A new type of rhodium-catalyzed [5+2] cycloaddition was developed for the synthesis of seven-membered rings with diverse functionalities. The ring formation was accompanied by a 1,2-acyloxy migration event. The 5- and 2-carbon components of the cycloaddition are 3-acyloxy-1,4-enynes (ACEs) and alkynes respectively. Cationic rhodium (I) catalysts worked most efficiently for the intramolecular cycloaddition, while only neutral rhodium (I) complexes could facilitate the intermolecular reaction. In both cases, electron-poor phosphite or phosphine ligands often improved the efficiency of the cycloadditions. The scope of ACEs and alkynes was investigated in both intra- and intermolecular reactions. The resulting seven-membered ring products have three double bonds that could be selectively functionalized.
Influenza remains the single most important cause of excess disability and mortality during the winter months. In spite of widespread influenza vaccination programs leading to demonstrated cost-savings in the over 65 population, hospitalization and death rates for acute respiratory illnesses continue to rise. As a person ages, increased serum levels of inflammatory cytokines are commonly recorded (TNF-α, IL-1, IL-6). Termed “inflammaging”, this has been linked to persistent cytomegalovirus (CMV) infection and immune senescence, while increased anti-inflammatory cytokines (IL-10, TGF-β) are possibly associated with more healthy aging. Paradoxically, a shift with aging toward an anti-inflammatory (IL-10) response and decline in the IFN-γ:IL-10 ratio in influenza-challenged peripheral blood mononuclear cells is associated with a decline in the cytolytic capacity of CD8+ T cells responsible for clearing influenza virus from infected lung tissue. Thus, it is seemingly counter intuitive that the immune phenotype of healthy aging predicts a poor cell-mediated immune response and more serious outcomes of influenza. Herein we postulate a mechanistic link between the accumulation of late-stage, potentially terminally-differentiated T cells, many or most of which result from CMV infection, and the immunopathogenesis of influenza infection, mediated by granzyme B in older adults. Further, adjuvanted influenza vaccines that stimulate inflammatory cytokines and suppress the IL-10 response to influenza challenge, would be expected to enhance protection in the 65+ population.
older adults; elderly; influenza; influenza vaccine; granzyme B; inflammation; CMV
Mouse models of experimental anti-glomerular basement membrane (anti-GBM) nephritis provide an analytical tool for studying spontaneous lupus nephritis. The potential of Positron Emission Tomography (PET) was evaluated using 2-deoxy-2-[18F]fluoro-d-glucose (FDG) as a probe to monitor the progression of anti-GBM induced nephritis in a mouse model. The imaging results were compared to conventional measures of renal function and pathological changes. Serum and urinary vascular cell adhesion molecule-1 (VCAM-1) levels were used as measures of endothelial cell activation and inflammation. Following a challenge with anti-glomerular antibodies, mice exhibited peak changes in serum creatinine, proteinuria, and glomerulonephritis score at 14 days post-challenge (p.c.). In contrast, VCAM levels peaked at day 7 p.c. On dynamic PET images (0–60 min) of day 7, kidneys of the anti-GBM nephritis mice demonstrated a unique pattern of FDG uptake. Compared to the time activity curve (TAC) prior to challenge, a rightward shift was observed after the challenge. By day 10 p.c., kidney FDG uptake was lower than baseline and remained so until the study ended at 21 days p.c. During this time frame measures of renal dysfunction remained high but VCAM-1 levels declined. These changes were accompanied by an increase in kidney volume as measured by Computed Tomography (CT) and intra-abdominal fluid collection. Our results suggest that FDG-PET-CT can be used as a non-invasive imaging tool to longitudinally monitor the progression of renal disease activity in antibody mediated nephritis and the magnitude of renal FDG retention correlates better with early markers of renal inflammation than renal dysfunction.
Nonstop mRNAs pose a challenge for bacteria, because translation cannot terminate efficiently without a stop codon. The trans-translation pathway resolves nonstop translation complexes by removing the nonstop mRNA, the incomplete protein, and the stalled ribosome. P1 co-transduction experiments demonstrated that tmRNA, a key component of the trans-translation pathway, is essential for viability in Shigella flexneri. tmRNA was previously shown to be dispensable in the closely related species Escherichia coli, because E. coli contains a backup system for trans-translation mediated by the alternative release factor ArfA. Genome sequence analysis showed that S. flexneri does not have a gene encoding ArfA. E. coli ArfA could suppress the requirement for tmRNA in S. flexneri, indicating that tmRNA is essential in S. flexneri because there is no functional backup system. These data suggest that resolution of nonstop translation complexes is required for most bacteria.
We explored the desaturase activities and the correlation of fatty acid desaturases (FADS) gene single nucleotide polymorphisms (SNPs) with plasma fatty acid in coronary artery disease (CAD) patients in a Chinese Han population.
Plasma fatty acids were measured by gas chromatography in CAD patients (n = 505) and a control group (n = 510). Five SNPs in the FADS gene were genotyped with high-resolution melting (HRM) methods.
After adjustment, D6D activity, assessed as arachidonic acid (AA, C20:4n-6)/linoleic acid (LA, C18:2n-6), was higher in CAD patients (p<0.001). D9D activity, which was estimated as the ratio of palmitoleic acid (C16:1)/palmitic acid (C16:0) or oleic acid (C18:1n-9) to stearic acid (C18:0), was also increased (p<0.001). The genotype distributions of rs174537 G>T and rs174460 C>T were different between the two groups. The rs174537 T allele was associated with a lower risk of CAD [OR 0.743, 95% CI (0.624, 0.884), p = 0.001]. Carriers of the rs174460 C allele were associated with a higher risk of CAD [OR 1.357, 95% CI (1.106, 1.665), p = 0.003].
We firstly report that the rs174460 C allele is associated with a higher risk of CAD, and confirm that the rs174537 T allele is associated with a lower risk of CAD. Our results indicate that FADS gene polymorphisms are likely to influence plasma fatty acid concentrations and desaturase activities.
Metagenome analysis of the gut symbionts of three different insects was conducted as a means of comparing taxonomic and metabolic diversity of gut microbiomes to diet and life history of the insect hosts. A second goal was the discovery of novel biocatalysts for biorefinery applications. Grasshopper and cutworm gut symbionts were sequenced and compared with the previously identified metagenome of termite gut microbiota. These insect hosts represent three different insect orders and specialize on different food types. The comparative analysis revealed dramatic differences among the three insect species in the abundance and taxonomic composition of the symbiont populations present in the gut. The composition and abundance of symbionts was correlated with their previously identified capacity to degrade and utilize the different types of food consumed by their hosts. The metabolic reconstruction revealed that the gut metabolome of cutworms and grasshoppers was more enriched for genes involved in carbohydrate metabolism and transport than wood-feeding termite, whereas the termite gut metabolome was enriched for glycosyl hydrolase (GH) enzymes relevant to lignocellulosic biomass degradation. Moreover, termite gut metabolome was more enriched with nitrogen fixation genes than those of grasshopper and cutworm gut, presumably due to the termite's adaptation to the high fiber and less nutritious food types. In order to evaluate and exploit the insect symbionts for biotechnology applications, we cloned and further characterized four biomass-degrading enzymes including one endoglucanase and one xylanase from both the grasshopper and cutworm gut symbionts. The results indicated that the grasshopper symbiont enzymes were generally more efficient in biomass degradation than the homologous enzymes from cutworm symbionts. Together, these results demonstrated a correlation between the composition and putative metabolic functionality of the gut microbiome and host diet, and suggested that this relationship could be exploited for the discovery of symbionts and biocatalysts useful for biorefinery applications.
The symbiotic gut microbiome of herbivorous insects is vital for their ability to utilize and specialize on plants with very different nutrient qualities. Moreover, the gut microbiome is a significant resource for the discovery of biocatalysts and microbes with applications to various biotechnologies. We compared the gut symbionts from three different insect species to examine whether there was a relationship between the diversity and metabolic capability of the symbionts and the diet of their hosts, with the goal of using such a relationship for the discovery of biocatalysts for biofuel applications. The study revealed that the metabolic capabilities of the insect gut symbionts correlated with insect adaptation to different food types and life histories at the levels of species, metabolic pathway, and individual gene. Moreover, we showed that the grasshopper cellulase and xylanase enzymes generally exhibited higher activities than those of cutworm, demonstrating differences in capabilities even at the protein level. Together, our findings confirmed our previous research and suggested that the grasshopper might be a good target for biocatalyst discovery due to their high gut cellulytic enzyme activities.
A better understanding of the risk of local recurrence (LR) will facilitate therapeutic decision making in the management of early breast cancers. In the present study, we investigated whether telomere length in the normal breast epithelial cells surrounding the tumor is predictive of breast cancer LR; 152 women who were diagnosed with breast cancer at the Lombardi Comprehensive Cancer Center were included in this nested case–control study. Cases (patients had LR) and controls (patients had no LR) were matched on year of surgery, age at diagnosis and type of surgery. Telomere fluorescent in situ hybridization was used to determine the telomere length using formalin fixed paraffin-embedded breast tissues. Small telomere length variation (TLV), defined as the coefficient variation of telomere lengths among examined cells, in normal epithelial cells adjacent to the tumor was significantly associated with a 5-fold (95% confidence interval = 1.2–22.2) increased risk of breast cancer LR. When the subjects were categorized into quartiles, a significant inverse dose–response relationship was observed with lowest versus highest quartile odds ratio of 15.3 (Ptrend = 0.012). Patients who had large TLV had significantly better 10 year recurrence free survival rate compared with patients who had small TLV (80 versus 33%). The present study revealed that TLV in normal epithelial cells adjacent to tumor is a strong predictor of breast cancer LR. If confirmed by future studies, TLV in normal epithelial cells adjacent to tumor has the potential to become a promising biomarker for predicting breast cancer LR after breast conserving surgery.
Background and Objectives
Lupus nephritis (LN) is an ominous complication of Systemic lupus erythematosus (SLE) and the risk factors for the disease progression are not very well characterized.
Design, Setting, Participants and measurements
In a retrospective study, we evaluated the mode of presentation and outcomes of 163 consecutive patients with biopsy proven LN, who presented to our center between January 1999 and September 2008. Using stepwise logistic regression analysis we assessed risk factors independently associated with response to treatment as well as to progression to end stage renal disease (ESRD) in proliferative LN (PLN).
Ninety percent of our patients belonged to minority population. Among 122 patients with class III and IV LN (PLN), 76 patients received intravenous cyclophosphamide (IVC) and 38 mycophenolate for induction while 34 patients received IVC, and 63 mycophenolate for maintenance. Thirty six (30%) patients with PLN progressed to ESRD and 3 patients died over a mean follow-up of 37.5 months. On multivariate analysis, chronicity index (CI) (p=0.0007) and hypertension (p=0.042) positively correlated with progression to ESRD and death and CI was associated with increased probability of non-response to treatment (p=0.001). Additionally, mycophenolate as maintenance agent was associated with increased likelihood of sustained complete remission and partial remission [p=0.045].
In patients with LN, Hypertension and a high CI are independent risk factors for progression to ESRD or death. Furthermore, a high CI is associated with poor response and mycophenolate as a maintenance agent may improve the response to treatment.
lupus nephritis; outcomes; lupus; SLE; LN
Histone deacetylase (HDAC) inhibitors present an exciting new approach to activate HIV production from latently infected cells to potentially enhance elimination of these cells and achieve a cure. M344, a novel HDAC inhibitor, shows robust activity in a variety of cancer cells and relatively low toxicity compared to trichostatin A (TSA). However, little is known about the effects and action mechanism of M344 in inducing HIV expression in latently infected cells.
Using the Jurkat T cell model of HIV latency, we demonstrate that M344 effectively reactivates HIV-1 gene expression in latently infected cells. Moreover, M344-mediated activation of the latent HIV LTR can be strongly inhibited by a NF-κB inhibitor aspirin. We further show that M344 acts by increasing the acetylation of histone H3 and histone H4 at the nucleosome 1 (nuc-1) site of the HIV-1 long terminal repeat (LTR) and by inducing NF-κB p65 nuclear translocation and direct RelA DNA binding at the nuc-1 region of the HIV-1 LTR. We also found that M344 synergized with prostratin to activate the HIV-1 LTR promoter in latently infected cells.
These results suggest the potential of M344 in anti-latency therapies and an important role for histone modifications and NF-κB transcription factors in regulating HIV-1 LTR gene expression.
Currently, statins are the only drugs acting on the mammalian isoprenoid pathway. The mammalian genes in this pathway are not easily amenable to genetic manipulation. Thus, it is difficult to study the effects of the inhibition of various enzymes on the intermediate and final products in the isoprenoid pathway. In fission yeast, antifungal compounds such as azoles and terbinafine are available as inhibitors of the pathway in addition to statins, and various isoprenoid pathway mutants are also available. Here in these mutants, treated with statins or antifungals, we quantified the final and intermediate products of the fission yeast isoprenoid pathway using liquid chromatography-mass spectrometry/mass spectrometry. In hmg1-1, a mutant of the gene encoding 3-hydroxy-3-methylglutaryl coenzyme A reductase (HMGR), ergosterol (a final sterol product), and squalene (an intermediate pathway product), were decreased to approximately 80% and 10%, respectively, compared with that of wild-type cells. Consistently in wild-type cells, pravastatin, an HMGR inhibitor decreased ergosterol and squalene, and the effect was more pronounced on squalene. In hmg1-1 mutant and in wild-type cells treated with pravastatin, the decrease in the levels of farnesyl pyrophosphate and geranylgeranyl pyrophosphate respectively was larger than that of ergosterol but was smaller than that of squalene. In Δerg6 or Δsts1 cells, mutants of the genes involved in the last step of the pathway, ergosterol was not detected, and the changes of intermediate product levels were distinct from that of hmg1-1 mutant. Notably, in wild-type cells miconazole and terbinafine only slightly decreased ergosterol level. Altogether, these studies suggest that the pleiotropic phenotypes caused by the hmg1-1 mutation and pravastatin might be due to decreased levels of isoprenoid pyrophosphates or other isoprenoid pathway intermediate products rather than due to a decreased ergosterol level.
Lymphocytic choriomeningitis virus (LCMV) is a common infection of rodents first identified over eighty years ago in St. Louis, MO, U.S.A. It is best known for its application in immunological studies. The history of LCMV closely correlates with the development of modern immunology. With the use of LCMV as a model pathogen several key concepts have emerged: Major Histocompatibility Complex (MHC) restriction, T cell memory, persistent infections, T cell exhaustion and the key role of immune pathology in disease. Given the phenomenal infrastructure within this field (e.g., defined immunodominant and subdominant epitopes to all T cell receptor specificities as well as the cognate tetramers for enumeration in vivo) the study of LCMV remains an active and productive platform for biological research across the globe to this day. Here we present a historical primer that highlights several breakthroughs since the discovery of LCMV. Next, we highlight current research in the field and conclude with our predictions for future directions in the remarkable field of LCMV research.
lymphocytic choriomeningitis virus; immunology; viral immunology; immune memory; persistent infection
Although it is well known that there are mutation hot spots in mtDNA, whether there are damage hot spots remain elusive. In this study, the regional DNA damage of mitochondrial genome after ionizing radiation was determined by real-time quantitative PCR. The mtDNA damage level was found to be dose-dependent and regional unequal. The control region was the most susceptible region to oxidative damage. GGG, as an typical hole trap during charge transport, was found to be disproportionally enriched in the control region. A total of 107 vertebrate mitochondrial genomes were then analyzed to testify whether the GGG enrichment in control region was evolutionary conserved. Surprisingly, the triple G enrichment can be observed in most of the homeothermal animals, while the majority of heterothermic animals showed no triple G enrichment. These results indicated that the triple G enrichment in control region was related to the mitochondrial metabolism during evolution.
Staphylococcus aureus (S. aureus) is a major nosocomial pathogen that causes a variety of infections and toxicoses. In recent years, the percentage of rifampicin-resistant S. aureus has increased rapidly in China. The aims of this study were to analyze 1) the level of rifampicin resistance in S. aureus and its correlation with mutations in the rpoB gene, and 2) the molecular characterization of rifampicin-resistant S. aureus isolates.
88 rifampicin-resistant S. aureus isolates were collected for this study. Of the 88 isolates, 83 (94.3%) were high-level rifampicin resistant (MIC≥8 mg/L) while the remaining 5 isolates (5.7%) had a low-level resistance to rifampicin (MIC, 2 to 4 mg/L). Four amino acid substitutions were found in the 88 isolates, which were 481His/Asn (95.5%), 466Leu/Ser (87.5%), 477Ala/Asp (6.8%) and 486Ser/Leu (4.5%) respectively. All mutations were found to be present in cluster I of the rpoB gene. The low-level resistant isolates were found to have only one mutation, while the high-level resistant isolates had at least two or more mutations. The most common multiple mutations were 481His/Asn+466Leu/Ser(92.8%,77/83). The other multiple mutations found were 481His/Asn+477Ala/Asp (6.0%,5/83), and 481His/Asn+466Leu/Ser+477Ala/Asp (1.2%,1/83). Out of 28 high-level rifampicin-resistant S. aureus isolates, three molecular types were found, namely, ST239-MRSA-III-spa t030 (25/28, 89.3%), ST239-MRSA-III-spa t021 (2/28, 7.1%), and ST239-MRSA-III-spa t045 (1/28, 3.6%).
Rifampicin resistance in S. aureus was closely associated with mutations in the rpoB gene. High-level rifampicin-resistant S. aureus is one of the most important features in Anhui Provincial Hospital, and high-level rifampicin resistance in S. aureus is associated with multiple mutations of rpoB gene. The prevalence of high-level rifampicin-resistant S. aureus in Anhui may be associated with the spread of the ST239-MRSA III-spa t030 clone.
Staphylococcus aureus; MRSA; Rifampicin resistance; rpoB gene; MLST
Mutations/deletions of the tumor suppressor phosphatase and tensin homolog PTEN, results in PI3K/Akt pathway hyperactivation and potentially alters oncogenic responses to targeted receptor tyrosine kinase inhibitors. We previously showed that hepatocyte growth factor (HGF):c-Met pathway inhibition decreases tumor growth and oncogenic signaling responses in PTEN-null/Met+ gliomas. Here we utilize two tet-on PTENwt-inducible glioma cell lines and xenograft models to examine the influence of PTEN on oncogenic signaling responses to HGF:c-Met pathway inhibitors. Reconstitution of PTEN inhibited Akt by >80% and inhibited cell growth by ~70–75 % in both cell lines in vitro. C-Met inhibition alone inhibited in vitro cell growth by ~80–85 % and the magnitude of growth inhibition was not altered by combining PTEN reconstitution with c-Met inhibition. Combining PTEN reconstitution with Met inhibition arrested a higher percentage of cells in G1/G0 phase of the cell cycle when compared to either PTEN reconstitution or c-Met inhibition alone. Both PTEN reconstitution alone and inhibiting autocrine HGF:c-Met signaling alone, using anti-HGF mAb, robustly inhibited the growth of subcutaneous and intracranial glioma xenografts. Combining anti-HGF therapy with PTEN reconstitution did not significantly alter the magnitude of xenograft growth inhibition. Semi-quantitative immunohistopathological analyses revealed that the inhibition of glioma xenograft angiogenesis and cell proliferation by anti-HGF mAb was greatest in conjunction with PTEN reconstitution. In contrast, xenograft cell apoptosis was greatest in response to anti-HGF therapy alone and PTEN reconstitution abrogated the apoptotic response to anti-HGF therapy. These results provide new insights into how PTEN modulates glioma responses to the inhibition of HGF:c-Met signaling and possibly other receptor tyrosine kinase pathways.
hepatocyte growth factor; Akt; xenograft; apoptosis; angiogenesis
We performed a genomewide screen for altered sensitivity to antifungal drugs, including clotrimazole and terbinafine, that target ergosterol biosynthesis using a Schizosaccharomyces pombe gene deletion library consisting of 3,004 nonessential haploid deletion mutants. We identified 109 mutants that were hypersensitive and 11 mutants that were resistant to these antifungals. Proteins whose absence rendered cells sensitive to these antifungals were classified into various functional categories, including ergosterol biosynthesis, membrane trafficking, histone acetylation and deacetylation, ubiquitination, signal transduction, ribosome biosynthesis and assembly, regulation of transcription and translation, cell wall organization and biogenesis, mitochondrion function, amino acid metabolism, nucleic acid metabolism, lipid metabolism, meiosis, and other functions. Also, proteins whose absence rendered cells resistant to these antifungals were classified into functional categories including mitochondrion function, ubiquitination, membrane trafficking, cell polarity, chromatin remodeling, and some unknown functions. Furthermore, the 109 sensitive mutants were tested for sensitivity to micafungin, another antifungal drug that inhibits (1,3)-β-d-glucan synthase, and 57 hypersensitive mutants were identified, suggesting that these mutants were defective in cell wall integrity. Altogether, our findings in fission yeast have shed light on molecular pathways associated with the cellular response to ergosterol biosynthesis inhibitors and may provide useful information for developing strategies aimed at sensitizing cells to these drugs.
Non-invasive monitoring of disease progression in kidney disease is still a major challenge in clinical practice. In vivo near-infrared (NIR) imaging provides a new tool for studying disease mechanisms and non-invasive monitoring of disease development, even in deep organs. The LI-COR IRDye® 800CW RGD optical probe (RGD probe) is a NIR fluorophore, that can target integrin alpha v beta 3 (αvβ3) in tissues.
This study aims to monitor renal disease progression in an anti-glomerular basement membrane (GBM) nephritis mouse model.
Anti-GBM nephritis was induced in 129x1/svJ mice by anti-GBM serum challenge. The expression of integrin αvβ3 in the diseased kidney was examined by immunohistochemistry and quantitative polymerase chain reaction. The RGD probe and control fluorophores, the 800CW dye, and the BSA-conjugated 800CW dye, were administered into anti-GBM nephritic mice. LI-COR Pearl® Impulse imaging system was used for in vivo imaging; while ex vivo organ imaging was acquired using the MaestroTM imaging system.
Kidney tissue from anti-GBM nephritic mice showed higher levels of integrin αvβ3 expression at both the protein and the mRNA level compared to normal mice. The RGD probe allowed in vivo renal imaging and the fluorescent signal could be specifically captured in the diseased kidneys up to 14 days, reflecting longitudinal changes in renal function.
The infrared RGD molecular probe that tracks integrin expression can be successfully used to monitor renal disease progression following immune-mediated nephritis.
Identification of natural and anthropogenic events in the past is important for studying their patterns and mechanisms; and sensitive proxies in marine sediments are more reliable for identifying these events than those in terrestrial sediments, which are usually disturbed by human activities. Since the main source materials for the sediments in the Northern Yellow Sea Mud are transported by the Yellow River, sedimentary characteristics can be used to reconstruct the historical events that occurred in the Yellow River Valley. In the present study, by analyzing sorting coefficient of grain size in a 250-year sediment core from the Northern Yellow Sea Mud, we identified several major historical events: the Haiyuan Earthquake in AD 1920 and several times of relocation of the Yellow River estuary. The proxy has the potential of detecting and reconstructing historical events; in combination with historical archives, they also provide an accurate dating method.
Chronic hepatitis B virus (HBV) infection poses a serious public health problem in many parts of the world. Presently, even with proper joint immunoprophylaxis, approximately 10-15% of newborns from HBV carrier mothers suffer from HBV infection through intrauterine transmission. One of the risk factors is the level of maternal viraemia. Telbivudine is a synthetic thymidine nucleoside analogue with activity against HBV. A few studies have evaluated the efficacy of telbivudine in preventing intrauterine HBV infection during late pregnancy. So we conducted this meta-analysis to arrive at an evidence-based conclusion. We searched Medline/PubMed, EMBASE, Cochrane Library, Web of Knowledge and China Biological Medicine Database from January 1990 to December 2011. Relative risks (RR) of the seropositivity rates for hepatitis B surface antigen (HBsAg) and HBV DNA in newborns and infants were studied. Mean differences (MD) in maternal HBV DNA levels were reviewed. Finally two randomised controlled trials (RCTs) and four non-randomised controlled trials (NRCTs) were left for analysis which included 576 mothers in total, of whom 306 received telbivudine treatment and 270 did not receive any drug. All newborns received hepatitis B vaccine (HBVac) and hepatitis B immunoglobulin (HBIG) after birth. The seropositivity rate for HBsAg or HBV DNA was significantly lower in the telbivudine group, both at birth and at 6–12 months follow up. Meanwhile, maternal HBV DNA levels prior to delivery were significantly lower in the telbivudine group. In addition, the frequency of serum creatine kinase (CK) elevation was similar in the two groups. Our meta-analysis provides preliminary evidence that telbivudine application in late pregnancy is effective in the interruption of intrauterine HBV infection, with no significant adverse effects or complications. More high quality, well-designed, double-blinded, randomised controlled and large size clinical trials are needed for further investigation and more convincing results in the future.
Hepatitis B virus; Telbivudine; Intrauterine transmission; Pregnanc
Native mammalian extracellular matrix (ECM) has been made in various forms including particles, sheet and mesh which are appropriate for site-specific applications. The ECM particles are usually created by homogenization method and have a wider size distribution. This needs to be improved to produce more uniform ECM particles. In present study, we had successfully developed a method for preparing particulate acellular dermal matrix (PADM) in different gauges. The resultant PADM was approaching a rectangular parallelepiped or cubic shape, with a better or narrower size distribution than other ECM particles in previous reports. It also retained ultrastructure and functional molecules of native ECM. In vivo performances were evaluated after implantation of PADM in an acute full-thickness skin defect wound in rats. Histological analysis showed that allogeneic PADM used as dermal regeneration template could facilitate maturation and improving collagen bundle structure of regenerated dermis at the endpoint of 20 weeks post-surgery. The PADM could be used for further investigation in analyzing the impacts of cellularly and/or molecularly modified PADM on soft tissue regeneration.
Lung tumors from smokers as well as lung tumors from mice exposed to tobacco carcinogens such as 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK), often carry mutations in K-ras, which activates downstream-signaling pathways such as PI3K/AKT/mTOR pathway. Mice with genetic deletion of one of three isoforms of AKT were used to investigate the role of AKT in mutant K-ras-induced lung tumorigenesis in mice. Although deletion of Akt1 or Akt2 decreased NNK-induced lung tumor formation by 90%, deletion of Akt2 failed to decrease lung tumorigenesis in two other mouse models driven by mutant K-ras. Genetic mapping showed that Akt2 was tightly linked to the cytochrome P450 Cyp2a locus on chromosome 7. Consequently, targeted deletion of Akt2 created linkage to a strain-specific Cyp2a5 polymorphism that decreased activation of NNK in vitro. Mice with this Cyp2a5 polymorphism had decreased NNK-induced DNA adduct formation in vivo and decreased NNK-induced lung tumorigenesis. These studies support human epidemiological studies linking CYP2A polymorphisms with lung cancer risk in humans and highlight the need to confirm phenotypes of genetically engineered mice in multiple mouse strains.
Ischemic acute kidney injury (AKI) triggers an inflammatory response which exacerbates injury that requires increased expression of endothelial adhesion molecules. To study this further, we used in situ hybridization, immunohistology, and isolated endothelial cells, and found increased Toll-like receptor 4 (TLR4) expression on endothelial cells of the vasa rectae of the inner stripe of the outer medulla of the kidney 4 h after reperfusion. This increase was probably due to reactive oxygen species, known to be generated early during ischemic AKI, because the addition of hydrogen peroxide increased TLR4 expression in MS1 microvascular endothelial cells in vitro. Endothelial TLR4 may regulate adhesion molecule (CD54 and CD62E) expression as they were increased on endothelia of wild-type but not TLR4 knockout mice in vivo. Further, the addition of high-mobility group protein B1, a TLR4 ligand released by injured cells, increased adhesion molecule expression on endothelia isolated from wild-type but not TLR4 knockout mice. TLR4 was localized to proximal tubules in the cortex and outer medulla after 24 h of reperfusion. Thus, at least two different cell types express TLR4, each of which contributes to renal injury by temporally different mechanisms during ischemic AKI.
acute kidney injury; endothelium; inflammation; ischemiat–reperfusion
Over the past decades, many studies have used data mining technology to predict the 5-year survival rate of colorectal cancer, but there have been few reports that compared multiple data mining algorithms to the TNM classification of malignant tumors (TNM) staging system using a dataset in which the training and testing data were from different sources. Here we compared nine data mining algorithms to the TNM staging system for colorectal survival analysis.
Two different datasets were used: 1) the National Cancer Institute's Surveillance, Epidemiology, and End Results dataset; and 2) the dataset from a single Chinese institution. An optimization and prediction system based on nine data mining algorithms as well as two variable selection methods was implemented. The TNM staging system was based on the 7th edition of the American Joint Committee on Cancer TNM staging system.
When the training and testing data were from the same sources, all algorithms had slight advantages over the TNM staging system in predictive accuracy. When the data were from different sources, only four algorithms (logistic regression, general regression neural network, Bayesian networks, and Naïve Bayes) had slight advantages over the TNM staging system. Also, there was no significant differences among all the algorithms (p>0.05).
The TNM staging system is simple and practical at present, and data mining methods are not accurate enough to replace the TNM staging system for colorectal cancer survival prediction. Furthermore, there were no significant differences in the predictive accuracy of all the algorithms when the data were from different sources. Building a larger dataset that includes more variables may be important for furthering predictive accuracy.
We investigated serum soluble CD163 (sCD163) levels for use in the diagnosis, severity assessment, and prognosis of sepsis in the critical ill patients and compared sCD163 with other infection-related variables.
During july 2010 and April 2011, serum was obtained from 102 sepsis patients (days 1, 3, 5, 7, and 10 after admission to an ICU) and 30 systemic inflammatory response syndrome (SIRS) patients with no sepsis diagnosed. Serum levels of sCD163, procalcitonon (PCT), and C reactive protein (CRP) were determined respectively. Sequential organ failure assessment (SOFA) scores for sepsis patients were also recorded. Then evaluated their roles in sepsis.
The sCD163 levels were 0.88(0.78–1.00)ug/mL for SIRS patients, 1.50(0.92–2.00)ug/mL for moderate sepsis patients, and 2.95(2.18–5.57)ug/mL for severe sepsis patients on day1. The areas under the ROC curves for sCD163, CRP, and PCT for the diagnosis of sepsis were, respectively, 0.856(95%CI: 0.791–0.921), 0.696(95%CI: 0.595–0.797), and 0.629(95%CI: 0.495–0.763), At the recommended cut-off 1.49 ug/mL for sCD163, the sensitivity is 74.0% with 93.3% specificity. Based on 28-day survivals, sCD163 levels in the surviving group stay constant, while they tended to gradually increase in the non-surviving group.The area under the ROC curve for sCD163 for sepsis prognosis was 0.706(95%CI 0.558–0.804). Levels of sCD163 with cut-off point >2.84 ug/mL have sensitivity of 55.8.0%, specificity 80.4%.Common risk factors for death and sCD163 were included in multivariate logistic regression analysis; the odds ratios (OR) for sCD163 and SOFA scores for sepsis prognosis were 1.173 and 1.396, respectively (P<0.05). Spearman rank correlation analysis showed that sCD163 was weakly, but positively correlated with CRP, PCT, and SOFA scores (0.2< r <0.4, P<0.0001), but not with leukocyte counts (r <0.2, P = 0.450).
Serum sCD163 is superior to PCT and CRP for the diagnosis of sepsis and differentiate the severity of sepsis. sCD163 levels were more sensitive for dynamic evaluations of sepsis prognosis. Serum sCD163 and SOFA scores are prognostic factors for sepsis.