AAV-SPL 2.0, a Modified Adeno-Associated Virus Gene Therapy Agent for the Treatment of Sphingosine Phosphate Lyase Insufficiency Syndrome.

Sphingosine-1-phosphate lyase insufficiency syndrome (SPLIS) is an inborn error of metabolism caused by inactivating mutations in SGPL1, the gene encoding sphingosine-1-phosphate lyase (SPL), an essential enzyme needed to degrade sphingolipids. SPLIS features include glomerulosclerosis, adrenal insufficiency, neurological defects, ichthyosis, and immune deficiency. Currently, there is no cure for SPLIS, and severely affected patients often die in the first years of life. We reported that adeno-associated virus (AAV) 9-mediated SGPL1 gene therapy (AAV-SPL) given to newborn Sgpl1 knockout mice that model SPLIS and die in the first few weeks of life prolonged their survival to 4.5 months and prevented or delayed the onset of SPLIS phenotypes. In this study, we tested the efficacy of a modified AAV-SPL, which we call AAV-SPL 2.0, in which the original cytomegalovirus (CMV) promoter driving the transgene is replaced with the synthetic "CAG" promoter used in several clinically approved gene therapy agents. AAV-SPL 2.0 infection of human embryonic kidney (HEK) cells led to 30% higher SPL expression and enzyme activity compared to AAV-SPL. Newborn Sgpl1 knockout mice receiving AAV-SPL 2.0 survived ≥ 5 months and showed normal neurodevelopment, 85% of normal weight gain over the first four months, and delayed onset of proteinuria. Over time, treated mice developed nephrosis and glomerulosclerosis, which likely resulted in their demise. Our overall findings show that AAV-SPL 2.0 performs equal to or better than AAV-SPL. However, improved kidney targeting may be necessary to achieve maximally optimized gene therapy as a potentially lifesaving SPLIS treatment.

miRNA and mRNA Signatures in Human Acute Kidney Injury Tissue.

Acute kidney injury (AKI) is an important contributor to the development of chronic kidney disease (CKD). There is a need to understand molecular mediators that drive either recovery or progression to CKD. In particular, the role of miRNA and its regulatory role in AKI is poorly understood. We performed miRNA and mRNA sequencing on biobanked human kidney tissues obtained in the routine clinical care of patients with the diagnoses of AKI and minimal change disease (MCD), in addition to nephrectomized (Ref) tissue from individuals without known kidney disease. Transcriptomic analysis of mRNA revealed that Ref tissues exhibited a similar injury signature to AKI, not identified in MCD samples. The transcriptomic signature of human AKI was enriched with genes in pathways involved in cell adhesion and epithelial-to-mesenchymal transition (e.g., CDH6, ITGB6, CDKN1A ). miRNA DE analysis revealed upregulation of miRNA associated with immune cell recruitment and inflammation (e.g., miR-146a, miR-155, miR-142, miR-122). These miRNA (i.e., miR-122, miR-146) are also associated with downregulation of mRNA such as DDR2 and IGFBP6 , respectively. These findings suggest integrated interactions between miRNAs and target mRNAs in AKI-related processes such as inflammation, immune cell activation and epithelial-to-mesenchymal transition. These data contribute several novel findings when describing the epigenetic regulation of AKI by miRNA, and also underscores the importance of utilizing an appropriate reference control tissue to understand canonical pathway alterations in AKI.

Clustering-based spatial analysis (CluSA) framework through graph neural network for chronic kidney disease prediction using histopathology images.

Machine learning applied to digital pathology has been increasingly used to assess kidney function and diagnose the underlying cause of chronic kidney disease (CKD). We developed a novel computational framework, clustering-based spatial analysis (CluSA), that leverages unsupervised learning to learn spatial relationships between local visual patterns in kidney tissue. This framework minimizes the need for time-consuming and impractical expert annotations. 107,471 histopathology images obtained from 172 biopsy cores were used in the clustering and in the deep learning model. To incorporate spatial information over the clustered image patterns on the biopsy sample, we spatially encoded clustered patterns with colors and performed spatial analysis through graph neural network. A random forest classifier with various groups of features were used to predict CKD. For predicting eGFR at the biopsy, we achieved a sensitivity of 0.97, specificity of 0.90, and accuracy of 0.95. AUC was 0.96. For predicting eGFR changes in one-year, we achieved a sensitivity of 0.83, specificity of 0.85, and accuracy of 0.84. AUC was 0.85. This study presents the first spatial analysis based on unsupervised machine learning algorithms. Without expert annotation, CluSA framework can not only accurately classify and predict the degree of kidney function at the biopsy and in one year, but also identify novel predictors of kidney function and renal prognosis.

A study on aviation supply chain network controllability and control effect based on the topological structure.

The present paper focuses on the controllability of the aviation supply chain network and establishes the judgment criterion for structural controllability of the aviation supply chain network. We determine the control effect by applying the control input to different nodes in the aviation supply chain network. These control nodes include the core enterprises of the aviation supply chain network, the upstream suppliers, and the downstream distributors. It is observed that the control effect is better when the control input is applied to the upstream suppliers of the aviation supply chain network than to the core enterprises of the aviation supply chain network. It is also more desirable to apply the control input to the core enterprises than to the distributors. That is, the control effect is the weakest when the control input is applied to the distributors, whereas the effect is best on application of the control to the upstream suppliers in the supply chain (that is, by choosing the upstream suppliers as the controlled nodes in the aviation supply chain network).

Unsupervised machine learning for identifying important visual features through bag-of-words using histopathology data from chronic kidney disease.

Pathologists use visual classification to assess patient kidney biopsy samples when diagnosing the underlying cause of kidney disease. However, the assessment is qualitative, or semi-quantitative at best, and reproducibility is challenging. To discover previously unknown features which predict patient outcomes and overcome substantial interobserver variability, we developed an unsupervised bag-of-words model. Our study applied to the C-PROBE cohort of patients with chronic kidney disease (CKD). 107,471 histopathology images were obtained from 161 biopsy cores and identified important morphological features in biopsy tissue that are highly predictive of the presence of CKD both at the time of biopsy and in one year. To evaluate the performance of our model, we estimated the AUC and its 95% confidence interval. We show that this method is reliable and reproducible and can achieve 0.93 AUC at predicting glomerular filtration rate at the time of biopsy as well as predicting a loss of function at one year. Additionally, with this method, we ranked the identified morphological features according to their importance as diagnostic markers for chronic kidney disease. In this study, we have demonstrated the feasibility of using an unsupervised machine learning method without human input in order to predict the level of kidney function in CKD. The results from our study indicate that the visual dictionary, or visual image pattern, obtained from unsupervised machine learning can predict outcomes using machine-derived values that correspond to both known and unknown clinically relevant features.

Diagnostic efficacy and influence factors of urinary protein/creatinine ratio replacing 24-h urine protein as an evaluator of proteinuria in children.

PURPOSE: The aim was to investigate the diagnostic efficacy of urinary protein/creatinine ratio (UPCR) and factors influencing its substitutability of 24-h urine protein (24hUP) in children with proteinuria. METHODS: A total of 356 children were recruited, including 149 with non-nephrotic-range proteinuria and 207 with nephrotic-range proteinuria which were further divided into Henoch-Schönlein purpura nephritis (HSPN), lupus nephritis (LN), and primary nephrotic syndrome (PNS). The urine protein and creatinine were measured by routine methods. Bland-Altman analysis was used to test the agreement. Spearman correlation was performed to evaluate the relevance. The receiver operating characteristic curve was used to analyze the diagnostic efficacy of UPCR. RESULTS: Bland-Altman analysis showed there was an excellent agreement between UPCR and 24hUP in each group. Correlations between UPCR and 24hUP were strong in 356 children (r = 0.869) and in the non-nephrotic-range proteinuria group (r = 0.806), but moderate in nephrotic-range proteinuria group (r = 0.586). With the increase of nephrotic-range proteinuria, the correlations between UPCR and 24hUP were decreased further, however, after UPCR was adjusted by 24-h urine creatinine (24hUCr), the correlation coefficient was improved (r = 0.682). In three subgroups with nephrotic-range proteinuria, high correlation coefficient (r = 0.731) was observed in HSPN, but not in LN (r = 0.552) and PNS (r = 0.563). The sensitivity and specificity of UPCR for diagnosing nephrotic-range proteinuria were 89.9 % and 92.2%. CONCLUSIONS: UPCR is competent in evaluating proteinuria. The degree of proteinuria, 24hUCr and the underlying pathological types of renal disease may be the important influencing factors in the correlation between UPCR and 24hUP in children with nephrotic-range proteinuria.

Glomerular endothelial cell-podocyte stresses and crosstalk in structurally normal kidney transplants.

Increased podocyte detachment begins immediately after kidney transplantation and is associated with long-term allograft failure. We hypothesized that cell-specific transcriptional changes in podocytes and glomerular endothelial cells after transplantation would offer mechanistic insights into the podocyte detachment process. To test this, we evaluated cell-specific transcriptional profiles of glomerular endothelial cells and podocytes from 14 patients of their first-year surveillance biopsies with normal histology from low immune risk recipients with no post-transplant complications and compared these to biopsies of 20 healthy living donor controls. Glomerular endothelial cells from these surveillance biopsies were enriched for genes related to fluid shear stress, angiogenesis, and interferon signaling. In podocytes, pathways were enriched for genes in response to growth factor signaling and actin cytoskeletal reorganization but also showed evidence of podocyte stress as indicated by reduced nephrin (adhesion protein) gene expression. In parallel, transcripts coding for proteins required to maintain podocyte adherence to the underlying glomerular basement membrane were downregulated, including the major glomerular podocyte integrin α3 and the actin cytoskeleton-related gene synaptopodin. The reduction in integrin α3 protein expression in surveillance biopsies was confirmed by immunoperoxidase staining. The combined growth and stress response of patient allografts post-transplantation paralleled similar changes in a rodent model of nephrectomy-induced glomerular hypertrophic stress that progress to develop proteinuria and glomerulosclerosis with shortened kidney life span. Thus, even among patients with apparently healthy allografts with no detectable histologic abnormality including alloimmune injury, transcriptomic changes reflecting cell stresses are already set in motion that could drive hypertrophy-associated glomerular disease progression.

Efficacy of AAV9-mediated SGPL1 gene transfer in a mouse model of S1P lyase insufficiency syndrome.

Sphingosine-1-phosphate lyase insufficiency syndrome (SPLIS) is a rare metabolic disorder caused by inactivating mutations in sphingosine-1-phosphate lyase 1 (SGPL1), which is required for the final step of sphingolipid metabolism. SPLIS features include steroid-resistant nephrotic syndrome and impairment of neurological, endocrine, and hematopoietic systems. Many affected individuals die within the first 2 years. No targeted therapy for SPLIS is available. We hypothesized that SGPL1 gene replacement would address the root cause of SPLIS, thereby serving as a universal treatment for the condition. As proof of concept, we evaluated the efficacy of adeno-associated virus 9-mediated transfer of human SGPL1 (AAV-SPL) given to newborn Sgpl1-KO mice that model SPLIS and die in the first weeks of life. Treatment dramatically prolonged survival and prevented nephrosis, neurodevelopmental delay, anemia, and hypercholesterolemia. STAT3 pathway activation and elevated proinflammatory and profibrogenic cytokines observed in KO kidneys were attenuated by treatment. Plasma and tissue sphingolipids were reduced in treated compared with untreated KO pups. SGPL1 expression and activity were measurable for at least 40 weeks. In summary, early AAV-SPL treatment prevents nephrosis, lipidosis, and neurological impairment in a mouse model of SPLIS. Our results suggest that SGPL1 gene replacement holds promise as a durable and universal targeted treatment for SPLIS.

Near-Single-Cell Proteomics Profiling of the Proximal Tubular and Glomerulus of the Normal Human Kidney.

Molecular assessments at the single cell level can accelerate biological research by providing detailed assessments of cellular organization and tissue heterogeneity in both disease and health. The human kidney has complex multi-cellular states with varying functionality, much of which can now be completely harnessed with recent technological advances in tissue proteomics at a near single-cell level. We discuss the foundational steps in the first application of this mass spectrometry (MS) based proteomics method for analysis of sub-sections of the normal human kidney, as part of the Kidney Precision Medicine Project (KPMP). Using ~30-40 laser captured micro-dissected kidney cells, we identified more than 2,500 human proteins, with specificity to the proximal tubular (PT; n = 25 proteins) and glomerular (Glom; n = 67 proteins) regions of the kidney and their unique metabolic functions. This pilot study provides the roadmap for application of our near-single-cell proteomics workflow for analysis of other renal micro-compartments, on a larger scale, to unravel perturbations of renal sub-cellular function in the normal kidney as well as different etiologies of acute and chronic kidney disease.

SARS-CoV-2 receptor networks in diabetic and COVID-19-associated kidney disease.

COVID-19 morbidity and mortality are increased via unknown mechanisms in patients with diabetes and kidney disease. SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) for entry into host cells. Because ACE2 is a susceptibility factor for infection, we investigated how diabetic kidney disease and medications alter ACE2 receptor expression in kidneys. Single cell RNA profiling of kidney biopsies from healthy living donors and patients with diabetic kidney disease revealed ACE2 expression primarily in proximal tubular epithelial cells. This cell-specific localization was confirmed by in situ hybridization. ACE2 expression levels were unaltered by exposures to renin-angiotensin-aldosterone system inhibitors in diabetic kidney disease. Bayesian integrative analysis of a large compendium of public -omics datasets identified molecular network modules induced in ACE2-expressing proximal tubular epithelial cells in diabetic kidney disease (searchable at hb.flatironinstitute.org/covid-kidney) that were linked to viral entry, immune activation, endomembrane reorganization, and RNA processing. The diabetic kidney disease ACE2-positive proximal tubular epithelial cell module overlapped with expression patterns seen in SARS-CoV-2-infected cells. Similar cellular programs were seen in ACE2-positive proximal tubular epithelial cells obtained from urine samples of 13 hospitalized patients with COVID-19, suggesting a consistent ACE2-coregulated proximal tubular epithelial cell expression program that may interact with the SARS-CoV-2 infection processes. Thus SARS-CoV-2 receptor networks can seed further research into risk stratification and therapeutic strategies for COVID-19-related kidney damage.

SARS-CoV-2 receptor networks in diabetic and COVID-19 associated kidney disease.

COVID-19 morbidity and mortality is increased in patients with diabetes and kidney disease via unknown mechanisms. SARS-CoV-2 uses angiotensin-converting enzyme 2 (ACE2) for entry into host cells. Since ACE2 is a susceptibility factor for infection, we investigated how diabetic kidney disease (DKD) and medications alter ACE2 receptor expression in kidneys. Single cell RNA profiling of healthy living donor (LD) and DKD kidney biopsies revealed ACE2 expression primarily in proximal tubular epithelial cells (PTEC). This cell specific localization was confirmed by in situ hybridization. ACE2 expression levels were unaltered by exposures to renin angiotensin aldosterone system inhibitors in DKD. Bayesian integrative analysis of a large compendium of public -omics datasets identified molecular network modules induced in ACE2-expressing PTEC in DKD (searchable at hb.flatironinstitute.org/covid-kidney) that were linked to viral entry, immune activation, endomembrane reorganization, and RNA processing. The DKD ACE2-positive PTEC module overlapped with expression patterns seen in SARS-CoV-2 infected cells. Similar cellular programs were seen in ACE2-positive PTEC obtained from urine samples of 13 COVID-19 patients who were hospitalized, suggesting a consistent ACE2-coregulated PTEC expression program that may interact with the SARS-CoV-2 infection processes. Thus SARS-CoV-2 receptor networks can seed further research into risk stratification and therapeutic strategies for COVID-19 related kidney damage.

Corrigendum: Near-Single-Cell Proteomics Profiling of the Proximal Tubular and Glomerulus of the Normal Human Kidney.

[This corrects the article DOI: 10.3389/fmed.2020.00499.].

Applicability of Downscaling Land Surface Temperature by Using Normalized Difference Sand Index.

Land surface temperature (LST) in coarse spatial resolution derived from thermal infrared satellite images has limited use in many remote sensing applications. In this study, we improve our previous approach (multiple remote-sensing index approach of random forest) to downscale LST derived from Landsat 8 and MODIS in an arid oasis - desert ecotone of Zhangye city by designing a normalized difference sand index (NDSI), by the removal of land cover datasets and by the input of SAVI, NDBI and NDWI to downscale LST. Our result demonstrates that NDSI can determine the characteristic of the desert region, and that the distribution of downscaled LST matches those of oasis-desert ecosystems. Relative to the ground observation of HiWATER, our approach also produces relatively satisfactory downscaling results at July 21 (2013), with R2 and root-mean-square error of 0.99 and 1.25 K, respectively. Compared with other methods, our approach demonstrates higher accuracy and minimization of the retrieved Landsat 8 LST in the desert region. Optimal availability occurs in the vegetation and desert region. Our approach is suitable to LST downscaling in all seasons, especially in spring and summer. The model can further be applied in middle-high and middle-low spatial resolutions. The usefulness of the model is relatively satisfactory in the humid region (Nanjing city) but less accurate in the arid region.

Downscaling Land Surface Temperature in Complex Regions by Using Multiple Scale Factors with Adaptive Thresholds.

Many downscaling algorithms have been proposed to address the issue of coarse-resolution land surface temperature (LST) derived from available satellite-borne sensors. However, few studies have focused on improving LST downscaling in urban areas with several mixed surface types. In this study, LST was downscaled by a multiple linear regression model between LST and multiple scale factors in mixed areas with three or four surface types. The correlation coefficients (CCs) between LST and the scale factors were used to assess the importance of the scale factors within a moving window. CC thresholds determined which factors participated in the fitting of the regression equation. The proposed downscaling approach, which involves an adaptive selection of the scale factors, was evaluated using the LST derived from four Landsat 8 thermal imageries of Nanjing City in different seasons. Results of the visual and quantitative analyses show that the proposed approach achieves relatively satisfactory downscaling results on 11 August, with coefficient of determination and root-mean-square error of 0.87 and 1.13 °C, respectively. Relative to other approaches, our approach shows the similar accuracy and the availability in all seasons. The best (worst) availability occurred in the region of vegetation (water). Thus, the approach is an efficient and reliable LST downscaling method. Future tasks include reliable LST downscaling in challenging regions and the application of our model in middle and low spatial resolutions.

Ameliorative effects of Xue-Fu-Zhu-Yu decoction, Tian-Ma-Gou-Teng-Yin and Wen-Dan decoction on myocardial fibrosis in a hypertensive rat mode.

BACKGROUND: Xue-Fu-Zhu-Yu decoction (XFZYD), Tian-Ma-Gou-Teng-Yin (TMGTY) and Wen-Dan decoction (WDD) are Chinese herbal formulas used to treat hypertension and cardiovascular diseases in traditional Chinese medicine (TCM). The goal of our study is to determine if XFZYD, TMGTY or WDD treatment ameliorated myocardial fibrosis in spontaneously hypertensive rats (SHRs) and to identify the mechanisms underlying any beneficial effects observed during the courses of the investigation. METHODS: Forty-five 12-week-old male spontaneously hypertensive rats and five age-matched male Wistar-Kyoto control rats were studied for 16 weeks. Each day 6 g∙kg(-1) or 12 g∙kg(-1) of XFZYD, TMGTY or WDD was orally administered at the indicated dose, and the systolic blood pressure (SBP) of all rats was measured using the tail-cuff method. Collagen levels were measured via hydroxyproline content assays and histological examination. Transforming growth factor beta-1 (TGF-ß1) protein levels were determined via immunhistochemical and Western blot analysis. TGF-ß1 mRNA levels were assessed using real-time reverse transcription polymerase chain reaction. RESULTS: Systolic blood pressure was unaffected, but collagen and TGF-ß1 levels in SHRs treated with captopril and XFZYD (12 g∙kg(-1)) were significantly reduced when compared with untreated control SHRs. Administration of 12 g∙kg(-1) XFZYD increased myocardial cell protection and decreased TGF-ß1 mRNA and protein expression when compared with the other SHR treatment groups. CONCLUSIONS: XFZYD treatment demonstrated a superior ability to reverse myocardial fibrosis when compared with WDD or TMGTY treatment in SHRs. XFZYD also decreased TGF-ß1 mRNA and protein expression, suggesting that the TGF-ß1 signaling pathway plays a role in the therapeutic effects of XFZYD treatment.

Effects of ursodeoxycholic acid on the pharmacokinetics and pharmacodynamics of intravenous and oral midazolam in healthy volunteers.

Animal and in vitro studies suggest that ursodeoxycholic acid (UDCA) can induce cytochrome P450 3A (CYP3A) expression and enhance its activities. On the other hand, Becquemont et al. demonstrated that UDCA had no influence on intestinal CYP3A activities. The aim of this study was to investigate the effects of UDCA on the intestinal and hepatic CYP3A activities by administration of midazolam (MDZ), as a specific probe for CYP3A activity, in humans. This was a randomized, open-label, crossover study with two phases in 14 healthy volunteers. The volunteers received UDCA (300 mg/day) or placebo orally for 9 days. The pharmacokinetics and pharmacodynamics of intravenous MDZ (5 microg/kg) and oral MDZ (15 microg/kg) were assessed on days 8 and 9, respectively. The pharmacodynamics of MDZ was estimated by measuring peak saccadic velocity, postural away length, critical fusion flicker frequency, and visual analogue scale. UDCA did not affect the pharmacokinetic and pharmacodynamic parameters of intravenous and oral MDZ administrations. Our study suggests that the clinical dosage of UDCA could not affect both hepatic and intestinal CYP3A activities and that the drug interaction between UDCA and substrates for CYP3A is unlikely in humans.

Cilostazol suppresses adhesion of human neutrophils to HUVECs stimulated by FMLP and its mechanisms.

The interaction between neutrophils and endothelial cells (ECs) is of great importance in many physiological and pathological progresses. Although cilostazol (CLZ), a novel selective phosphodiesterase (PDE) type 3 inhibitor, has been proved to be useful in vasodilatation and inhibition of platelet aggregation, its effect on adhesion is not clearly known. In this study, we examined the effects and investigated the mechanisms of cilostazol on neutrophil adhesion to human umbilical endothelial cells (HUVECs) triggered by N-formyl-methionyl-leucyl-phenylal-anine (FMLP), a chemotactic peptide. The soluble vascular cell adhesive molecule-1 (sVCAM-1) release from FMLP (10 microM)-stimulated HUVECs was determined by ELISA kits. Fluo-2, a fluorescent indicator, was used to investigate intracellular free calcium concentration ([Ca2+]i) in HUVECs. HL-60 cells were induced to be neutrophilic by DMSO and loaded with Fluo-3, another fluorescent indicator, to detect [Ca2+]i, and CLA was used as a chemiluminescent indicator to determine superoxide production in neutrophilic cells. The result showed that CLZ (1-100 microM) significantly inhibited neutrophil adhesion to FMLP-stimulated HUVECs. In HUVECs, CLZ obviously downregulated sVCAM-1 level, while it had no meaningful influence [Ca2)]i. But in neutrophils, FMLP-activated superoxide generation and [Ca2+]i increase were found being inhibited by exposure to CLZ . Furthermore, we also demonstrated that Ca2+ increase was preceded to the superoxide generation in neutrophils. The results suggest that CLZ involves in adhesion reactions between neutrophil and ECs, partly via VCAM-1 expression in ECs, and decreasing [Ca2+]i induced activation of neutrophils, which means a lot to prevent atherosclerosis and other cardiovascular diseases.

[Effects of two metabolites of cultured marine fungus, Halorosellinia oceanicum 323, on the contraction of isolated guinea-pig ileum].

AIM: To investigate the effects of 323-A and 323-B, two isomers extracted from the metabolites of cultured marine fungus, Halorosellinia oceanicum 323, on the contraction of isolated guinea pig ileum (GPI). METHODS: The GPI contractions were recorded with a two-channel-physiological recorder with tension transducers. Cumulative dose-response curves of contractions of isolated GPI induced by histamine (Hist), acetylcholine (ACh) and potassium chloride (KCl) were constructed, then the influences of 323-A and 323-B on each curve were observed. Furthermore, possible mechanisms underlying effects of the two compounds were explored by analyzing their influences on the biphasic contractile response to ACh, with comparison of a calcium antagonist, verapamil (Ver). RESULTS: The data indicated that both 323-A and 323-B inhibited the contractile actions of GPI triggered by Hist, ACh and KCl in a concentration-dependent manner, with pD2' values of 5.13, 4.97, 5.36 and 5.51, 5.56, 5.62, respectively. The initial phase component of the ACh-elicited contractions, in the absence of external Ca2+, was significantly reduced by 323-A, 323-B, as well as Ver, whereas the subsequent sustained tonic contractions induced by adding Ca2+ to the bath solution were almost unaffected. CONCLUSION: These results suggest that 323-A and 323-B have calcium antagonistic effects similar to that of Ver in mechanisms, and they might have potential to be developed as calcium antagonists.

[Antioxidative activities of two metabolites of cultured marine fungus, Halorosellinia oceanicum 323 in vitro].

OBJECTIVE: To investigate the antioxidative effects of 323-A and 323-B, two isomers extracted from the metabolites of cultured marine fungus, Halorosellinia oceanicum 323 in vitro. METHODS: NADH-PMS-NBT system was used to produce superoxide free radical (O2*-), EDTANa2-Fe(II)-H2O2 system to generate hydroxyl free radical (*OH), H2O2 to stimulate oxidative hemolysis of erythrocytes of rats, Cys-Fe2+ to induce malondialdehyde (MDA) production in homogenates, and ferrous-ascorbic acid system to increase the turbidity of mitochondria suspension in the liver of rats. And the antioxidative activities of 323-A and 323-B were studied. RESULTS: 323-A and 323-B not only scavenge O2*- and *OH produced by the experimental systems directly, but also inhibit H2O2 stimulated oxidative hemolysis of erythrocytes of rats, depress MDA production in homogenates induced by Cys-Fe2+ system, and reduce the turbidity of mitochondria suspension in the liver of rats increased by ferrous-ascorbic acid system in vitro. CONCLUSION: 323-A and 323-B showed comprehensive cleaning actions on free radicals and protective effects on the functions of tissues and cells against oxidative lesion. The results suggested that the marine microorganic metabolites might be a novel and profound source of antioxidative reagents.

Effects of resveratrol on secondary damages after acute spinal cord injury in rats.

AIM: To study the effects of resveratrol (Res) on secondary spinal cord edema, the activity of lactate dehydrogenase (LDH), Na+, K+-ATPase, and malondialdehyde (MDA) content in experimental spinal cord injured (SCI) rats. METHODS: The weight-dropping method was used to produce the experimental SCI in adult rats. Res ( 50, 100 mg/kg) and methylprednisolone (MPSS) 100 mg/kg were injected ip immediately after the induction of SCI. The effects of Res on edema, LDH, Na+, K+-ATPase, and MDA were determined at 1 h, 24 h, and 48 h after SCI compared with MPSS. The electron microscope was employed to investigate the ultrastructural effects of Res on axons, neurons, and subcellular organelles after SCI. RESULTS: Res obviously inhibited the secondary spinal cord edema with the most remarkable suppressing rate by 11.5 % at 48 h. Res significantly suppressed the activities of the lactate dehydrogenase with the highest suppressing rate > 40 % at 24 h. Res markedly improved the Na+, K+-ATPase activities that were promoted to the biggest extent of 60 % at 48 h. At the same time, Res (50 and 100 mg/kg) obviously reduced MDA production in the injured spinal cord tissue in comparison with the SCI model, the most remarkable effect of Res was detected at 48 h with the inhibitory rate >40 %. The ultrastructural findings suggested that SCI caused profound spinal cord damage, which could be protected or improved by injection of Res and MPSS. CONCLUSION: Both Res and MPSS effectively protected the spinal cord from secondary spinal cord injures. But the effects of Res 50 and 100 mg/kg were stronger in improving the energy metabolism system and inhibiting the lipid peroxidation in the local injured spinal cord after SCI than MPSS at the dose of 100 mg/kg. Res might have greatly potent therapeutic effects on SCI.