Prospective Comparison of Equations Based on Creatinine and Cystatin C for the Glomerular Filtration Rate Estimation in Chinese Renal Transplant Recipients

BACKGROUND

Currently, there is no dedicated equation to estimate glomerular filtration rate (GFR) for transplanted kidneys. This study aimed to compare the performance of serum creatinine (Scr)- and cystatin C (CysC)-based equations in Chinese renal transplant recipients.

METHODS

A total of 252 stable renal transplant recipients were enrolled in this study. The plasma clearance of ^99mTc-DTPA (rGFR) was used as a reference standard. The Scr, CysC, and rGFR of the patients were measured on the same day. The bias, precision, accuracy (percentage of estimates within 10%, 30%, and 50% of rGFR), and agreements of 8 Scr and 5 CysC eGFR equations were assessed. The factors affecting the accuracy were also evaluated.

RESULTS

Among the Scr-based equations, the Japanese Society of Nephrology-Chronic Kidney Disease Initiatives (JSN-CKDI) equation had the best overall performance with a bias of -6.2 mL/min/1.73 m², and 96.1% of its estimates were within 30% of the rGFR. For the CysC-based equations, the Filler equation had the best performance with a bias of -3.9 mL/min/1.73 m², and 93.7% of its estimates were within 30% of the rGFR. Overall, the CysC-based equations showed better performance than the Scr-based equations. In addition, significant differences were observed between bias and gender and between bias and rGFR value in some equations, whereas transplantation time and immunosuppressive regimens were not correlated with the bias.

CONCLUSION

The JSN-CKDI equation provides the best estimation of the GFR equations, and the CysC-based equations performed better than the Scr-based equations in this population.

Generation of monoclonal antibodies against MGA and comparison of their application in breast cancer detection by immunohistochemistry

Mammaglobin A (MGA) is an organ specific molecular biomarker for metastatic breast cancer diagnosis. However, there are still needs to develop optimal monoclonal antibodies (mAbs) to detect MGA expression in breast carcinoma by immunohistochemistry. In this study, we first generated mAbs against MGA. Then, we used epitope prediction and computer-assisted structural analysis to screen five dominant epitopes and identified mAbs against five epitopes. Further immunohistochemical analysis on 42 breast carcinoma specimens showed that MHG1152 and MGD785 had intensive staining mainly in membrane, while CHH11617, CHH995 and MJF656 had more intensive staining within the cytoplasm. MGA scoring results showed that MJF656 had the highest rate (92.8%) of positive staining among five mAbs, including higher staining intensity when compared with that of MHG1152 (p < 0.01) and CHH995 (p < 0.05) and the highest the mean percentage of cells stained among mAbs. Furthermore, we analyzed the relationship of positive staining rate by mAbs with patient clinical characteristics. The results suggest that MJF656 was able to detect MGA expression, especially in early clinical stage, low grade and lymph node metastasis-negative breast carcinoma. In conclusion, our study generated five mAbs against MGA and identified the best candidate for detection of MGA expression in breast cancer tissues.

Transcription factor SCIRR69 involved in the activation of brain-derived neurotrophic factor gene promoter II in mechanically injured neurons

The spinal cord injury and regeneration-related gene #69 (SCIRR69), which was identified in our screen for genes upregulated after spinal cord injury, encode a protein belonging to the cAMP response element-binding protein (CREB)/ATF family of transcription factors. Our previous study showed that SCIRR69 functions as a transcriptional activator. However, the target gene regulated by SCIRR69 and its roles in injured neurons remain unknown. In this study, we showed that SCIRR69 is widely distributed in the central nervous system. Full-length SCIRR69 is an endoplasmic reticulum-bound protein. Following mechanical injury to neurons, SCIRR69 was induced and proteolytically cleaved by site-1 and site-2 proteases, and the proteolytically cleaved SCIRR69 (p60-SCIRR69) was translocated to the nucleus where it bound to brain-derived neurotrophic factor (BDNF) gene promoter II. In addition, loss- and gain-of-function studies confirmed that SCIRR69 is involved in the regulation of BDNF expression in injured neurons. As expected, the culture supernatants of PC12 cells stably expressing p60-SCIRR69 contained higher levels of BDNF, and more remarkably promoted neurite outgrowth in a spinal cord slice culture model in vitro than the supernatants of control cells. These results suggest that SCIRR69 is a novel regulator of the BDNF gene and may play an important role in the repair and/or regeneration of damaged neural tissues by specifically activating BDNF promoter II.

Arachidonic acid: a bridge between traumatic brain injury and fracture healing

Traumatic brain injury (TBI) is associated with enhanced osteogenesis. The aim of this study was to investigate the effect of serum from TBI rats on fracture healing. Results from this study showed that the serum from TBI rats enhanced the expression of bone gamma carboxyglutamate protein (BGLAP), and promoted in vitro proliferation of MC3T3-E1 cells, a mouse osteoblastic cell line. Furthermore, gas chromatography/mass spectrometry (GC/MS) coupled with multivariate statistical analysis was used to identify the changes in global serum metabolites after TBI. We found that arachidonic acid (AA) was significantly enhanced in serum metabolites in TBI subjects, while hydroxybutyric acid, leucine, malic acid, 5-oxyproline, isocitric acid, mannose, and uric acid were reduced. Finally, we examined the effects of AA on BGLAP expression and cell proliferation in MC3T3-E1 cells. We found that BGLAP expression and proliferation of osteoblasts were positively regulated in the presence of AA. These findings suggest that the increased AA in serum after TBI may play a key role in enhancing the speed of fracture healing.

Cloning and characterization of SCIRR69: a novel transcriptional factor belonging to the CREB/ATF family

The complete cDNA sequence of a novel gene, SCIRR69 (spinal cord injury and regeneration related no. 69 gene), was obtained by RACE technique. It codes for a protein of 521 amino acid residues homologous to human CREB3l2 (also known as BBF2H7) and mouse CREB3l2. The protein contains a basic DNA binding and leucine zipper dimerization (B-ZIP) motif and a hydrophobic region representing a putative transmembrane domain, similar to the structure of other CREB/ATF transcription factors. Monoclonal antibody against SCIRR69 was developed and could recognize the SCIRR69 protein in both native and denatured forms. Constructing of SCIRR69 fusion proteins with the GAL4 DNA-binding domain disclosed that SCIRR69 functioned as a transcriptional activator and its N-terminal 60 amino acids accounted for the activation ability. SCIRR69 resides in the cytoplasm of primary neurons, whereas neuron damage by incision led to the cleavage and translocation from the cytoplasm to the nucleus. These results suggest that SCIRR69 is activated by proteolytic cleavage at the transmembrane domain in response to neuron damage and its amino-terminal cytoplasmic domain translocates into the nucleus to activate the transcription of target genes.

Relative expression of type II MAGE genes during retinoic acid-induced neural differentiation of mouse embryonic carcinoma P19 cells: a comparative real-time PCR analysis

In mammals, the type II melanoma antigen (MAGE) protein family is constituted by at least ten closely related members, but our understanding of their function in the developing nervous system remains poor. To systematically study the expression pattern of type II MAGE genes during neurogenesis, we employed mouse embryonic carcinoma P19 cells as an in vitro model for neural differentiation by retinoic acid (RA) induction. The expression of type II MAGE genes was investigated under distinct steps of differentiation by a comparative ΔΔC (T) paradigm of real-time quantitative reverse-transcription PCR (qRT-PCR). The relative levels of each gene expression at various steps of differentiation were expressed as a fold change compared with that in RA-untreated P19 cells. The results revealed that: (1) the expression of MAGE-E1, E2, and Necdin transcripts was steadily increased, and the relative levels of MAGE-D1, D2, D3, F1, G1, and H1 mRNA were fluctuantly elevated after the RA-treatment at embryoid body and neural stages; (2) during RA-treatment and subsequent differentiation, the expression of MAGE-L2 mRNA was decreased. Therefore, our results suggested that MAGE-D1, D2, D3, E1, E2, F1, G1, H1, and Necdin might be involved in the early process of neurogenesis, and MAGE-L2 connected with maintenance of pluripotency of stem cells. These studies may present some clues for a better understanding of the fundamental aspects of type II MAGE genes during neurogenesis.

Preparation and characterization of murine monoclonal antibodies against rat spinal cord injury and regeneration related protein no. 69

Spinal cord injury and regeneration related protein No. 69 (SCIRR69) is a rat transmembrane bZIP transcription factor homologous to mice and human transcription factor CREB3L2. Previous work demonstrated the N-terminal region plays a critical role in its transcriptional activity. In this study, a peptide containing 18 amino acids (5-22aa) at the N-terminus of rat SCIRR69 was synthesized and coupled to the carrier protein as immunogen. One hybridoma cell line was obtained by standard cell fusion technique, followed by enzyme-linked immunosorbent assay (ELISA) and Western blot screening. The newly developed monoclonal antibody (MAb) was designated 4B4, the isotype of which was IgG2a. Immunofluorescence and Western blotting results showed that MAb 4B4 could recognize the SCIRR69 protein in both native and denatured forms. 4B4 will be a useful tool for the functional research of SCIRR69 in future studies.

Identification and characterization of scirr1, a novel gene up-regulated after spinal cord injury

Spinal cord injury and regeneration involves transcriptional activity of many genes, of which many remain unknown. Using the rat spinal cord full- transection model, bioinformatics, cloning, expression assays, fusion proteins, and transfection techniques, we identified and characterized one such differentially expressed gene, termed scirr1 (spinal cord injury and/or regeneration related gene 1). Fourteen orthologs were found in 13 species from echinoderm to insect and human by Blast search of NCBI protein reference sequence database. However, no further information is available for these homologues. Using whole-mount in situ hybridization, mouse scirr1 mRNA was expressed temporally and spatially in accordance with the early development sequence of the central nervous system. In adult rat spinal cord, expression of scirr1 mRNA was localized to neurons of gray matter by in situ hybridization. Using immunohistochemistry, SCIRR1 protein was found to be up-regulated and expressed more highly in spinal cord neurons farther from the epicenter of injury. Although the precise function of SCIRR1 is unknown, its unique pattern of expression during CNS early development and up-regulation after spinal cord injury suggest that SCIRR1 should be involved in the succeeding injury and/or repair processes of the injured spinal cord. Also, the typical F-box and leucine-rich repeat (LRR) architecture of rat SCIRR1 indicated that it may play an important substrate recruiting role in the pleiotropic ubiquitin/proteasome pathway. All these make scirr1 a new interesting start to study the spinal cord injury and regeneration mechanism.

Identification of up-regulated genes after complete spinal cord transection in adult rats

Spinal cord injury (SCI) initiates a cascade of events and these responses to injury are likely to be mediated and reflected by changes in mRNA concentrations. As a step towards understanding the complex mechanisms underlying repair and regeneration after SCI, the gene expression pattern was examined 4.5 days after complete transection at T8-9 level of rat spinal cord. Improved subtractive hybridization was used to establish a subtracted cDNA library using cDNAs from normal rat spinal cord as driver and cDNAs from injured spinal cord as tester. By expressed sequence tag (EST) sequencing, we obtained 73 EST fragments from this library, representing 40 differentially expressed genes. Among them, 32 were known genes and 8 were novel genes. Functions of all annotated genes were scattered in almost every important field of cell life such as DNA repair, detoxification, mRNA quality control, cell cycle control, and signaling, which reflected the complexity of SCI and regeneration. Then we verified subtraction results with semiquantitative RT-PCR for eight genes. These analyses confirmed, to a large extent, that the subtraction results accurately reflected the molecular changes occurring at 4.5 days post-SCI. The current study identified a number of genes that may shed new light on SCI-related inflammation, neuroprotection, neurite-outgrowth, synaptogenesis, and astrogliosis. In conclusion, the identification of molecular changes using improved subtractive hybridization may lead to a better understanding of molecular mechanisms responsible for repair and regeneration after SCI.

Proteome analysis of up-regulated proteins in the rat spinal cord induced by transection injury

The inability of the CNS to regenerate in adult mammals propels us to reveal associated proteins involved in the injured CNS. In this paper, either thoracic laminectomy (as sham control) or thoracic spinal cord transection was performed on male adult rats. Five days after surgery, the whole spinal cord tissue was dissected and fractionated into water-soluble (dissolved in Tris buffer) and water-insoluble (dissolved in a solution containing chaotropes and surfactants) portions for 2-DE. Protein identification was performed by MS and further confirmed by Western blot. As a result, over 30 protein spots in the injured spinal cord were shown to be up-regulated no less than 1.5-fold. These identified proteins possibly play various roles during the injury and repair process and may be functionally categorized as several different groups, such as stress-responsive and metabolic changes, lipid and protein degeneration, neural survival and regeneration. In particular, over-expression of 11-zinc finger protein and glypican may be responsible for the inhibition of axonal growth and regeneration. Moreover, three unknown proteins with novel sequences were found to be up-regulated by spinal cord injury. Further characterization of these molecules may help us come closer to understanding the mechanisms that underlie the inability of the adult CNS to regenerate.

Neurons derived from PC12 cells have the potential to develop synapses with primary neurons from rat cortex

Neuron transplantation is considered to be a promising therapeutic method to replace functions lost due to central nervous system (CNS) damage. However, little is known about the extent to which implanted neuron-like cells can develop into mature neurons and acquire essential properties, and especially formation of synapses with host neurons. In this investigation we seeded PC12 cells labeled with GFP into primary cultured neurons isolated from rat cerebral cortex to build a co-culture system, and then induced the PC12 cells to differentiate into neuron-like cells with NGF. Seven days later, we observed the relationship between the PC12-derived neurons and primary neurons using FM1-43 imaging and immunoelectron microscopy, and found that GFP-labeled neurons could form typical synapses with host primary neurons. These observations showed that immigrant neurons differentiated from PC12 cells could develop into mature neurons and could form intercellular contacts with host neurons. Both the immigrant and host neurons could construct neuronal networks in vitro.

Unmatched masses in peptide mass fingerprints caused by cross-contamination: an updated statistical result

Unmatched masses are often observed in the experimental peptide mass spectra when database searching is performed with the ProFound program. Comparison between theoretical and experimental mass spectra of standard proteins shows that contamination accounts for most of the unmatched masses. In this retrospective analysis, the top 100 most probable contaminating masses, as listed in order of their probability, are statistically filtered out from 118 different experimental peptide mass fingerprinting (PMF) maps. Most of the interfering masses originate from trypsin autolysis and human keratins. Subtraction of known contaminants from raw data and using cleaner masses for searching can enhance protein identification by PMF.

Identification, characterization, and functional study of the two novel human members of the semaphorin gene family

We cloned two novel human transmembrane semaphorins, (HSA)SEMA6C and (HSA)SEMA6D, that belong to the class VI subgroup of the semaphorin family. The genes for SEMA6C and SEMA6D are mapped on chromosome 1q12-21.1 and 15q21.1, respectively. Among the adult tissues, SEMA6C is expressed only in skeletal muscle, whereas SEMA6D is expressed abundantly in kidney, brain, and placenta and moderately in the heart and skeletal muscles. During murine development, neither SEMA6C nor SEMA6D was expressed in embryonic day 10.5 (E10.5) embryos, but both were highly expressed in the areas of the lateral ventricle, the striatum, the wall of the midbrain, the pons/midbrain junction, and the choroid plexus of E13 embryos. Were neurons, neither axons nor astrocytes, highly expressed both semaphorins. Three isoforms of SEMA6C and five isoforms of SEMA6D derived from alternative splicing were identified, and their expression was regulated in a tissue- and development-dependent manner. Deletion analysis indicated that a sema domain and a PSI domain are integrally necessary for correct post-translation modification and subcellular localization. The extracellular domain of SEMA6C inhibited axonal extension of nerve growth factor-differentiated PC12 cells and induced the growth cone collapse of chicken dorsal root ganglion, rat hippocampal neurons, and rat cortical neurons in a dose-responsive manner. SEMA6D acted like SEMA6C except it had no significant effect on the growth cones of rat cortical neurons.

[Proteomic analysis of different fractions in M. tuberculosis culture]

To provide a basis of molecular genetic analysis of M. tubereulosis, the proteomic profiling was prompted. M. tuberculosis H37RV was cultured in Sauton medium at 37 degrees C for 3 weeks, harvested and fractionated into three portions: suspension filtration proteins(A), cytosol proteins(B) and membrane proteins(C). These fractions were analyzed by pH3-10 IPG gradient and SDS-PAGE. The silver-stained technigue and gel images were used. Then the image was transfered into 2-DE gel analysis Software. A part of protein sports of expression level higher from the culture filtrate fraction were identified by peptide mass fingerprinting. A total of 907, 884 and 681 protein sports were observed for A. B. C fractions in M. tuberculosis H37RV, respectively. Distribution of proteins mass for 3 fractions were principally similar, About 70.5-74.4 per cent were distributed in the ranges of Mr 10-49 kD.pI of the proteins for A, B fractions were pricipally similar, About 80.9-83.5 per cent were distributed in the ranges of pH 3.0-6.4, But the number of protein sports for C fraction distributed in the ranges of pH 7.6-10.0 were more than A, B fractions. The number of protein sports of expression level higher for A, B and C fractions were 71(7.8%), 242(27.4%), 19 (2.8%), respectively. 90 pen cent from them, pH of the proteins were distributed in the ranges of pH 3.0-6.4. 73.1 per cent for proteins mass of C fraction were distributed in the ranges of 10 kD-49 kD, which were more than A, B fractions. Nine of the proteins identified ih this study appeared to be homology or putative fanction proteins, but another five proteins were unknown. The proteomic profiling of different fractions in M. tuberculosis obtained in here will be provide a basis for detailed analysis of biology functions of the proteins.

[Effect of running granule on repairing capacity of neuro-endocrine-immunity and DNA in treating mastoplasia]

OBJECTIVE

To explore the clinical effect and therapeutic mechanism of Runing Granule (RNG) in treating mastoplasia to elucidate its pathogenesis.

METHODS

One hundred and eighty-seven patients suffering from mastoplasia were randomly divided into the RNG treated group (treated group, 147 cases), and the tabellae tamoxifen control group (control group, 40 cases). The follow-up underwent for 3 months. Before and after treatment, changes of levels of plasma neurotransmitters, serum endocrine hormone, peripheral lymphocyte unscheduled DNA synthesis, the count of T lymphocyte subsets in the luteal phase during the menstrual cycle of 104 cases were measured, their clinical effects were also observed.

RESULTS

Before treatment, these cases showed disturbances in the secretion of 5-hydroxytryptamine (5-HT), epinephrine (E), estradiol (E2), follicle stimulating hormone (FSH), luteinizing hormone (LH), and the levels of norepinephrine (NE), prolactin (PRL), inducer-helper T lymphocytes (OKT4+), suppressor T lymphocytes (OKT3+), were significantly increased, progesterone (P), testosterone (T), total T cells (OKT3+), OKT4+/OKT8+ ratio, unscheduled DNA synthesis (UDS) were obviously reduced (P < 0.05, P < 0.01) in mastoplasia patients. After treatment, RNG showed regulation on disturbances of these parameters, the curative rate of the treated group was higher than that of the control group; the metabolic disturbances of 5-HT/NE, E2/P, T, OKT3+ in the treated group were improved more significantly than those in the control group (P < 0.05). During the period of clinical observation, no obvious side effect and toxicity of RNG were found.

CONCLUSIONS

Mastoplasia is caused by the interactions among multi-factors in which the neuro-endocrine-immune network plays a key role in the pathogenesis of mastoplasia. RGN was effective in treating mastoplasia, the mechanism probably lays on the regulation of comprehensive coordination from the multi-layers, multi-links and multiple pathways in the neuro-endocrine-immunity network and elevation of internal environment-stabilizing capacity of the body.

Chromosome Segregation in Fertilized Eggs From Triploid Pacific Oysters, Crassostrea gigas (Thunberg), Following Inhibition of Polar Body 1

Chromosome segregation in fertilized eggs from triploid Pacific oysters, following inhibition of the first polar body (PB1), was studied with acetic orcein staining techniques. To block the release of PB1, fertilized eggs were treated with 0.5 mg/l of cytochalasin B (CB). Four types of segregation were observed, namely, "tripolar segregation" (54.5%), "united bipolar segregation" (12%), "separated bipolar segregation" (2.5%), and "incomplete united bipolar segregation" (4%). The remaining 23% could not be classified because of chromosome disorganization, but appeared to be variants of the above. It seemed clear that the predominant pattern that gave rise to tetraploids was united bipolar segregation, although certain separated bipolar segregations might also lead to the formation of tetraploids. The sequential events of meioses observed in CB-treated eggs are described. The asynchrony of meiotic events and possible mechanisms for the various types of chromosome segregation are discussed.