cases exhibited improvement in clinical stage, with a marked decrease in dysphagia. Subsequent treatments were administered to 13 patients, including radical radiation in 7 and chemotherapy in 6. During follow-up, death was caused by progressive carcinoma in 20, tumor-related pneumatic infection and respiratory failure in 11, and gastrointestinal hemorrhage in 17. The median survival time was 15 months and the 1-year survival rate was 58.1%. Conclusions: Transarterial infusion chemotherapy may be safely and effectively used for treatment of advanced esophageal cancer.

15.
Magn Reson Imaging ; 75: 134-140, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33127411

RESUMO

OBJECTIVE: Alfaxalone has been used increasingly in biomedical research and veterinary medicine of large animals in recent years. However, its effects on the cerebral blood flow (CBF) physiology and intrinsic neuronal activity of anesthetized brains remain poorly understood. METHODS: Four healthy adult rhesus monkeys were anesthetized initially with alfaxalone (0.125 mg/kg/min) or ketamine (1.6 mg/kg/min) for 50 min, then administrated with 0.8% isoflurane for 60 min. Heart rates, breathing beats, and blood pressures were continuously monitored. CBF data were collected using pseudo-continuous arterial spin-labeling (pCASL) MRI technique and rsfMRI data were collected using single-shot EPI sequence for each anesthetic. RESULTS: Both the heart rates and mean arterial pressure (MAP) remained more stable during alfaxalone infusion than those during ketamine administration. Alfaxalone reduced CBF substantially compared to ketamine anesthesia (grey matter, 65 ± 22 vs. 179 ± 38 ml/100g/min, p<0.001; white matter, 14 ± 7 vs. 26 ± 6 ml/100g/min, p < 0.05); In addition, CBF increase was seen in all selected cortical and subcortical regions of alfaxalone-pretreated monkey brains during isoflurane exposure, very different from the findings in isoflurane-exposed monkeys pretreated with ketamine. Also, alfaxalone showed suppression effects on functional connectivity of the monkey brain similar to ketamine. CONCLUSION: Alfaxalone showed strong suppression effects on CBF of the monkey brain.The residual effect of alfaxalone on CBF of isoflurane-exposed brains was evident and monotonous in all the examined brain regions when used as induction agent for inhalational anesthesia. In particular, alfaxalone showed similar suppression effect on intrinsic neuronal activity of the brain in comparison with ketamine. These findings suggest alfaxalone can be a good alternative to veterinary anesthesia in neuroimaging examination of large animal models. However, its effects on CBF and functional connectivity should be considered.


Assuntos
Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Circulação Cerebrovascular/efeitos dos fármacos , Ketamina/farmacologia , Pregnanodionas/farmacologia , Anestésicos Inalatórios/administração & dosagem , Anestésicos Inalatórios/farmacologia , Animais , Encéfalo/irrigação sanguínea , Frequência Cardíaca/efeitos dos fármacos , Isoflurano/administração & dosagem , Isoflurano/farmacologia , Macaca mulatta , Masculino , Pregnanodionas/administração & dosagem
16.
Neuroimage ; 227: 117645, 2021 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-33338613

RESUMO

The dorsolateral prefrontal cortex (DLPFC) and ventral lateral prefrontal cortex (VLPFC) play critical but different roles in working memory (WM) processes. Resting-state functional MRI (rs-fMRI) was employed to investigate the effects of neonatal hippocampal lesions on the functional connectivity (FC) between the hippocampus (H) and the DLPFC and VLPFC and its relation to WM performance in adult monkeys. Adult rhesus monkeys with neonatal H lesions (Neo-H, n = 5) and age- and gender-matched sham-operated monkeys (Neo-C, n = 5) were scanned around 10 years of age. The FC of H-DLPFC and H-VLPFC in Neo-H monkeys was significantly altered as compared to controls, but also switched from being positive in the Neo-C to negative in the Neo-H. In addition, the altered magnitude of FC between right H and bilateral DLPFC was significantly associated with the extent of the hippocampal lesions. In particular, the effects of neonatal hippocampal lesion on FC appeared to be selective to the left hemisphere of the brain (i.e. asymmetric in the two hemispheres). Finally, FC between H and DLPFC correlated with WM task performance on the SU-DNMS and the Obj-SO tasks for the control animals, but only with the H-VLPFC and SU-DNMS task for the Neo-H animals. In conclusion, the present rsfMRI study revealed that the neonatal hippocampal lesions significantly but differently altered the integrity in the functional connectivity of H-DLPFC and H-VLPFC. The similarities between the behavioral, cognitive and neural alterations in Neo-H monkeys and Schizophrenia (SZ) patients provide a strong translational model to develop new therapeutic tools for SZ.


Assuntos
Lesões Encefálicas/fisiopatologia , Hipocampo/lesões , Hipocampo/fisiopatologia , Vias Neurais/fisiopatologia , Córtex Pré-Frontal/fisiopatologia , Animais , Animais Recém-Nascidos , Feminino , Macaca mulatta , Imageamento por Ressonância Magnética , Masculino , Memória de Curto Prazo/fisiologia , Esquizofrenia/fisiopatologia
17.
Magn Reson Imaging ; 77: 194-203, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33359631

RESUMO

BACKGROUND: Diffusion MRI (dMRI) data acquisition protocols are well-established on modern high-field clinical scanners for human studies. However, these protocols are not suitable for the chimpanzee (or other large-brained mammals) because of its substantial difference in head geometry and brain volume compared with humans. Therefore, an optimal dMRI data acquisition protocol dedicated to chimpanzee neuroimaging is needed. METHODS: A multi-shot (4 segments) double spin-echo echo-planar imaging (MS-EPI) sequence and a single-shot double spin-echo EPI (SS-EPI) sequence were optimized separately for in vivo dMRI data acquisition of chimpanzees using a clinical 3T scanner. Correction for severe susceptibility-induced image distortion and signal drop-off of the chimpanzee brain was performed and evaluated using FSL software. DTI indices in different brain regions and probabilistic tractography were compared. A separate DTI data set from n=34 chimpanzees (13 to 56 years old) was collected using the optimal protocol. Age-related changes in diffusivity indices of optic nerve fibers were evaluated. RESULTS: The SS-EPI sequence acquired dMRI data of the chimpanzee brain with approximately doubled the SNR as the MS-EPI sequence given the same scan time. The quality of white matter fiber tracking from the SS-EPI data was much higher than that from MS-EPI data. However, quantitative analysis of DTI indices showed no difference in most ROIs between the SS-EPI and MS-EPI sequences. The progressive evolution of diffusivity indices of optic nerves indicated mild changes in fiber bundles of chimpanzees aged 40 years and above. CONCLUSION: The single-shot EPI-based acquisition protocol provided better image quality of dMRI for chimpanzee brains and is recommended for in vivo dMRI study or clinical diagnosis of chimpanzees (or other large animals) using a clinical scanner. Also, the tendency of FA decrease or diffusivity increase in the optic nerve of aged chimpanzees was seen but did not show significant age-related changes, suggesting aging may have less impact on optic nerve fiber integrity of chimpanzees, in contrast to previous results for both macaque monkeys and humans.


Assuntos
Envelhecimento/fisiologia , Encéfalo/diagnóstico por imagem , Encéfalo/fisiologia , Imagem de Difusão por Ressonância Magnética/métodos , Nervo Óptico/diagnóstico por imagem , Animais , Imagem Ecoplanar/métodos , Feminino , Masculino , Neuroimagem , Pan troglodytes
18.
Open Forum Infect Dis ; 7(6): ofaa208, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32626791

RESUMO

BACKGROUND: None of the current guidelines recommend antiviral therapy for inactive hepatitis B virus (HBV) carriers (IHCs). METHODS: In this real-world, multicenter, nonrandomized study, 32 participants meeting the inclusion criteria were enrolled 1:1 for treatment with peginterferon α-2b or monitoring without treatment based on participant preference. The expected treatment duration was 48 weeks. The primary end point was hepatitis B surface antigen (HBsAg) loss. The HBV vaccine could be injected after HBsAg loss. RESULTS: All patients had HBsAg levels of <20 IU/mL. The mean baseline HBsAg levels were 6.6 IU/mL and 5.8 IU/mL in the treated and untreated groups, respectively. Fifteen (93.8%) participants achieved HBsAg loss, 5 obtained HBsAg seroconversion after undergoing a mean of 19.7 weeks of therapy in the treated group, and no one in the follow-up group achieved HBsAg loss during a mean follow-up time of 12.6 months (P < .0001). Generally, the therapy was well tolerated. Nine of 11 individuals who exhibited HBsAg loss benefited from receiving the HBV vaccine. CONCLUSIONS: This study provides justification for further studies of short-course peginterferon α-2b for the functional cure of IHCs with low HBsAg levels. Additionally, HBV vaccine injection is beneficial after interferon-induced HBsAg loss.

19.
J Vasc Surg Venous Lymphat Disord ; 8(6): 945-952, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32418826

RESUMO

OBJECTIVE: Our study aimed to evaluate the safety and efficacy of sequential interventional therapy for Budd-Chiari syndrome (BCS) caused by obstruction of the inferior vena cava (IVC) with fresh thrombus in the IVC. METHODS: Full medical records were obtained for 20 patients with BCS associated with fresh IVC thrombus who received sequential interventional therapy from 2014 to 2019 at our hospital. All patients underwent small-diameter percutaneous transluminal angioplasty (PTA) balloon catheter predilation combined with sequential catheter-directed thrombolysis and large-diameter PTA balloon dilation. Ultrasound examinations were performed at 1 week, 1 month, 3 months, and every 6 months thereafter. Therapeutic effects and perioperative and postoperative adverse effects were recorded to assess the safety of the treatment. RESULTS: All 20 patients were treated with small PTA balloon catheters (diameter, 10-14 mm) to predilate the occlusive segment of the IVC. Urokinase 400,000 to 600,000 (465,000 ± 93,000) units was administered to patients through the catheter for 6 to 20 (9.7 ± 4.2) consecutive days postoperatively. Ultrasound re-examination showed that the IVC thrombus disappeared completely in 14 patients (70.0%), and a small amount of the old thrombus remained in 6 patients (30.0%). After thrombolysis, all 20 patients received PTA balloon dilation (diameter, 26-30 mm) in the stenosed IVC segment, and blood flow recovered subsequently. No pulmonary embolism or death occurred in the perioperative course. The perioperative survival rate was 100.0%. CONCLUSIONS: Sequential interventional therapy for BCS associated with fresh IVC thrombus is safe and effective.


Assuntos
Angioplastia com Balão , Síndrome de Budd-Chiari/terapia , Fibrinolíticos/administração & dosagem , Terapia Trombolítica , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem , Veia Cava Inferior , Adulto , Idoso , Angioplastia com Balão/efeitos adversos , Síndrome de Budd-Chiari/diagnóstico por imagem , Síndrome de Budd-Chiari/fisiopatologia , Terapia Combinada , Feminino , Fibrinolíticos/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Terapia Trombolítica/efeitos adversos , Fatores de Tempo , Resultado do Tratamento , Ativador de Plasminogênio Tipo Uroquinase/efeitos adversos , Veia Cava Inferior/diagnóstico por imagem , Veia Cava Inferior/fisiopatologia , Adulto Jovem
20.
Quant Imaging Med Surg ; 10(4): 824-834, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32355646

RESUMO

BACKGROUND: Multi-compartment diffusion models such as Neurite Orientation Dispersion and Density Imaging (NODDI) have been increasingly used for diffusion MRI (dMRI) data processing in biomedical research. However, those models usually require multiple HARDI shells that may increase scanning duration substantially, and their application can be hindered in uncooperative patients (like infants) accordingly. Also, it is highly expected that the same dataset can be explored with multiple diffusion models for retrieving complementary information. METHODS: Multiple gradient-encoding schemes which consisted of 4-6 shells, moderate b-values (bmax =1,500 or 2,000 s/mm2), and 32-80 gradient directions were explored. The corresponding time of acquisition (TA) for a single scan ranged from 3 to 8 minutes respectively. The dMRI protocols were tested on macaque monkeys using a 3T clinical setting. The data were analysed using both NODDI and diffusion basic spectrum imaging (DBSI) models. RESULTS: The maps of orientation dispersion index (ODI) and CSF were consistent across the 4-6 shell sampling schemes. However, the corresponding intra-cellular volume fraction (ICVF) maps showed reduced pixel counts [1,100±98 (80 directions) vs. 806±70 (32 directions), one slice] in white matter when fewer gradient directions or lower b-value was applied. The hindered diffusion and CSF ratio maps were comparable across these sampling schemes. The maps of restricted diffusion ratio varied across the schemes. However, its mean ratios (0.23±0.02 vs. 0.22±0.01) and pixel counts (1,540±70 vs. 1,510±38, one slice) between the schemes of 80 and 32 directions with b=2,000 s/mm2 were comparable. CONCLUSIONS: The present study reports a fast multi-shell dMRI data acquisition and processing strategy which allows for obtaining complementary information about microstructural alteration and inflammation from a single dMRI data set with both NODDI and DBSI models. The proposed approach may be particularly useful for characterizing the neurodegenerative disorders in uncooperative patients like children or acute stroke patients in which brain injury is associated with inflammation.

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