Association between lactate dehydrogenase and the risk of diabetic kidney disease in patients with type 2 diabetes

Objective

This study aims to investigate the association between lactate dehydrogenase (LDH) and the risk of diabetic kidney disease (DKD) in patients with type 2 diabetes (T2D).

Methods

The study enrolled patients with diagnosis of T2D between 2009 and 2018 from the National Nutrition and Health Examination Survey (NHANES) database. Demographic information, laboratory test, and diagnostic data were collected. Restricted cubic spline (RCS) plots were used to assess the dose-effect relationship between LDH levels and the risk of DKD in patients with T2D. Based on LDH levels, individuals were divided into higher and lower groups using dichotomy, and multivariate logistic regression analysis was conducted to explore the relationship between different LDH levels and the risk of DKD in T2D patients. Stratified analysis was performed to assess the consistency of the result.

Results

A total of 4888 patients were included in the study, with 2976 (60.9%) patients without DKD and 1912 (39.1%) patients with DKD. RCS plots showed that the risk of DKD increased with increasing LDH levels. Multifactorial logistic regression analysis revealed that T2D patients with higher LDH levels had a 45% increased risk of DKD compared to those with lower LDH levels (OR=1.45; 95% CI: 1.11-1.89). Furthermore, each standard deviation increase in LDH level was associated with a 24% increase in DKD incidence among T2D patients (OR=1.24; 95% CI: 1.07-1.44). Stratified analysis consistently supported these findings.

Conclusions

LDH can serve as a valuable biomarker for screening DKD in patients with T2D.

Randomized controlled trial of nalfurafine for refractory pruritus in hemodialysis patients

Background: Chronic kidney disease-associated pruritus (CKD-aP) is very common and sometimes refractory to treatment in hemodialysis patients. In a trial conducted in Japan, nalfurafine, effectively reduced itching of treatment-resistant CKD-aP. Our present bridging study aimed to evaluate the efficacy and safety of nalfurafine in Chinese cohort with refractory CKD-aP.Methods: In this phase III, multicenter bridging study conducted at 22 sites in China, 141 Chinese cases with refractory CKD-aP were randomly (2:2:1) assigned to receive 5 μg, 2.5 μg of nalfurafine or a placebo orally for 14 days in a double-blind manner. The primary end point was the mean decrease in the mean visual analogue scale (VAS) from baseline.Results: A total of 141 patients were included. The primary endpoint analysis based on full analysis set (FAS), the difference of mean VAS decrease between 5 μg nalfurafine and placebo group was 11.37 mm (p = .041); the difference of mean VAS decrease between 2.5 μg and placebo group was 8.81 mm, but not statistically significantly different. Both differences were greater than 4.13 mm, which met its predefined success criterion of at least 50% efficacy of the key Japanese clinical trial. The per protocol set (PPS) analysis got similar results. The incidence of adverse drug reactions (ADRs) was 49.1% in 5μg, 38.6% in 2.5 μg and 33.3% in placebo group. The most common ADR was insomnia, seen in 21 of the 114 nalfurafine patients.Conclusions: Oral nalfurafine effectively reduced itching with few significant ADRs in Chinese hemodialysis patients with refractory pruritus.

Recent advances in pyroptosis, liver disease, and traditional Chinese medicine: A review

In recent years, the incidence of liver disease has increased, becoming a major cause of death. Various liver diseases are intricately linked to pyroptosis, which is one of the most common forms of programmed cell death. As a powerful weapon in the fight against liver diseases, traditional Chinese medicine (TCM) can affect pyroptosis via a number of routes, including the classical, nucleotide oligomerization domain-like receptors protein 3/caspase-1/gasdermin D (GSDMD) pathway, the nonclassical lipopolysaccharide/caspase-11/GSDMD pathway, the ROS/caspase-3/gasdermin E pathway, the caspase-9/caspase-3/GSDMD pathway, and the Apaf-1/caspase-11/caspase-3 pathway. In this review, we provide an overview of pyroptosis, the interplay between pyroptosis and liver diseases, and the mechanisms through which TCM regulates pyroptosis in liver diseases. The information used in the text was collected and compiled from the databases of PubMed, Web of Science, Scopus, CNKI, and Wanfang Data up to June 2023. The search was not limited with regard to the language and country of the articles. Research and review articles were included, and papers with duplicate results or unrelated content were excluded. We examined the current understanding of the relationship between pyroptosis and liver diseases as well as the advances in TCM interventions to provide a resource for the identification of potential targets for TCM in the treatment of liver diseases.

Phylogeny and species diversity of the genus Helvella with emphasis on eighteen new species from China

Helvella is a widespread, frequently encountered fungal group appearing in forests, but the species diversity and molecular phylogeny of Helvella in China remains incompletely understood. In this work, we performed comprehensive phylogenetic analyses using multilocus sequence data. Six datasets were employed, including a five-locus concatenated dataset (ITS, nrLSU, tef1-α, rpb2, hsp), a two-locus concatenated dataset (ITS, nrLSU), and four single-locus datasets (ITS) that were divided based on the four different phylogenetic clades of Helvella recognized in this study. A total of I 946 sequences were used, of which 713 were newly generated, including 170 sequences of ITS, 174 sequences of nrLSU, 131 sequences of tef1-α, 107 sequences of rpb2 and 131 sequences of hsp. The phylogeny based on the five-locus concatenated dataset revealed that Helvellas. str. is monophyletic and four phylogenetic clades are clearly recognized, i.e., Acetabulum clade, Crispa clade, Elastica clade, and Lacunosa clade. A total of 24 lineages or subclades were recognized, II of which were new, the remaining 13 corresponding with previous studies. Chinese Helvella species are distributed in 22 lineages across four clades. Phylogenetic analyses based on the two-locus concatenated dataset and four single-locus datasets confirmed the presence of at least 93 phylogenetic species in China. Among them, 58 are identified as known species, including a species with a newly designated lectotype and epitype, 18 are newly described in this paper, and the remaining 17 taxa are putatively new to science but remain unnamed due to the paucity or absence of ascomatal materials. In addition, the Helvella species previously recorded in China are discussed. A list of 76 confirmed species, including newly proposed species, is provided. The occurrence of H. crispa and H. elastica are not confirmed although both are commonly recorded in China. Citation: Mao N, Xu YY, Zhang YX, Zhou H, Huang XB, Hou CL, Fan L (2023). Phylogeny and species diversity of the genus Helvella with emphasis on eighteen new species from China. Fungal Systematics and Evolution 12: 111-152. doi: 10.3114/fuse.2023.12.08.

Dietary fiber intake and cognitive impairment in older patients with chronic kidney disease in the United States: A cross-sectional study

BACKGROUND

High-fiber diet has been associated with better cognitive performance. However, the association between dietary fiber intake and cognition in older patients with chronic kidney disease (CKD) remains unknown. Hence, this study aimed to investigate the effect of dietary fiber intake on cognition in older patients with CKD.

METHODS

This study included participants aged ≥60 years who provided data on social demography, cognitive tests (Consortium to Establish a Registry for Alzheimer's disease Word Learning [CERAD-WL], CERAD Delayed Recall [CERAD-DR], Animal Fluency Test [AFT], and Digit Symbol Substitution Test [DSST]), diet, and other potential cognition-related variables from the National Health and Nutrition Examination Survey 2011-2014. Fully-adjusted multivariate logistic regression subgroup models were performed, and multiple linear regression analyses were employed to examine the association between dietary fiber intake and cognition in patients with CKD.

RESULTS

A total of 2461 older adults were included, with 32% who suffered from CKD. Participants with CKD scored lower in CERAD-WL, CERAD-DR, AFT, and DSST. Patients with CKD consuming low dietary fiber (≤25 g/day) had a higher risk of CERAD-WL and DSST impairments. High dietary fiber intake eliminated the differences in CERAD-WL and DSST impairments between the CKD and non-CKD participants. However, no associations were observed between CKD and CERAD-DR and AFT impairments regardless of dietary fiber intake. A positive linear relationship between dietary fiber intake and AFT score was observed in older patients with CKD.

CONCLUSION

High dietary fiber intake may benefit cognitive function in older patients with CKD. High-fiber diet management strategies could potentially mitigate cognitive impairment in this group of patients.

CCL5 might be a prognostic biomarker and associated with immuno-therapeutic efficacy in cancers: A pan-cancer analysis

Purpose

Chemokine ligand 5 (CCL5), a vital member of the CC chemokine family, plays diverse roles in tumorigenesis, metastasis, and prognosis in various human tumors. However, no pan-cancer analysis has been conducted to illustrate its distinctive effects on clinical prognosis via underlying mechanisms and biological characteristics.

Methods

Herein, we exploited the existed public bioinformatics database, primarily TCGA database and GTEx data, to comprehensively analyze the value of CCL5 involved in patient prognosis.

Results

This study found that CCL5 was excessively expressed in most tumors and significantly associated with clinical prognosis in 10 out of 33 types of tumors. Notably, CCL5 might be an independent predictive biomarker of clinical outcome in SKCM patients, confirmed by univariate and multivariate Cox regression analysis. Furthermore, we acquired the genetic alteration status of CCL5 in multiple types of tumor tissues from TCGA cohorts. We revealed a potential correlation between the expression level of CCL5 and tumor mutational burden in 33 types of tumors. In addition, data showed that DNA methylation was associated with CCL5 gene expression in THCA, PRAD, LUSC, and BRCA cancers. Immune infiltration and immune checkpoints are fine indexes for evaluating immunotherapy. We uncovered that CCL5 was negatively correlated with the immune infiltration of CD8+ T cell, CD4+ T cell, macrophages, and gamma delta T cells in BRCA-basal and CESC tumors, while a significant positive correlation was observed in BLCA, COAD and other 7 types of tumors. Besides, CCL5 was closely associated with the immune checkpoint molecules in 8 types of tumors. The TIDE score was less in the CCL5 high-expressed group than in the CCL5 low-expressed group in SKCM patients, which indicated that CCL5 might be a fine monitor of immune response for immunotherapy. GO enrichment analysis data uncovered that cytokine-cytokine receptor interaction and chemokine signaling might be involved in the role of CCL5 in regulating tumor pathogenesis and prognosis.

Conclusion

In conclusion, CCL5 was preliminarly identified as a biomarker of immune response and prognosis for tumors patients via our first comprehensive pan-cancer analysis.

Panax Notoginseng Saponins Alleviate LPS-induced Fibrosis of HK-2 Cells by Inhibiting the Activation of NLRP3 Inflammasome and Pyroptosis

BACKGROUND

Renal fibrosis is related to impaired kidney function and can eventually lead to end-stage renal disease, for which no effective treatment is available. Panax notoginseng saponins (PNS), as a commonly used traditional Chinese medicine, is considered a possible alternative for the treatment of fibrosis.

OBJECTIVE

The purpose of the present study was to investigate the effects and possible mechanisms of PNS on renal fibrosis.

METHODS

HK-2 cells were used to induce renal fibrosis cell model by lipopolysaccharide (LPS), and the cytotoxicity of PNS on HK-2 cells was investigated. Cell damage, pyroptosis, and fibrosis were analyzed to investigate the effects of PNS on LPS-induced HK-2 cells. NLRP3 agonist Nigericin was used further to explore the inhibitory effect of PNS on LPS-induced pyroptosis so as to clarify the possible mechanism of PNS on renal fibrosis.

RESULTS

PNS had no cytotoxicity on HK-2 cells, and could reduce the apoptosis and the release of lactate dehydrogenase (LDH) and inflammatory cytokines of LPS-induced HK-2 cells, showing an alleviating effect on cell damage. PNS also reduced the expression of pyroptosis proteins NLRP3, IL-1β, IL-18, and Caspase-1, as well as fibrosis proteins α-SMA, collagen Ⅰ and p-Smad3/Smad3, which showed an inhibitory effect on LPS-induced pyroptosis and fibrosis. In addition, LPS-induced cell damage, pyroptosis, and fibrosis were aggravated after Nigericin treatment, while PNS alleviated the aggravation caused by Nigericin.

CONCLUSION

PNS inhibits pyroptosis by inhibiting the activation of NLRP3 inflammasome in LPS-induced HK-2 cells, which ultimately alleviates renal fibrosis and plays a good role in the treatment of kidney diseases.

Differentiation between atypical sinonasal non-Hodgkin's lymphoma and inverted papilloma

AIM

To seek additional magnetic resonance imaging (MRI) features to improve the accuracy of differentiation between atypical sinonasal non-Hodgkin's lymphoma (NHL) and inverted papilloma (IP) using conventional MRI and apparent diffusion coefficient (ADC) maps.

MATERIALS AND METHODS

MRI examinations from 44 atypical cases (21 NHLs and 23 IPs) in sinonasal regions were reviewed retrospectively. Imaging features included tumour laterality, extension, T1-weighted imaging (WI)/T2WI signal intensity homogeneity and ratios, enhancement homogeneity and ratios, and ADC_mean.

RESULTS

In cases of NHL, homogeneous signal intensity was often observed on T2WI, which was homogeneous and significantly less enhanced than the turbinate, with lower ADC_mean. Whereas in IPs, heterogeneous signal intensity was seen on T2WI, which was heterogeneous and of comparable enhancement to the turbinate, and higher ADC_mean values were commonly seen. An ADC_mean cut-off point of 1.10 × 10^-3 mm²/s achieved 100% sensitivity, 90% specificity, and 90% accuracy. In addition, special features were observed that support the distinction between the two tumours, including intestinal pattern enhancement in NHL and spot-like appearance on T2WI and enhancement in IP.

CONCLUSIONS

ADC_mean was the most valuable metric for differentiating between the atypical sinonasal NHLs and IPs.

Panax notoginseng saponins alleviate damage to the intestinal barrier and regulate levels of intestinal microbes in a rat model of chronic kidney disease

Objectives

Chronic kidney disease (CKD) is a long-term condition characterized by poor prognosis and a high mortality rate. Panax notoginseng saponins (PNS) are the main active ingredient of the traditional Chinese herb Panaxnotoginseng(Burk.)F.H.Chen, which has been widely reported to have various pharmacological effects. Here, we examined the effect of PNS on renal function and the modulation of intestinal flora and intestinal barrier in a rat model of adenine-induced CKD.

Methods

Adenine was used to establish a rat model of CKD, biochemical testing, histopathologic examination, ELISA, immunohistochemical assay, western blot assay, and fecal microbiota 16s rRNA analysis was used to test the effect of PNS on CKD rats.

Results

Adenine induced a significant decrease in glomerular filtration rate, an increase in urinary protein excretion rate, and pathological damage to renal tissue in CKD rats. TNF-α, MCP-1, IL-1β, IL-18, TMAO, and endotoxin levels were increased in the blood of the model rats. Application of PNS countered the effects of adenine, restoring the above parameters to the level observed in healthy rats. In addition, activation of the inflammatory proteins NF-κB (p65) and NLRP3 and the fibrosis-associated proteins α-SMA and smad3 were inhibited in the kidneys of CKD rats. Furthermore, PNS promoted the expression of the tight junction proteins Occludin and ZO-1, increased SIgA levels, strengthened intestinal immunity, reduced mechanical damage to the intestine, was reduced levels of DAO and D-LA. Our data suggest PNS may delay CKD by restoring gut microbiota, and through the subsequent generation of a microbial barrier and modulation of microbiota metabolites.

Conclusions

In conclusion, PNS may inhibit the development of inflammation and fibrosis in the kidney tissue through regulation of intestinal microorganisms and inhibition of the activation of pro-inflammatory and pro-fibrotic proteins in the kidney.

Vascular Calcification in Chronic Kidney Disease: An Update and Perspective

Chronic kidney disease is a devastating condition resulting from irreversible loss of nephron numbers and function and leading to end-stage renal disease and mineral disorders. Vascular calcification, an ectopic deposition of calcium-phosphate salts in blood vessel walls and heart valves, is an independent risk factor of cardiovascular morbidity and mortality in chronic kidney disease. Moreover, aging and related metabolic disorders are essential risk factors for chronic kidney disease and vascular calcification. Marked progress has been recently made in understanding and treating vascular calcification in chronic kidney disease. However, there is a paucity of systematic reviews summarizing this progress, and investigating unresolved issues is warranted. In this systematic review, we aimed to overview the underlying mechanisms of vascular calcification in chronic kidney diseases and discuss the impact of chronic kidney disease on the pathophysiology of vascular calcification. Additionally, we summarized potential clinical diagnostic biomarkers and therapeutic applications for vascular calcification with chronic kidney disease. This review may offer new insights into the pathogenesis, diagnosis, and therapeutic intervention of vascular calcification.

Long‐segment restrictive tear of radial artery under ultrasound guide for arteriovenous fistula by PTA: A case report

Considerable calcification and stenosis frequently occur in the radial artery (RA) in diabetic nephropathy. PTA was performed successfully using a balloon to expand and restrictively tear the longitudinal axis of the RA. This approach seems to be a useful measure of promoting the maturation of AVF in diabetic nephropathy.

Icariin inhibits epithelial mesenchymal transition of renal tubular epithelial cells via regulating the miR-122-5p/FOXP2 axis in diabetic nephropathy rats

Epithelial mesenchymal transition (EMT) of renal tubular epithelial cells (RTECs) dominates the pathology of diabetic nephropathy (DN). microRNAs (miRNAs) can influence the fate of DN via regulation of EMT. This study aimed to analyze the role of Icariin (ICA) in EMT of RTECs, hoping to provide theoretical basis for DN management. The DN rat model was established using streptozocin, followed by ICA treatment, histopathological observation, and detection of creatinine and blood urea nitrogen. In vitro cell models were established using high glucose (HG), followed by assessment of cell proliferation, apoptosis, and migration, and E-cadherin, α-SMA, miR-122-5p, and FOXP2 expressions. Cells were transfected with miR-122-5p mimics or si-FOXP2 for joint experiments with ICA. The targeting relationship between miR-122-5p and FOXP2 was verified. ICA repaired renal dysfunctions and glomerular structure abnormities of DN rats in a dose-dependent manner. In vitro, ICA improved proliferation while suppressed migration, apoptosis, and EMT of RTECs. miR-122-5p was up-regulated in DN rats and suppressed by ICA, and miR-122-5p targeted FOXP2. miR-122-5p up-regulation or FOXP2 down-regulation reversed the protective effects of ICA on HG-induced RTECs. Overall, our finding ascertained that ICA inhibited miR-122-5p to promote FOXP2 transcription, thereby attenuating EMT of RTECs and renal injury in DN rats.

Physiological response of Kobresia pygmaea to temperature changes on the Qinghai-Tibet Plateau

BACKGROUND

The Qinghai-Tibetan Plateau is experiencing rapid climate warming, which may further affect plant growth. However, little is known about the plant physiological response to climate change.

RESULTS

Here, we select the Kobresia pygmaea, an important perennial Cyperaceae forage, to examine the physiological indices to temperature changes in different growing months. We determined the contents of malondialdehyde, proline, soluble sugars, superoxide dismutase, peroxidation, and catalase activity in leaves and roots of Kobresia pygmaea at 25℃, 10℃, 4℃ and 0℃ from June to September in 2020. The results showed that the content of osmotic adjustment substances in the leaves and roots of Kobresia pygmaea fluctuated greatly with experimental temperature in June and September. The superoxide dismutase activity in the leaves and roots of the four months changed significantly with temperatures. The peroxidation activity in the leaves was higher than that in the roots, while the catalase activity in leaves and roots fluctuates greatly during June, with a relative stable content in other months. Membership function analysis showed that higher temperatures were more harmful to plant leaves, and lower temperatures were more harmful to plant roots. The interaction of organs, growing season and stress temperature significantly affected the physiological indicators.

CONCLUSIONS

The physiological indicators of Kobresia pygmaea can actively respond to temperature changes, and high temperature can reduce the stress resistance Kobresia pygmaea. Our findings suggest that the Kobresia pygmaea has high adaptability to climate warming in the future.

A triple-classification radiomics model for the differentiation of pleomorphic adenoma, Warthin tumour, and malignant salivary gland tumours on the basis of diffusion-weighted imaging

AIM

To develop and validate a triple-classification radiomics model for the preoperative differentiation of pleomorphic adenoma (PA), Warthin tumour (WT), and malignant salivary gland tumour (MSGT) based on diffusion-weighted imaging (DWI).

MATERIALS AND METHODS

Data from 217 patients with histopathologically confirmed salivary gland tumours (100 PAs, 68 WTs, and 49 MSGTs) from January 2015 to March 2019 were analysed retrospectively and divided into a training set (n=173), and a validation set (n=44). A total of 396 radiomic features were extracted from the DWI of all patients. Analysis of variance (ANOVA) and least absolute shrinkage and selection operator (LASSO) regression were used to select radiomic features, which were then constructed using three classification models, namely, logistic regression method (LR), support vector machine (SVM), and K-nearest neighbor (KNN). The diagnostic performance of the radiomics model was quantified by the receiver operating characteristic (ROC) curve and area under the ROC curve (AUC) of the training and validation data sets.

RESULTS

The 20 most valuable features were investigated based on the LASSO regression. LR and SVM methods exhibited better diagnostic ability than KNN for multiclass classification. LR and SVM had the best performance and yielded the AUC values of 0.857 and 0.824, respectively, in the training data set and the AUC values of 0.932 and 0.912, respectively, in the validation data set of MSGT diagnosis.

CONCLUSION

DWI-based triple-classification radiomics model has predictive value in distinguishing PA, WT, and MSGT, which can be used for preoperative auxiliary diagnosis in clinical practice.

[Radiomics nomogram of MR: a prediction of cervical lymph node metastasis in laryngeal cancer]

Objective: To establish and validate a radiomics nomogram based on MR for predicting cervical lymph node metastasis in laryngeal cancer. Methods: One hundred and seventeen patients with laryngeal cancer who underwent MR examinations and received open surgery and neck dissection between January 2016 and December 2019 were included in this study. All patients were randomly divided into a training cohort (n=89) and test cohort (n=28) using computer-generated random numbers. Clinical characteristics and MR were collected. Radiological features were extracted from the MR images. Enhanced T1 and T2WI were selected for radiomics analysis, and the volume of interest was manually segmented from the Huiyihuiying radiomics cloud platform. The variance analysis (ANOVA) and the least absolute shrinkage and selection operator (LASSO) algorithm were used to reduce the dimensionality of the radiomics features in the training cohort. Then, a radiomic signature was established. The clinical risk factors were screened by using ANOVA and multivariate logistic regression. A nomogram was generated using clinical risk factors and the radiomic signature. The calibration curve and receiver operator characteristic (ROC) curve were used to confirm the nomogram's performance in the training and test sets. The clinical usefulness of the nomogram was evaluated by decision curve analysis (DCA). Furthermore, a testing cohort was used to validate the model. Results: The radiomics signature consisted of 21 features, and the nomogram model included the radiomics signature and the MR-reported lymph node status. The model showed good calibration and discrimination. The model yielded areas under the ROC curve (AUC) in the training cohort, specificity, and sensitivity of 0.930, 0.930 and 0.875. In the test cohort, the model yielded AUC, specificity and sensitivity of 0.883, 0.889 and 0.800. DCA indicated that the nomogram model was clinically useful. Conclusion: The MR-based radiomics nomogram model may be used to predict cervical lymph node metastasis of laryngeal cancer preoperatively. MR-based radiomics could serve as a potential tool to help clinicians make an optimal clinical decision.

Efficacy and safety of evocalcet in treatment of secondary hyperparathyroidism in chronic kidney disease on hemodialysis patients: A protocol for a systematic review and meta-analysis

BACKGROUND

Secondary hyperparathyroidism (SHPT) have been associated with poor health outcomes in hemodialysis patients. The cinacalcet has popularized in clinic which has efficacy but more adverse events; the novel oral calcimimetic agents evocalcet has appeared in recent years. However, it is currently unknown whether evocalcet produces more beneficial effects and fewer adverse events in patients with SHPT. The aim of this systematic review is to estimate the safety and efficacy of evocacelt.

METHODS

Only randomized controlled trials (RCT) will be included in MEDLINE, EMBASE, the Cochrane Register of Controlled Trials, and PUBMED from July 2010 to July 2020. Two reviewers will screen, select studies, extract data, and assess quality independently. The methodological quality including the risk of bias of the included studies will be evaluated using a modified assessment form, which is based on Cochrane assessment tool. Review Manager 5.3 software will be used for heterogeneity assessment, generating funnel-plots, data synthesis, subgroup analysis, and sensitivity analysis. We will use GRADE system to evaluate the quality of our evidence.

RESULTS

We will provide some more practical and targeted results investigating the effect and safety of evocalcet for SHPT on hemodialysis in the current meta-analysis.

CONCLUSION

The stronger evidence about evocalcet effect and safety will be provided for clinicians and policymakers.

ETHICS AND DISSEMINATION

Ethical approval will be unnecessary because the data being included in this systematic review come from published literature and there will be no concerns regarding privacy. Findings of this research will be disseminated in a peer-reviewed journal or conference presentations.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/N59RB.

Transmission risk of infectious droplets in physical spreading process at different times: A review

Droplets provide a well-known transmission media in the COVID-19 epidemic, and the particle size is closely related to the classification of the transmission route. However, the term "aerosol" covers most particle sizes of suspended particulates because of information asymmetry in different disciplines, which may lead to misunderstandings in the selection of epidemic prevention and control strategies for the public. In this review, the time when these droplets are exhaled by a patient was taken as the initial time. Then, all available viral loads and numerical distribution of the exhaled droplets was analyzed, and the evaporation model of droplets in the air was combined with the deposition model of droplet nuclei in the respiratory tract. Lastly, the perspective that physical spread affects the transmission risk of different size droplets at different times was summarized for the first time. The results showed that although the distribution of exhaled droplets was dominated by small droplets, droplet volume was proportional to the third power of particle diameter, meaning that the viral load of a 100 μm droplet was approximately 10⁶ times that of a 1 μm droplet at the initial time. Furthermore, the exhaled droplets are affected by heat and mass transfer of evaporation, water fraction, salt concentration, and acid-base balance (the water fraction > 98%), which lead them to change rapidly, and the viral survival condition also deteriorates dramatically. The time required for the initial diameter (d_o) of a droplet to shrink to the equilibrium diameter (d_e, about 30% of d_o) is approximately proportional to the second power of the particle diameter, taking only a few milliseconds for a 1 μm droplet but hundreds of milliseconds for a 10 μm droplet; in other words, the viruses carried by the large droplets can be preserved as much as possible. Finally, the infectious droplet nuclei maybe inhaled by the susceptible population through different and random contact routes, and the droplet nuclei with larger d_e decompose more easily into tiny particles on account of the accelerated collision in a complex airway, which can be deposited in the higher risk alveolar region. During disease transmission, the infectious droplet particle size varies widely, and the transmission risk varies significantly at different time nodes; therefore, the fuzzy term "aerosol" is not conducive to analyzing disease exposure risk. Recommendations for epidemic prevention and control strategies are: 1) Large droplets are the main conflict in disease transmission; thus, even if they are blocked by a homemade mask initially, it significantly contains the epidemic. 2) The early phase of contact, such as close-contact and short-range transmission, has the highest infection risk; therefore, social distancing can effectively keep the susceptible population from inhaling active viruses. 3) The risk of the fomite route depends on the time in contact with infectious viruses; thus, it is important to promote good health habits (including frequent hand washing, no-eye rubbing, coughing etiquette, normalization of surface cleaning), although blind and excessive disinfection measures are not advisable. 4) Compared with the large droplets, the small droplets have larger numbers but carry fewer viruses and are more prone to die through evaporation.

Identification of Complex Pneumonia during the Outbreak of COVID-19: Bacterial Pneumonia Combined with Acute Eosinophilic Pneumonia in Patients with Maintenance Hemodialysis

It is of crucial importance to diagnose patients in a timely and clear manner during the outbreak of COVID-19. Different causes of pneumonia makes it difficult to differentiate COVID-19 from others. Hemodialysis patients are a special group of people in this outbreak. We present a successfully treated case of a patient with maintenance hemodialysis from acute eosinophilic pneumonia for using meropenem when treating bacterial pneumonia, avoiding possible panic and waste of quarantine materials in dialysis centers.

BPA disrupts the cardioprotection by 17β-oestradiol against ischemia/reperfusion injury in isolated guinea pig hearts

Bisphenol A (BPA) is an environmental oestrogen or xenoestrogen (XEs). XEs represent a health risk due to their potential for endocrine disruption and ability to mimic estrogenic activity. The effects of BPA on isolated hearts under normal and ischemia/reperfusion (I/R) conditions were investigated for the first time, with a focus on the effects of BPA and 17β-oestradiol (E₂) co-administration on I/R injury. Our results indicated that BPA at 10^-7 M and 10^-5 M did not significantly affect heart rate (HR), coronary flow (CF), lactate dehydrogenase (LDH) or creatine kinase (CK) release in normal or I/R isolated hearts within the 90 min. However, E₂ exerted a protective effect against I/R injury, whereas, BPA inhibited the cardio-protective effects of E₂ on HR, CF, and LDH and CK release. Furthermore, BPA in combination with E₂ aggravated I/R injury by increasing infarct size and causing a more severe ultrastructural disruption as compared to treatment with E₂ alone. Based on our results, we conclude that BPA inhibits the cardio-protective effects of E₂ on I/R-injured hearts, despite not significantly affecting normal or I/R isolated hearts.

[Effect of Different Walking Number on Inflammation and Nutrition in Patients with Chronic Kidney Disease]

OBJECTIVE

To ivestigate the effect of daily walking number on clinical, inflammatory and nutritional indexes for patients with chronic kidney disease.

METHODS

90 non-dialysis patients with chronic kidney disease were selected and randomly divided equally into three groups, for groups A, B and C. 30 patients for group A were asked for the number of daily walk should less than 5 000 steps, while group B patients were asked for 5 000-9 999 steps of walk and group C for more than 10 000 steps. Basic treatments were given for each group of patients and basic information, clinical, inflammatory and nutritional datas of patients were collected.

RESULTS

87 patients with chronic kidney disease completed the study, with baseline data between group A, B, C (n=30, 29, 28) consistently. After 3 months of exercise, there were no significant changes on blood lipids, serum uric acid and parathyroid hormone (PTH) for three groups, with serum creatinine of three groups stably. However, in group C, hemoglobin, ferritin, transferrin saturation were found increased significantly (P<0.05). For nutritional indexes, increasing of albumin and prealbumin level were found in three groups, while significant differences were only found in group B and C (P<0.05) and group C increased most. There were no significant change on body mass index (BMI), upper arm skinfold thickness and SGA score in three groups. For inflammatory data, significant decrease of C-reactive protein (CRP) and interleukin-6 (IL-6) were only seen in group C (P<0.05).

CONCLUSION

Walking does not increase the burden of the kidney, but can improve the nutrition and clinical indicators of patients, reduce inflammation.

Effects of S906T polymorphism on the severity of a novel borderline mutation I692M in Nav 1.4 cause periodic paralysis

Hyperkalemic periodic paralysis (HyperPP) is a dominantly inherited muscle disease caused by mutations in SCN4A gene encoding skeletal muscle voltage gated Na_v 1.4 channels. We identified a novel Na_v 1.4 mutation I692M in 14 families out of the 104 genetically identified HyperPP families in the Neuromuscular Centre Ulm and is therefore as frequent as I693T (13 families out of 14 HyperPP families) in Germany. Surprisingly, in 13 families, a known polymorphism S906T was also present. It was on the affected allele in at least 10 families compatible with a possible founder effect in central Europe. All affected members suffered from episodic weakness; myotonia was also common. Compared with I692M patients, I692M-S906T patients had longer weakness episodes, more affected muscles, CK elevation and presence of permanent weakness. Electrophysiological investigation showed that both mutants had incomplete slow inactivation and a hyperpolarizing shift of activation which contribute to membrane depolarization and weakness. Additionally, I692M-S906T significantly enhanced close-state fast inactivation compared with I692M alone, suggesting a higher proportion of inactivated I692M-S906T channels upon membrane depolarization which may facilitate the initiation of weakness episodes and therefore clinical manifestation. Our results suggest that polymorphism S906T has effects on the clinical phenotypic and electrophysiological severity of a novel borderline Na_v 1.4 mutation I692M, making the borderline mutation fully penetrant.

Bacterial IgA protease-mediated degradation of agIgA1 and agIgA1 immune complexes as a potential therapy for IgA Nephropathy

Mesangial deposition of aberrantly glycosylated IgA1 (agIgA1) and its immune complexes is a key pathogenic mechanism of IgA nephropathy (IgAN). However, treatment of IgAN remains ineffective. We report here that bacteria-derived IgA proteases are capable of degrading these pathogenic agIgA1 and derived immune complexes in vitro and in vivo. By screening 14 different bacterial strains (6 species), we found that 4 bacterial IgA proteases from H. influenzae, N. gonorrhoeae and N. meningitidis exhibited high cleaving activities on serum agIgA1 and artificial galactose-depleted IgA1 in vitro and the deposited agIgA1-containing immune complexes in the mesangium of renal biopsy from IgAN patients and in a passive mouse model of IgAN in vitro. In the modified mouse model of passive IgAN with abundant in situ mesangial deposition of the agIgA-IgG immune complexes, a single intravenous delivery of IgA protease from H. influenzae was able to effectively degrade the deposited agIgA-IgG immune complexes within the glomerulus, demonstrating a therapeutic potential for IgAN. In conclusion, the bacteria-derived IgA proteases are biologically active enzymes capable of cleaving the circulating agIgA and the deposited agIgA-IgG immune complexes within the kidney of IgAN. Thus, the use of such IgA proteases may represent a novel therapy for IgAN.

Ginsenoside Rg1 inhibits angiotensin II-induced podocyte autophagy via AMPK/mTOR/PI3K pathway

Recent researches have reported the extensive pharmacological activities of Ginsenoside Rg1 including antioxidant, anti-inflammatory, and anticancer properties. Furthermore Rg1 was also shown to protect various kinds of cells from self-digestion by its anti-autophagy activity. In previous studies, angiotensin II (Ang II), a key mediator of renin-angiotensin system, has been demonstrated to contribute to the progression of renal injury including abnormal autophagy. However, whether Rg1 can relieve Ang II-induced autophagy in podocyte as well as the underlying molecular mechanism remains to be elucidated. Here, we employed Ang II-treated podocyte as a model to investigate the effect of Rg1 on autophagy and the involved signal pathways. In the present study, we found that Ang II strongly promoted autophagy in immortalized mouse podocyte cells by observing the formation of autophagosomes and detecting the expression of autophagic marker, for example, LC3-II. Notably, compared to the Ang II-treated cells, treatment with Rg1 significantly inhibited the formation of autophagosomes and expression of autophagy-related proteins in Ang II pre-treated podocyte. Meanwhile, Rg1 downregulated the activity of AMPK and GSK-3β and upregulated the activity of P70S6K in Ang II-treated podocyte. In conclusion, these findings demonstrate that Ang II promotes autophagy in podocyte, and Rg1 effectively attenuates this process through AMPK/mTOR/PI3K pathway, suggesting that Rg1 may be beneficial to alleviate podocyte injury.

Ginsenoside Rg1 reduces aldosterone-induced autophagy via the AMPK/mTOR pathway in NRK-52E cells

Aldosterone is a steroid hormone secreted from the adrenal cortex, which regulates blood pressure. Higher concentrations of aldosterone can cause several diseases, including hypertension, diabetic nephropathy and chronic kidney disease. Previous reports have demonstrated that aldosterone has a pathogenic role in renal injury via reactive oxygen species (ROS), which involves the regulation of autophagy. However, whether aldosterone can induce autophagy in renal tubular cells remains to be elucidated. In the present study, elevated autophagy was observed in rat renal tubular NRK-52E cells exposed to aldosterone, which was demonstrated by the increased number of autophagosomes, conversion of LC3-I to LC3-II and the expression of Beclin-1. The enhanced autophagy was accompanied by increased production of intracellular ROS, which was reversed by N-acetylcysteine, a specific inhibitor of ROS signaling. Furthermore, treatment with ginsenoside Rg1 reduced the aldosterone-induced autophagy and production of ROS, possibly through reducing the phosphorylation of AMPK and preserving mTOR activity. These findings demonstrated that aldosterone promoted ROS generation and increased autophagy in the NRK-52E cells. Ginsenoside Rg1 effectively relieved aldosterone-induced oxidative stress and abnormal autophagy, suggesting that Rg1 may be used as a potential therapeutic drug to inhibit the renal injury, which is induced by aldosterone.

Nutlin-3 downregulates p53 phosphorylation on serine392 and induces apoptosis in hepatocellular carcinoma cells

Drug-resistance and imbalance of apoptotic regulation limit chemotherapy clinical application for the human hepatocellular carcinoma (HCC) treatment. The reactivation of p53 is an attractive therapeutic strategy in cancer with disrupted-p53 function. Nutlin-3, a MDM2 antagonist, has antitumor activity in various cancers. The post-translational modifications of p53 are a hot topic, but there are some controversy ideas about the function of phospho-Ser³⁹²-p53 protein in cancer cell lines in response to Nutlin-3. Therefore, we investigated the relationship between Nutlin-3 and phospho-Ser³⁹²-p53 protein expression levels in SMMC-7721 (wild-type TP53) and HuH-7 cells (mutant TP53). We demonstrated that Nutlin-3 induced apoptosis through down-regulation phospho-Ser³⁹²-p53 in two HCC cells. The result suggests that inhibition of p53 phosphorylation on Ser³⁹² presents an alternative for HCC chemotherapy. [BMB Reports 2014; 47(4): 221-226]

Cobalt oxide-carbon nanosheet nanoarchitecture as an anode for high-performance lithium-ion battery

To improve the electrochemical performance of cobalt oxide owing to its inherent poor electrical conductivity and large volume expansion/contraction, Co3O4-carbon nanosheet hybrid nanoarchitectures were synthesized by a facile and scalable chemical process. However, it is still a challenge to control the size of Co3O4 particles down to ∼5 nm. Herein, we created nanosized cobalt oxide anchored 3D arrays of carbon nanosheets by the control of calcination condition. The uniformly dispersed Co3O4 nanocrystals on carbon nanosheets held a diameter down to ∼5 nm. When tested as anode materials for lithium-ion batteries, high lithium storage over 1200 mAh g(-1) is achieved, whereas high rate capability with capacity of about 390 mAh g(-1) at 10 A g(-1) is maintained through nanoscale diffusion distances and interconnected porous structure. After 500 cycles, the cobalt oxide-carbon nansheets hybrid display a reversible capacity of about 970 mAh g(-1) at 1 A g(-1). The synergistic effect between nanosized cobalt oxide and sheetlike interconnected carbon nanosheets lead to the greatly improved specific capacity and the initial Coulombic efficiency of the hybrids.

[Effect of silencing Bmi-1 expression in reversing cisplatin resistance in lung cancer cells and its mechanism]

OBJECTIVE

To investigate the effect of silencing Bmi-1 expression in reversing cisplatin resistance in human lung cancer cells and explore the possible mechanisms.

METHODS

Cisplatin-resistant A549/DDP cells with small interference RNA (siRNA)-mediated Bmi-1 expression silencing were examined for cisplatin sensitivity using MTT assay and alterations in cell cycle distribution and apoptosis with flow cytometry, and the changes in cell senescence was assessed using β-galactosidase staining. The protein expressions of Bmi-1, P14(ARF), P16(INK4a), P53, P21, Rb and ubi-H2AK119 in the cells were determined with Western blotting.

RESULTS

A549/DDP cells showed significantly higher Bmi-1 expression than A549 cells. After siRNA-mediated Bmi-1 silencing, A549/DDP cells showed significantly enhanced cisplatin sensitivity with an increased IC50 from 40.3±4.1 µmol/L to 18.3±2.8 µmol/L (P<0.01) and increased cell percentage in G0/G1 phase from (48.9±2.3)% to (78.7±7.6)% (P<0.01). Silencing Bmi-1 did not cause significant changes in the cell apoptosis rate but induced obvious senescence phenotype in A549/DDP cells with down-regulated expression of ubi-H2AK119 and up-regulated expressions of P14(ARF), P16(INK4a), P53, P21 and Rb.

CONCLUSION

Silencing Bmi-1 by RNA interference can induce cell senescence and resensitize A549/DDP cells to cisplatin possibly by regulating INK4a/ARF/Rb senescence pathway.

Ginsenoside Rg1 protects mouse podocytes from aldosterone-induced injury in vitro

AIM

Aldosterone is elevated in many diseases such as hypertension, diabetic nephropathy and chronic kidney disease, etc. The aim of this study was to investigate the effects of aldosterone on intracellular ROS production and autophagy in podocytes in vitro, and to explore the possibility of ginsenoside Rg1 (Rg1) being used for protecting podocytes from aldosterone-induced injury.

METHODS

MPC5 mouse podocyte cells were tested. Autophagosome and autophagic vacuole formation were examined under confocal microscopy with MDC and acridine orange staining, respectively. ROS were detected with flow cytometry. Malondialdehyde content and superoxide dismutase (T-SOD) activity were measured using commercial kits. The expression of LC3-II, beclin-1, SOD2 and catalase was measured by Western blotting.

RESULTS

Treatment with aldosterone (10 nmol/L) significantly increased ROS generation and the expression of SOD2 and catalase in MPC5 cells. Furthermore, treatment with aldosterone significantly increased the conversion of LC3-I to LC3-II, beclin-1 expression and autophagosome formation. Co-treatment with rapamycin (1 ng/mL) or chloroquine (10 μmol/L) further increased aldosterone-induced autophagosome formation. Co-treatment with Rg1 (80 ng/mL) effectively relieved oxidative stress and increased T-SOD activity at the early stage and subsequently decreased autophagy in aldosterone-treated podocytes. Co-treatment with 3-MA (4 mmol/L) or NAC (50 mmol/L) exerted similar effects against aldosterone-induced autophagy in podocytes.

CONCLUSION

Aldosterone enhances ROS generation and promotes autophagy in podocytes in vitro. Ginsenoside-Rg1 effectively relieves aldosterone-induced oxidative stress, thereby indirectly inhibiting aldosterone-induced podocyte autophagy.

[Management of chronic kidney disease guided by the theory of Traditional Chinese Medicine: an experimental study]

OBJECTIVE

To determine the impact of Traditional Chinese Medicine on patients with chronic kidney disease (CKD).

METHODS

A total of 225 CKD patients in an outpatient department were recruited for this study, among whom 170 received regular Western and Chinese medicine treatments (control group) and 55 received treatments guided by the theory of Traditional Chinese Medicine (experimental group). The effectiveness of the treatments was determined through a pre-post comparison.

RESULTS

Significant pre-intervention differences in age (P < 0.01), stage of glomerular filtration rate (GFR) (P = 0.007) and urine protein (P < 0.01) were found between the two groups of patients. But age, gender and proteinuria were not significant predictors on clinical outcomes of the patients in the multivariate regression models. The experimental group had a greater level of decrease in blood urea nitrogen (P < 0.01) and serum creatine (P < 0. 01) than the control group. No significant differences between the groups were found in changes of uric acid (P = 0.475), urine protein (P = 0.058), urine red cells (P = 0.577), and urine white cells (P = 0.01). A greater level of increase in estimated glomerular filtration rate was found in the experimental group compared with the control (P < 0.001). The multivariate linear regression analysis identified group (B = 0.395, P < 0.001) and stage of GFR (B = 0.165, P = 0.008) as significant predictors on the outcomes of treatment.

CONCLUSION

The treatment of CKD patients guided by the theory of Traditional Chinese Medicine can improve renal function through influencing glomerular filtration rate. The effect is more prominent than the regular treatment regime.

KB-R7943 restores endothelium-dependent relaxation induced by advanced glycosylation end products in rat aorta

OBJECTIVES

The aims of this study were to examine the effects of KB-R7943, an inhibitor of Na(+)/Ca(2+) exchanger, on impaired endothelium-dependent relaxation (EDR) induced by advanced glycosylation end products (AGE) in isolated rat aorta.

METHODS

Both acetylcholine (ACh)-induced EDR and sodium nitroprusside (SNP)-induced endothelium-independent relaxation (EIR) were measured after the rings were exposed to AGE in the absence and presence of KB-R7943.

RESULTS

Co-incubation of aortic rings with AGE (0.1 g/L) for 24 h resulted in a significant inhibition of EDR, but had no effects on EIR. After incubation of the rings in the co-presence of KB-R7943 (0.1-10 μM) with AGE for 24 h, KB-R7943 (10 μM) significantly attenuated impaired EDR. Superoxide dismutase (200 U/mL) and l-arginine (3mM) could ameliorate the impairment of EDR caused by AGE, whereas d-arginine (3mM) had no effect on EDR. Similarly, AGE decreased superoxide dismutase (SOD) activity and the release of nitric oxide (NO), and increased superoxide anion (O(2)(.-)) production in aortic tissue. KB-R7943 (10 μM) significantly decreased O(2)(.-) production and increased SOD activity and the NO release.

CONCLUSIONS

These results suggest that KB-R7943 attenuated the impairment of EDR elicited by AGE partially through scavenging oxygen free radicals.

WITHDRAWN: Isolation and Identification of a Multilineage Potential Mesenchymal Cell from Human Placenta

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Structure characterization of human RalGDS gene, and the identification of its novel variant

RalGDS is a guanine nucleotide dissociation stimulator for Ral, which is a member of the Ras GTPase superfamily that regulates cellular proliferation, differentiation and transformation by mediating multiple signal transduction pathways. RalGDS can specifically promote the conversion from an inactive GDP-bound state to an active GTP-bound state for Ral. The cDNA of human RalGDS has been cloned recently. In this paper, by comparison between the gene's genomic and cDNA seqence, we determined the structure of the gene, which showed that the reported human RalGDS transcribed from 18 exons. Furthermore, a novel variant of RalGDS that codes for a protein with a different N-terminus was cloned and identified. Northern hybridization revealed that the novel transcript was of 6.0 kb in length while the transcript previously reported is of 4.0 kb. Both transcripts were ubiquitously expressed in human adult tissues examined, albeit with different amounts. In addition, this novel transcript was proved to be caused by employment of a new exon, designated as exon 1a, instead of the one, designated as exon 1b, in the reported cDNA. Thus, the RalGDS gene consists of at least 19 exons and spanned a 44 kb region. The length between exon 1a and exon 2 was 33 kb, while the length between exon 1b and exon 2 was 8.8 kb.

Expansion of CD34(+) cells from human umbilical cord blood by FL and/or TPO gene transfected human marrow stromal cell lines

To elucidate the effect of gene transfected marrow stromal cell on expansion of human cord blood CD34(+) cells, a culture system was established in which FL and TPO genes were transfected into human stromal cell line HFCL. To establish gene transfected stromal cells co-culture system, cord blood CD34(+) cells were purified by using a magnetic beads sorting system. The number of all cells and the number of CD34(+) cells and CFC (CFU-GM and BFU-E) were counted in different culture systems. The results showed that in all 8 culture systems, SCF+IL-3+HFT manifested the most potent combination, with the number of total nucleated cells increasing by (893.3 +/-52.1)-fold, total progenitor cells (CFC) by (74.5 +/-5.2)-fold and CD34(+) cells by 15.7-fold. Maximal expansions of CFC and CD34(+) cells were observed at the end of the second week of culture. Within 14 days of culture, (78.1 +/- 5.5)-fold and (57.0 +/- 19.7)-fold increases in CFU-GM and BFU-E were obtained. Moreover, generation of LTC-IC from amplified CD34(+) cells within 28 days was found only in two combinations, i.e. SCF+IL-3+FL+TPO and SCF+IL-3+HFT, and there was no significant difference between these two groups statistically. These results suggest that human umbilical cord blood CD34(+) cells can be extensively expanded ex vivo by using gene transfected stromal cells along with cytokines.

Reversing drug resistance in the ovarian carcinoma cell line SKOV3/mdr1 in vitro by antisense oligodeoxynucleotides

OBJECTIVE

To investigate the effect of multidrug resistance gene 1 (mdr1) antisense oligodeoxynucleotides (ODNs) on reversing multidrug resistance in the drug resistant ovarian carcinoma cell line SKOV3/mdr1.

METHODS

The ovarian carcinoma cell line SKOV3 transducted with a human multidrug resistance gene (mdr1) served as the drug resistant model (SKOV3/mdr1). The mdr1 antisense ODNs was transfected into SKOV3/mdr1 cells while mediated by lipofectamine. Reverse transcription-polymerase chain reaction (RT-PCR) was used to measure the expression and the amount of the mdr1 mRNA in the cells. The positive rate and function of the mdr1 gene product P-glycoprotein (Pgp) in the mdr1 antisense ODNs treated SKOV3/mdr1 cells were determined by flow cytometry and rhodamine 123 efflux. Drug resistance in the SKOV3/mdr1 cell line was observed by MTT assay and cell colony culture.

RESULTS

The mdr1 mRNA level was decreased to about 60% of that of beta-actin after mdr1 antisense ODNs treatment. The Pgp positive rate of mdr1 antisense ODNs treated SKOV3/mdr1 cells decreased from 100% to 52.6% (P < 0.01). The intracellular rhodamine 123 retention was increased from 9.1% to 33.8% (P < 0.01). The chemoresistance to taxol decreased to 58% of SKOV3/mdr1 with mdr1 antisense ODN treatment. Compared with SKOV3/mdr1 cells in the control group, under a certain range of drug concentrations, the number of drug resistance colonies in mdr1 antisense ODNs treated SKOV3/mdr1 cells for taxol and doxorubicin decreased by 8.6 +/- 0.8 fold and 3.1 +/- 0.6 fold, respectively. Some non-specific functions during oligodeoxyncleotide treatment was also detected.

CONCLUSION

mdr1 expression in the SKOV1/mdr1 cell line was partially inhibited after mdr1 antisense ODNs treatment at the mRNA and protein level, increasing the chemotherapy sensitivity of this drug resistant ovarian carcinoma cell line.

Biological features of mesenchymal stem cells from human bone marrow

OBJECTIVE

To study the biological characteristics of mesenchymal stem cells (MSCs) from human bone marrow.

METHODS

A culture of mesenchymal stem cells was initiated from bone marrow low-density mononuclear cells separated by Percoll Centrifugation and maintained in low-glucose Dulbecco's modified Eagle's medium (DMEM) with 10% selected fetal calf serum. Cell growth pattern and its responses to cytokines were evaluated by trypan blue exclusion and MTT test, respectively. Cell cycle and surface antigenic features were analyzed by flow cytometry technique. Cytochemistry characteristics of MSCs were determined.

RESULTS

Easy-handling methods to isolate and culture expand MSCs were developed in this study. MSCs were unique in their phenotypes. They were positive for CD29, CD44, CD166, and negative for CD34, CD45, HLA-DR and Ulex europaeus. Cytochemistry evaluation showed that MSCs were homogeneously positive for acid alpha-naphthl acetate esterase (ANAE), glycogen (periodic acid Schiff reaction, PAS), and negative for acid phosphatase (ACP) and the Sudan black reaction (SB). Around 5% of them were positive for alkaline phosphatase (ALP). The cells had a population doubling time of 30 hours and cell cycle analysis showed that approximately 10% of them were in S phase. MSCs grew at significantly different rates when incubated in the presence of various recombinant human cytokines, of which interferon gamma, tumor necrosis factor alpha, stem cell factor and insulin-like growth factor promoted the proliferation of MSCs dramatically, while others tested had no effects on cell growth.

CONCLUSIONS

MSCs are a homogenous population of cells that have unique growth, phenotypical and cytochemical characteristics. Furthermore, the diverse responses of MSCs to different cytokines provide a clue for the selection of optimal expansion and maintenance of MSCs.

Protective effect of human CD40-Ig fusion protein in a murine model of acute graft-versus-host disease

OBJECTIVE

To investigate the protective effects of blocking CD40/CD40L interactions with human CD40-Ig fusion protein in a murine graft-versus-host disease model.

METHODS

Human CD40 gene extracellular region was inserted into plasmid pIG1, which contains genomic human IgG1 Fc gene. A transient vector containing CD40-Fc fusion gene was transfected into COS-7 cells. The CD40-Ig fusion protein was detected through enzyme-linked immunosorbent assay (ELISA). A constitutive vector was also generated by ligating the CD40-Fc fusion gene into pcDNA3.1 and transfecting it into CHO cells. CD40-Ig was purified by protein A affinity chromatography. SDS-PAGE, Western blot and ligand binding assay were used to identify the qualities of CD40-Ig. Murine acute graft-versus-host disease (GVHD) was induced by intravenous injection of C57BL/6J (H-2b) spleen cells into sub-lethally irradiated BALB/c (H-2d) mice. Protective effects against murine graft-versus-host disease by in vivo administration of CD40-Ig were evaluated.

RESULTS

Mammalian expression vectors pIG/40Ig and p3.1/40Ig were constructed as described above. Chimeric proteins were expressed in COS-7 and CHO cell culture supernatant and confirmed by ELISA and Western blot. SDS-PAGE showed that fusion proteins had a disulfide-bonded dimeric structure and existed as homodimer. Purified CD40-Ig could bind to CD40L. In vivo administration of CD40-Ig could prevent the development of GVHD and significantly prolong the mean survival time of mice with graft-versus-host disease.

CONCLUSIONS

These results demonstrate that CD40/CD40L interactions play an important role in the pathogenesis of graft-versus-host disease and suggest clinical potential for CD40-Ig in the prevention and treatment of human graft-versus-host disease.

[In vitro cotransfer human multidrug resistance gene (mdr-1) and dihydrofolate reductase gene (DHFR) into human CD(34)(+) progenitor cells to broaden the spectrum of drug resistance]

OBJECTIVE

To explore the feasibility of cotransferring human mdr-1 gene and DHFR gene into human CD(34)(+) progenitor cells to broaden the spectrum of drug resistance and improve the tolerance of myelosuppression following combination chemotherapy.

METHODS

The recombinant retroviral vector pSF-DIM containing mdr-1 and DHFR (L22Y) gene was constructed by introducing IRES sequence into vector FMCF which enable highly efficient gene expression in early hematopoietic cells. The retrovirus titers were raised by repeated supernatant cross infection between the amphotropic and ectropic retroviral packaging cells. Human CD(34)(+) progenitor cells were transduced by supernatant infection. Expression of P-gp was detected by flow cytometry. Integration of the foreign drug resistance gene in CD(34)(+) cells was determined by PCR. Drug resistance was evaluated by CFU-GM assay.

RESULT

Integration of the two foreign drug resistance genes was detected in the CD(34)(+) cells after pSF-DIM transduction. Compared with the untransduced group, the expression of P-gp elevated by 10.98% after gene transduction and the CFU-GM yields were significantly increased at 48 nmol/L of MTX and 10 ng/ml or 12 ng/ml of taxol (P < 0.05).

CONCLUSION

The retroviral vector pSF-DIM can mediate mdr-1 and DHFR gene integration and co-expression in human hematopoietic progenitor cells so as to broaden the spectrum of drug resistance.

Cloning and characterization of CIS 1b (cytokine inducible SH2-containing protein 1b), an alternative splicing form of CIS 1 gene

JAK-STAT pathway is essential in relaying cytokine signals and plays a vital role in cellular responses such as proliferation, differentiation and immunity. Some members of a recently found cytokine-inducible SH2 protein (CIS, =SOCS or SSI) family have proved to have negative effects on modulating JAK-STAT signaling pathway. In the present study, a novel human cDNA (CIS1b) which proved to be a variant of CIS1 gene was isolated by screen human placenta lambda gt11 cDNA library and 5'-rapid amplification of cDNA ends (RACE). Furthermore, the gene structure of CIS1 was determined by comparing the cDNA sequences of CIS1 and CIS1b to the genomic sequence in human chromosome 3p21.3. The expression patterns of CIS1b as well as CIS1 were analysed by Northern blot.