Biopsy-free AI-aided precision MRI assessment in prediction of prostate cancer biochemical recurrence.

BACKGROUND: To investigate the predictive ability of high-throughput MRI with deep survival networks for biochemical recurrence (BCR) of prostate cancer (PCa) after prostatectomy. METHODS: Clinical-MRI and histopathologic data of 579 (train/test, 463/116) PCa patients were retrospectively collected. The deep survival network (iBCR-Net) is based on stepwise processing operations, which first built an MRI radiomics signature (RadS) for BCR, and predicted the T3 stage and lymph node metastasis (LN+) of tumour using two predefined AI models. Subsequently, clinical, imaging and histopathological variables were integrated into iBCR-Net for BCR prediction. RESULTS: RadS, derived from 2554 MRI features, was identified as an independent predictor of BCR. Two predefined AI models achieved an accuracy of 82.6% and 78.4% in staging T3 and LN+. The iBCR-Net, when expressed as a presurgical model by integrating RadS, AI-diagnosed T3 stage and PSA, can match a state-of-the-art histopathological model (C-index, 0.81 to 0.83 vs 0.79 to 0.81, p > 0.05); and has maximally 5.16-fold, 12.8-fold, and 2.09-fold (p < 0.05) benefit to conventional D'Amico score, the Cancer of the Prostate Risk Assessment (CAPRA) score and the CAPRA Postsurgical score. CONCLUSIONS: AI-aided iBCR-Net using high-throughput MRI can predict PCa BCR accurately and thus may provide an alternative to the conventional method for PCa risk stratification.

PI-RADSAI: introducing a new human-in-the-loop AI model for prostate cancer diagnosis based on MRI.

BACKGROUND: This study aims to develop and validate an artificial intelligence (AI)-aided Prostate Imaging Reporting and Data System (PI-RADSAI) for prostate cancer (PCa) diagnosis based on MRI. METHODS: The deidentified MRI data of 1540 biopsy-naïve patients were collected from four centres. PI-RADSAI is a two-stage, human-in-the-loop AI capable of emulating the diagnostic acumen of subspecialists for PCa on MRI. The first stage uses a UNet-Seg model to detect and segment biopsy-candidate prostate lesions, whereas the second stage leverages UNet-Seg segmentation is trained specifically with subspecialist' knowledge-guided 3D-Resnet to achieve an automatic AI-aided diagnosis for PCa. RESULTS: In the independent test set, UNet-Seg identified 87.2% (628/720) of target lesions, with a Dice score of 44.9% (range, 22.8-60.2%) in segmenting lesion contours. In the ablation experiment, the model trained with the data from three centres was superior (kappa coefficient, 0.716 vs. 0.531) to that trained with single-centre data. In the internal and external tests, the triple-centre PI-RADSAI model achieved an overall agreement of 58.4% (188/322) and 60.1% (92/153) with a referential subspecialist in scoring target lesions; when one-point margin of error was permissible, the agreement rose to 91.3% (294/322) and 97.3% (149/153), respectively. In the paired test, PI-RADSAI outperformed 5/11 (45.5%) and matched the performance of 3/11 (27.3%) general radiologists in achieving a clinically significant PCa diagnosis (area under the curve, internal test, 0.801 vs. 0.770, p < 0.01; external test, 0.833 vs. 0.867, p = 0.309). CONCLUSIONS: Our closed-loop PI-RADSAI outperforms or matches the performance of more than 70% of general readers in the MRI assessment of PCa. This system might provide an alternative to radiologists and offer diagnostic benefits to clinical practice, especially where subspecialist expertise is unavailable.

Performance of Artificial Intelligence-Aided Diagnosis System for Clinically Significant Prostate Cancer with MRI: A Diagnostic Comparison Study.

BACKGROUND: The high level of expertise required for accurate interpretation of prostate MRI. PURPOSE: To develop and test an artificial intelligence (AI) system for diagnosis of clinically significant prostate cancer (CsPC) with MRI. STUDY TYPE: Retrospective. SUBJECTS: One thousand two hundred thirty patients from derivation cohort between Jan 2012 and Oct 2019, and 169 patients from a publicly available data (U-Net: 423 for training/validation and 49 for test and TrumpeNet: 820 for training/validation and 579 for test). FIELD STRENGTH/SEQUENCE: 3.0T/scanners, T2 -weighted imaging (T2 WI), diffusion-weighted imaging, and apparent diffusion coefficient map. ASSESSMENT: Close-loop AI system was trained with an Unet for prostate segmentation and a TrumpetNet for CsPC detection. Performance of AI was tested in 410 internal and 169 external sets against 24 radiologists categorizing into junior, general and subspecialist group. Gleason score >6 was identified as CsPC at pathology. STATISTICAL TESTS: Area under the receiver operating characteristic curve (AUC-ROC); Delong test; Meta-regression I2 analysis. RESULTS: In average, for internal test, AI had lower AUC-ROC than subspecialists (0.85 vs. 0.92, P < 0.05), and was comparable to junior (0.84, P = 0.76) and general group (0.86, P = 0.35). For external test, both AI (0.86) and subspecialist (0.86) had higher AUC than junior (0.80, P < 0.05) and general reader (0.83, P < 0.05). In individual, it revealed moderate diagnostic heterogeneity in 24 readers (Mantel-Haenszel I2  = 56.8%, P < 0.01), and AI outperformed 54.2% (13/24) of readers in summary ROC analysis. In multivariate test, Gleason score, zonal location, PI-RADS score and lesion size significantly impacted the accuracy of AI; while effect of data source, MR device and parameter settings on AI performance is insignificant (P > 0.05). DATA CONCLUSION: Our AI system can match and to some case exceed clinicians for the diagnosis of CsPC with prostate MRI. EVIDENCE LEVEL: 3 TECHNICAL EFFICACY: Stage 2.

Case Report: De novo variant in myelin regulatory factor in a Chinese child with 46,XY disorder/difference of sex development, cardiac and urogenital anomalies, and short stature.

The myelin regulatory factor (MYRF; MIM# 608329) gene was first identified as a critical transcription factor involved in oligodendrocyte differentiation and central nervous system myelination. With the recent development of exome sequencing, pathogenic variants of MYRF had been considered as the cause of cardiac-urogenital syndrome (CUGS), 46,XY and 46,XX disorders/differences of sex development (DSDs), and nanophthalmos. Herein, we described a 4-year-7-month-old "girl" with ventricular septal defect, atrial septal defect, patent ductus arteriosus, severe pulmonary hypertension, moderate-to-severe tricuspid regurgitation, enlarged coronary sinus, left superior vena cava, and right lung hypoplasia at birth. Later, the patient developed short stature and amblyopia. Further examination revealed a karyotype 46,XY and visible uterus, whereas the presence of gonads were not explored. Laparoscopy revealed dysplasia of testicular gonad. Whole-exome sequencing (WES) was performed and a de novo heterozygous mutation in MYRF was identified, known as c.2817G > A/p. W939* (NM_001127392.3). Therefore, this case report presented multiple clinical manifestations with syndromic symptoms of CUGS, 46,XY DSD, and ocular symptoms. These new data expanded the phenotype of the MYRF variant and may benefit to characterize the phenotypes caused by the variants of this gene.

A clinical available decision support scheme for optimizing prostate biopsy based on mpMRI.

BACKGROUND: Combined MRI/Ultrasound fusion targeted biopsy (TBx) and systematic biopsy (SBx) results in better prostate cancer (PCa) detection relative to either TBx or SBx alone, while at the cost of higher number of biopsy cores and greater detection of clinically insignificant PCa. We therefore developed and evaluated a simple decision support scheme for optimizing prostate biopsy based on multiparametric (mp) MRI assessment. METHODS: Total 229 patients with suspicion of PCa underwent mpMRI before combined TBx/SBx were retrospectively included. Impacts of MRI characteristics such as Prostate Imaging-Reporting and Data System (PI-RADS) score, lesion size, zonal origination, and location on biopsy performance were evaluated. A clinically available decision support scheme relying on mpMRI assessment was subsequently developed as a triage test to optimize prostate biopsy process. Cost (downgrade, upgrade, and biopsy core)-to-Effectiveness (detection rate) was systemically compared. RESULTS: TBx achieved comparable detection rate to combined TBx/SBx in diagnosis of PCa and clinically significant PCa (csPCa) (PCa, 59% [135/229] vs 60.7% [139/229]; csPCa, 45.9% [105/229] vs 47.2% [108/229]; p-values > 0.05) and outperformed SBx (PCa, 42.4% [97/229]; csPCa, 28.4% [65/229]; p-values < 0.001). Specially, in personalized decision support scheme, TBx accurately detected all PCa (72.5% [74/102]) in PI-RADS 5 and larger (≥1 cm) PI-RADS 3-4 observations, adding SBx to TBx only resulted in 1.4% (1/74) upgrading csPCa. For smaller (<1 cm) PI-RADS 3-4 lesions, combined TBx/SBx resulted in relatively higher detection rate (51.2% [65/127] vs 48.0% [61/127]) and lower upgrading rate (30.6% [15/49] vs 36.7% [18/49]) than TBx. CONCLUSIONS: The benefit of SBx added to TBx was largely restricted to smaller PI-RADS score 3-4 lesions. Using our personalized strategy of solo TBx for PI-RADS 5 and larger (≥1 cm) PI-RADS score 3-4 lesions would avoid excess SBx in 44.5% (102/229) of all biopsy-naïve patients without compromising detection rate.

RtNet: a deep hybrid neural network for the identification of acute rejection and chronic allograft nephropathy after renal transplantation using multiparametric MRI.

BACKGROUND: Reliable diagnosis of the cause of renal allograft dysfunction is of clinical importance. The aim of this study is to develop a hybrid deep-learning approach for determining acute rejection (AR), chronic allograft nephropathy (CAN) and renal function in kidney-allografted patients by multimodality integration. METHODS: Clinical and magnetic resonance imaging (MRI) data of 252 kidney-allografted patients who underwent post-transplantation MRI between December 2014 and November 2019 were retrospectively collected. An end-to-end convolutional neural network, namely RtNet, was designed to discriminate between AR, CAN and stable renal allograft recipient (SR), and secondarily, to predict the impaired renal graft function [estimated glomerular filtration rate (eGFR) ≤50 mL/min/1.73 m2]. Specially, clinical variables and MRI radiomics features were integrated into the RtNet, resulting in a hybrid network (RtNet+). The performance of the conventional radiomics model RtRad, RtNet and RtNet+ was compared to test the effect of multimodality interaction. RESULTS: Out of 252 patients, AR, CAN and SR was diagnosed in 20/252 (7.9%), 92/252 (36.5%) and 140/252 (55.6%) patients, respectively. Of all MRI sequences, T2-weighted imaging and diffusion-weighted imaging with stretched exponential analysis showed better performance than other sequences. On pairwise comparison of resulting prediction models, RtNet+ produced significantly higher macro-area-under-curve (macro-AUC) (0.733 versus 0.745; P = 0.047) than RtNet in discriminating between AR, CAN and SR. RtNet+ performed similarly to the RtNet (macro-AUC, 0.762 versus 0.756; P > 0.05) in discriminating between eGFR ≤50 mL/min/1.73 m2 and >50 mL/min/1.73 m2. With decision curve analysis, adding RtRad and RtNet to clinical variables resulted in more net benefits in diagnostic performance. CONCLUSIONS: Our study revealed that the proposed RtNet+ model owned a stable performance in revealing the cause of renal allograft dysfunction, and thus might offer important references for individualized diagnostics and treatment strategy.

Integration of clinicopathologic identification and deep transferrable image feature representation improves predictions of lymph node metastasis in prostate cancer.

BACKGROUND: Accurate identification of pelvic lymph node metastasis (PLNM) in patients with prostate cancer (PCa) is crucial for determining appropriate treatment options. Here, we built a PLNM-Risk calculator to obtain a precisely informed decision about whether to perform extended pelvic lymph node dissection (ePLND). METHODS: The PLNM-Risk calculator was developed in 280 patients and verified internally in 71 patients and externally in 50 patients by integrating a set of radiologists' interpretations, clinicopathological factors and newly refined imaging indicators from MR images with radiomics machine learning and deep transfer learning algorithms. Its clinical applicability was compared with Briganti and Memorial Sloan Kettering Cancer Center (MSKCC) nomograms. FINDINGS: The PLNM-Risk achieved good diagnostic discrimination with areas under the receiver operating characteristic curve (AUCs) of 0.93 (95% CI, 0.90-0.96), 0.92 (95% CI, 0.84-0.97) and 0.76 (95% CI, 0.62-0.87) in the training/validation, internal test and external test cohorts, respectively. If the number of ePLNDs missed was controlled at < 2%, PLNM-Risk provided both a higher number of ePLNDs spared (PLNM-Risk 59.6% vs MSKCC 44.9% vs Briganti 38.9%) and a lower number of false positives (PLNM-Risk 59.3% vs MSKCC 70.1% and Briganti 72.7%). In follow-up, patients stratified by the PLNM-Risk calculator showed significantly different biochemical recurrence rates after surgery. INTERPRETATION: The PLNM-Risk calculator offers a noninvasive clinical biomarker to predict PLNM for patients with PCa. It shows improved accuracy of diagnosis support and reduced overtreatment burdens for patients with findings suggestive of PCa. FUNDING: This work was supported by the Key Research and Development Program of Jiangsu Province (BE2017756) and the Suzhou Science and Technology Bureau-Science and Technology Demonstration Project (SS201808).

[Research advances in the role of mTOR signaling pathway in autism spectrum disorder].

Mammalian target of rapamycin (mTOR) is an intracellular signaling pathway molecule which regulates various fundamental physiological processes. The mTOR signaling pathway plays an important role in synaptic plasticity, information transmission and processing, and neuroregulation. Dysregulation of the mTOR signaling pathway is generally considered to be related to the pathogenesis of autism spectrum disorder (ASD); meanwhile, the mTOR inhibitor can ameliorate the symptoms of ASD. The role of mTOR in the pathogenesis of ASD is summarized in this article to provide a theoretical basis for targeted therapy of ASD.

Childhood pentastomiasis: a report of three cases with the following-up data.

Pentastomiasis, a zoonotic parasitic disease, has been reported commonly in Africa and Asia. It is caused by pentastomes, which are annulated but unsegmented blood-sucking endoparasites. Fewer than 20 cases have been reported during the past two decades in China, and cases in children have been especially rare. Herein, we report three cases of pediatric patients with severe systemic symptoms, focusing on the clinical features, diagnosis, and therapy of this disease. The patients were two boys and one girl aged 3 to 13years. They all had a history of snake or worm ingested from snake and initial symptoms of fever, abdominal pain, diarrhea, and weight loss. Eosinophilia, anemia and elevated serum IgE levels were noted. Moreover, the large numbers of nodules, or even calcification, in the liver and/or lungs were noted by ultrasound, CT or MRI scans. These pentastomes were identified as Armillifer moniliformis, Porocephalus taiwana and Armillifer agkistrodontis. Praziquantel and mebendazole deworming treatments were adopted for the patients. Hence, pentastomiasis should be considered in the differential diagnosis for patients with multiple organ or system lesions, especially abdominal signs, that develop after the ingestion of snakes. Ultrasound, CT and MRI scans and laparoscopic approaches might be helpful for the diagnosis.

[Quantitative assessment of intrahepatic fat content in children and adolescents with non-alcoholic fatty liver disease].

OBJECTIVE: To quantitatively evaluate clinical significance of intrahepatic fat (IHF) content in children and adolescents with non-alcoholic fatty liver disease (NAFLD). METHODS: Ninety-three obese children were enrolled in this study. Physical parameters, liver function, serum lipids, glycemic and insulin related parameters were measured. Liver B-mode ultrasound (US) examination was performed. IHF content was quantified by 1H magnetic resonance spectroscopy (1H MRS). Three subgroups were classified according to the conditional diagnostic criteria for obese children: simple obesity (n=31), NAFLD-1 (US fatty liver and normal alanine aminotransterase, n=33) and NAFLD-2 (US fatty liver and elevated alanine aminotransterase, n=29). Twenty healthy age- and sex-matched children served as a control group. IHF content among the four groups was compared. The relationship of IHF content with other common clinical laboratory parameters and independent factors influencing increased IHF content were investigated. RESULTS: IHF content measured by 1H MRS was 0.80% (0.4%-1.0%), 2.9% (1.7%-4.30%), 14.0% (7.2%-17.5%) and 18.8% (14.0%-29.1%) respectively in the control, simple obese, NAFLD-1 and NAFLD-2 groups. There were significant differences in IHF content between the groups. Univariate correlation analysis demonstrated that IHF content was positively correlated with waist circumference, hip circumference, waisttohip ratio, body mass index, systolic blood pressure, diastolic blood pressure, alanine aminotransferase, aspartate aminoreansferase, γ-glutamic acid transtetase, triglyceride, low-density lipoprotein, OGTT 2-hour plasma glucose, fasting insulin, 2-hour insulin and insulin resisfence, and negatively correlated with high-density lipoprotein. Multivariate linear regression analysis demonstrated three independent risk factors for increased IHF content: increased waist circumference, increased 2-hour plasma glucose and decreased high-density lipoprotein levels. CONCLUSIONS: IHF content determined by 1H MRS can reflect early hepatic fatty infiltration and is closely related to the occurrence and progress of NAFLD in obese children and adolescents. There is a significant correlation between most of common clinical laboratory parameters and IHF content, and waist circumference, high-density lipoprotein and OGTT 2-hour plasma glucose are independent factors impacting IHF content.

Down-Klinefelter syndrome (48,XXY,+21) in a child with congenital heart disease: case report and literature review.

Congenital heart disease (CHD) is extremely rarely reported in 48, XYY, +21 karyotype. Herein, we reported one case of 48,XYY,+21 karyotype with CHD and reviewed the available literature. The phenotypic characteristics of the 4-month-old child showed the presence of features typical of mongoloid slant. X-ray detection showed the form of heart was corpulent and the bilateral mediastinum was broad. Doppler echocardiogram detection showed atrial septal and ventricular septal defects with patent ductus arteriosus, pulmonary hypertension and mild tricuspid regurgitation. Including this case, 63 cases of 48, XYY, +21 chromosome pattern have been reported. However, only 9 cases have CHD.

Follicular bronchiolitis in a child.

BACKGROUND: Follicular bronchiolitis (FB) is an uncommon but important pulmonary manifestation in children. METHODS: In this report, we present the clinical presentations and histopathological data of an 8-year-old boy with FB. RESULTS: The patient had a history of recurrent cough and dyspnea for 5 years with progressive worsening of symptoms. An initial pulmonary function test showed an obstructive ventilatory defect. Chest X-ray demonstrated miliary nodules. High-resolution computed tomography showed reticulonodular opacification and central consolidation. Histopathological examination revealed that lymphoid follicles with reactive germinal centers distributed along the bronchioles. The boy responded favorably to corticosteroid therapy and recovered well. CONCLUSIONS: Diagnosis of FB should be considered when a child presents with chronic bronchial obstruction. Open lung biopsy is necessary for confirmation of the diagnosis.

Ghrelin ameliorates hypoxia-induced pulmonary hypertension via phospho-GSK3 ß/ß-catenin signaling in neonatal rats.

Effective treatment and/or prevention strategies for neonatal persistent pulmonary hypertension of the newborn (PPHN) have been an important topic in neonatal medicine. However, mechanisms of impaired pulmonary vascular structure in hypoxia-induced PPHN are poorly understood and consequently limit the development of effective treatment. In this study, we aimed to explore the molecular signaling cascades in the lungs of a PPHN animal model and used primary cultured rat pulmonary microvascular endothelial cells to analyze the physiological benefits of ghrelin during the pathogenesis of PPHN. Randomly selected newborn rats were exposed to hypoxia (10-12%) or room air and received daily s.c. injections of ghrelin (150 µg/kg) or saline. After 2 weeks, pulmonary hemodynamics and morphometry were assessed in the rats. Compared with the control, hypoxia increased pulmonary arterial pressure, right ventricle (RV) hypertrophy, and arteriolar wall thickness. Ghrelin treatment reduced both the magnitude of PH and the RV/(left ventricle+septum (Sep)) weight ratio. Ghrelin protected neonatal rats from hypoxia-induced PH via the upregulation of phosphorylation of glycogen synthase kinase 3ß (p-GSK3ß)/ß-catenin signaling and associated with ß-catenin translocation to the nucleus in the presence of growth hormone secretagogue receptor-1a. Our findings suggest that s.c. administration of ghrelin improved PH and attenuated pulmonary vascular remodeling after PPHN. These beneficial effects may be mediated by the regulation of p-GSK3ß/ß-catenin expression. We propose ghrelin as a novel potential therapeutic agent for PPHN.

Novel chloride channel gene mutations in two unrelated Chinese families with myotonia congenita.

Myotonia congenita (MC) is a genetic disease characterized by mutations in the muscle chloride channel gene (CLCN1). To date, approximately 130 different mutations on the CLCN1 gene have been identified. However, most of the studies have focused on Caucasians, and reports on CLCN1 mutations in Chinese population are rare. This study investigated the mutation of CLCN1 in two Chinese families with MC. Direct sequencing of the CLCN1 gene revealed a heterozygous mutation (892G>A, resulting in A298T) in one family and a compound heterozygous mutations (782A>G, resulting in Y261C; 1679T>C, resulting in M560T) in the other family, None of the 100 normal controls had these mutations. Our findings add more to the available information on the CLCN1 mutation spectrum, and provide a valuable reference for studying the mutation types and inheritance pattern of CLCN1 in the Chinese population.

[Analysis of lung function in children with respiratory diseases and its clinical application].

OBJECTIVE: To evaluate the clinical application of lung function analysis in diagnosis of children respiratory diseases. METHODS: Respiratory function was evaluated with portable lung function detector in 6 261 children with respiratory diseases. FEV1, FVC and PEFR were measured in 268 children with cough variant asthma (CVA) and 147 children with asthma (AS), and the results were self-compared during follow-up. RESULT: There were no significant differences in above parameters between children with cough variant asthma and those with asthma (P>0.05). Lung functions of asthma children were improved evidently by administration of glycocorticoid inhalator (P<0.001). CONCLUSION: Lung function detection is essential for diagnosis of asthma and it can be used as a reliable index for therapeutic effect of asthma children.

Activation of ATP-sensitive potassium channels prevents the cleavage of cytosolic mu-calpain and abrogates the elevation of nuclear c-Fos and c-Jun expressions after hypoxic-ischemia in neonatal rat brain.

The purpose of this study was to determine whether activation of ATP-sensitive K+ (KATP) channels with diazoxide (DIZ) is able to prevent the cleavage of cytosolic mu-calpain and abrogate the elevation of nuclear c-Fos and c-Jun protein (c-Fos, c-Jun) expressions after hypoxic-ischemia (HI) in brain. The model of hypoxic-ischemic brain injury (HIBI) was made in the 7-day-old Sprague-Dawley (SD) rats by left carotid arterial ligation and hypoxia (8% oxygen). DIZ was injected into the left lateral ventricle (5 microl, 1 mg/ml) before or post-hypoxic-ischemia (HI) insults. Western blot and computer image processing were used to detect the integrated density of nuclear c-Fos and c-Jun at 4 h and cleavage of cytosolic mu-calpain at 24 h after HI insults from cerebral cortical and hippocampal samples. Compared with HI controls (c-Fos=30.37+/-7.39 from cortical samples, 58.61+/-3.64 from hippocampal samples; c-Jun=52.48+/-14.23 from cortical samples, 35.55+/-4.73 from hippocampal samples), there was a significant down-regulation of c-Fos and c-Jun expressions from cortical and hippocampal samples in rats treated with DIZ before (c-Fos=11.10+/-4.64 from cortical samples, 4.82+/-3.38 from hippocampal samples; c-Jun=19.01+/-5.29 from cortical samples, 35.55+/-4.73 from hippocampal samples) or post- (c-Fos=18.81+/-7.93 from cortical samples, 11.33+/-7.05 from hippocampal samples; c-Jun=24.64+/-10.01 from cortical samples, 19.75+/-3.47 from hippocampal samples) HI insults. Furthermore, the ratio of 76 kD/80 kD of mu-calpain was down-regulated from cortical and hippocampal samples in rats treated with DIZ before or post-HI insults, demonstrating a significant difference compared with that observed in HI controls. Finally, the increase in DNA fragments caused by the HI injury was decreased or eliminated by the treatment with DIZ. These data suggests that activation of KATP channels by DIZ reduces the degree of mu-calpain proteolysis, and c-Fos and c-Jun expressions in immature brain may contribute to the neuroprotection of K(ATP) channel openers against HIBI.

Effect of diazoxide on regulation of vesicular and plasma membrane GABA transporter genes and proteins in hippocampus of rats subjected to picrotoxin-induced kindling.

Epileptiform discharges and behavioral seizures may be the consequences of excess excitation from inadequate inhibitory effects associated with gamma-aminobutyric acid (GABA). GABA is taken up and accumulated in synaptic vesicles by the action of vesicular GABA transporter (VGAT) before its release into the synaptic cleft, and removed from synaptic regions by the action of transporter proteins GABA transporter-1 (GAT-1) and GABA transporter-3 (GAT-3). In this experiment, the effects of diazoxide (DIZ) on the VGAT, GAT-1 and GAT-3 mRNA and protein levels in hippocampus, and on the seizure activities of picrotoxin (PTX)-induced kindling rats were observed. DIZ caused increase in the quantity of VGAT mRNAs and proteins, and down regulation of GABA transporters GAT-1 and GAT-3 mRNAs and proteins after the PTX re-kindling. Furthermore, DIZ produced not only a prompt but also a later suppression of PTX-induced seizures. Although DIZ has effects on ATP-sensitive potassium (K(ATP)) channels when measured in vitro, our study suggests that additional mechanisms of action may involve the regulation of GABA transporters, which may aid in understanding epileptogenesis and inform investigators about future design and development of K(ATP) channel openers to treat epilepsy.

[Time-course of mu-calpain activation, c-Fos, c-Jun, HSP70 and HSP27 expression in hypoxic-ischemic neonatal rat brain].

OBJECTIVE: The cascade of physiological events underlying hypoxic-ischemic brain damage (HIBD) remains to be fully established. The perinatal brain shows both an increased tolerance to hypoxic-ischemic (HI) injury and a faster and more complete recovery than the adult. It is, therefore, important to understand the sequence of events following hypoxia and ischemia in young animals. The present study aimed to clarify the time-course of the activation of the mu-calpain, and the expression of c-Fos, c-Jun, HSP70 and HSP27 proteins following severe HI (2 h hypoxia) and their relationship with each other. METHODS: A modified newborn rat model of HIBD that included a combination of hypoxia and ischemia as described by Rice was used. Forty-two postnatal 7-day-old Sprague-Dawley rats were randomly divided into seven groups (6 rats in each): 6 time-window groups and a normal control group. Samples were collected at 0, 1, 2, 4, 12 and 24 h after HI insults. The protein concentration was determined using a modified Bradford assay. mu-calpain activation, c-Fos, c-Jun, HSP70 and HSP27 expressions were observed respectively by Western blot from cortical and hippocampal samples. RESULTS: The cleavage of cytosolic mu-calpain was observed from both cortical and hippocampal samples in neonatal rats after HI. The ratio 76:80 of mu-calpain was increased significantly post-HI and reached a maximum at 24 h in cortex and at 12 h in hippocampus after HI. The expressions of c-Fos and c-Jun from both cortical and hippocampal samples in neonatal rats were up-regulated and peaked at 2 or 4 h after HI, demonstrating significant differences at 1, 2, 4, and 12 h compared with that observed in the control (P < 0.05). When compared with that observed in cortex, the nuclear c-Fos expression from hippocampal samples was highly elevated at 2, 4 and 12 h but significantly decreased at 24 h after HI (P < 0.05), while the nuclear c-Jun expression from hippocampal samples was highly elevated at 0 and 1 h but significantly decreased at 4 and 24 h after HI (P < 0.05). Similarly, the expressions of HSP70 and HSP27 from both cortical and hippocampal samples were up-regulated and reached a maximum at 12 or 24 h after HI, demonstrating significant differences at 12 or 24 h both in cortex and hippocampus for HSP70, and at 24 h in cerebral cortex as well as at 12 and 24 h in hippocampus for HSP27 compared with the control (P < 0.05). Furthermore, in comparison with that observed in cortex, the HSP70 expression from hippocampal samples was highly elevated at 1 h, but significantly decreased at 4, 12 and 24 h after HI (P < 0.05), while the HSP27 expression was permanently elevated in hippocampus after HI. CONCLUSION: The neuronal injury induced by HI insults appears to involve many ongoing and simultaneous mechanisms. HI activates the calpains immediately, which may contribute to neuron apoptosis, and induces a significant brain neuroprotection, since there is an increased HSP70 expression and a relatively late remarkable HSP27 expression in hypoxic-ischemic neonatal rat brain. Nuclear c-Fos and c-Jun may participate in the pathogenesis of HIBD.

Electro-acupuncture preconditioning abrogates the elevation of c-Fos and c-Jun expression in neonatal hypoxic-ischemic rat brains induced by glibenclamide, an ATP-sensitive potassium channel blocker.

This study aimed to clarify the neuroprotective mechanism of electro-acupuncture (EA) preconditioning on hypoxic-ischemic brain injury (HIBI). Using Western blot, the expression of c-fos protein (c-Fos) and c-jun protein (c-Jun) induced by glibenclamide, an ATP-sensitive potassium (K(ATP)) channel blocker was examined from cerebral cortical and hippocampal samples in neonatal hypoxic-ischemic rats, with or without EA preconditioning. EA was performed on Hegu (LI4), a well-known acupoint commonly used in Oriental medicine for the treatment of neuronal injury resulting from hypoxia-ischemia (HI). Preconditioned rats were treated with either diazoxide, a K(ATP) channel opener, glibenclamide, or sterile saline injected into the left lateral ventricle (i.c.v.), with or without EA administration before HI insult. Interestingly, low c-Fos and c-Jun expressions were found both in diazoxide and EA groups, 24 h after HI. Furthermore, significant differences in relative optical density (ROD) were found between glibenclamide and HI control groups (P< or =0.05), as well as between the group administered glibenclamide after EA and the HI control group (P< or =0.05). However, the level of c-Fos and c-Jun expression in the group administered glibenclamide after EA was significantly lower than in the glibenclamide group (P< or =0.05). The present findings indicate that the effectiveness of EA preconditioning against HIBI may be mediated via the opening of K(ATP) channels.