p53 is a key regulator of cell growth and death by controlling cell cycle progression and apoptosis under conditions of stress such as DNA damage or oncogenic stimulation. As these processes are critical for cell function and inhibition of tumor development, p53 regulatory pathways are strictly monitored in cells. Recently, it was recognized that nucleolar proteins, including nucleophosmin/B23, ribosomal protein L11, and alternate reading frame (ARF), form the nucleolus-ARF-murine double minute 2 (MDM2) axis in p53 regulatory pathways, which increases p53 stability by suppressing the activity of MDM2. In this work, we show that nucleolar protein glioma tumor-suppressor candidate region gene 2 (GLTSCR2) translocates to the nucleoplasm under ribosomal stress, where it interacts with and stabilizes p53 and inhibits cell cycle progression without the involvement of the major upstream p53 regulator, ARF. Furthermore, ectopic expression of GLTSCR2 significantly suppressed growth of cancer cells in a xenograft animal model via p53-dependent pathway. Our data identify GLTSCR2 as a new member of the nucleolus–nucleoplasmic axis for p53 regulation. ARF-independent direct regulation of p53 by GLTSCR2 may be a key mechanism and therapeutic target for cell death or growth inhibition when nucleolus-ARF-p53 pathways are inactivated by genetic or epigenetic modifications of ARF, which are the second most common types of genetic change observed in human cancers.
GLTSCR2; p53; tumor suppressor; nucleolus
The aim of this study was to correlate the apparent diffusion coefficient (ADC) value of breast cancer with prognostic factors.
335 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) and ductal carcinoma in situ (DCIS) who underwent breast MRI with diffusion-weighted imaging were included in this study. ADC of breast cancer was calculated using two b factors (0 and 1000 s mm–2). Mean ADCs of IDC NOS and DCIS were compared and evaluated. Among cases of IDC NOS, mean ADCs were compared with lymph node status, size and immunochemical prognostic factors using Student's t-test. ADC was also correlated with histological grade using the Kruskal–Wallis test.
Mean ADC of IDC NOS was significantly lower than that of DCIS (p<0.001). However, the mean ADC of histological grade of IDC NOS was not significantly different (p=0.564). Mean ADC of oestrogen receptor (ER)-positive or progesterone receptor (PR)-positive cancer was significantly lower than that of ER-negative or PR-negative cancer (p=0.003 vs
p=0.032). Mean ADC of Ki-67 index-positive cancer was significantly lower than that of Ki-67 index-negative cancer (p=0.028). Mean ADC values of cancers with increased microvascular density (MVD) were significantly lower than those of cancer with no MVD increase (p=0.009). No correlations were observed between mean ADC value and human growth factor receptor 2 expression, tumour size and lymph node metastasis.
Low ADC value was correlated with positive expression of ER, PR, increased Ki-67 index, and increased MVD of breast cancer.
Using the Los Angeles Family and Neighborhood Survey (L.A.FANS-2; n = 1610), we explore the link between Mexican immigrant acculturation, diet, exercise and obesity. We distinguish Mexican immigrants and 2nd generation Mexicans from 3rd+ generation whites, blacks and Mexicans. First, we examine variation in social and linguistic measures by race/ethnicity, duration of residence and immigrant generation. Second, we consider the association between acculturation, diet and exercise. Third, we evaluate the degree to which acculturation, diet, exercise, and socioeconomic status explain the association between race/ethnicity, immigrant exposure to the US (duration since immigration/generation), and adult obesity. Among immigrants, we find a clear relationship between acculturation measures, exposure to the US, and obesity-related behaviors (diet and exercise). However, the acculturation measures do not clearly account for the link between adult obesity, immigrant duration and generation, and race/ethnicity.
Immigration; Health; Acculturation; Obesity; USA; Mexican; Diet; Exercise
Over the last decade, there has been increased attention to the role of earlier HIV testing in the United States. Our objective was to determine if this has translated into changes in the proportion of inpatients with advanced disease at the time of initial HIV diagnosis. We identified inpatients discharged with a new diagnosis of HIV infection or AIDS between 1994 and 2004 at two academic medical centers. We examined trends in initial CD4 count at diagnosis over three time periods: 1994–1996, 1997–2000 and 2001–2004. Between 1994 and 2004, 235 inpatients were newly diagnosed with HIV infection or AIDS in the two centers. For the 217 patients with available CD4 count data, the median initial CD4 count was 41/μl (interquartile range 19–138/μl). Of the 217 patients, 184(85%) had CD4 ≤200/μl and 119/217 (55%) had CD4 ≤50/μl. There were no significant differences in median CD4 count by time period. A large majority of inpatients with newly diagnosed HIV infection at two academic medical centers between 1994 and 2004 had signs of advanced immunodeficiency. Over this recent 11-year period there was no evidence that inpatients with a new HIV diagnosis were identified at earlier stages of disease.
HIV infections/testing; HIV infections/epidemiology; HIV infections/diagnosis
This study aims to: (1) document the prevalence of hepatitis C virus (HCV) among methadone maintenance treatment (MMT) patients in Kunming and Shanghai; (2) examine risk factors for HCV by comparing those who tested positive with those who were negative and (3) examine if HCV serostatus is related to attitudes toward MMT.
Using data collected from 306 patients admitted to MMT in 2009–2010 in Shanghai and Kunming, we compared HCV-positive and HCV-negative patients (based on clinical records) on their HCV knowledge and risk behaviors and attitudes toward MMT.
The HCV seropositive rate was 53.3% (51.3% in Shanghai and 55.5% in Kunming) and a majority of patients did not know their serostatus. Patients scored on average fewer than 6 correct out of the 20 items in the HCV knowledge questionnaire. Recent injection use and length of opiate use were strong predictors of HCV status, while no differences were found between HCV-positive and HCV-negative individuals in sexual risks or HCV knowledge. Both groups expressed similar views toward MMT.
The high HCV prevalence and the general lack of knowledge about HCV infection, transmission and treatment suggest the need to provide HCV education and health promotion programs among patients in MMT.
communicable diseases; health services; public health
The hetero-hexamer of the eukaryotic minichromosome maintenance (MCM) proteins plays an essential role in replication of genomic DNA. The ring-shaped Mcm2-7 hexamers comprising one of each subunit show helicase activity in vitro, and form double-hexamers on DNA. The Mcm4/6/7 also forms a hexameric complex with helicase activity in vitro.
We used an Escherichiai coli expression system to express various domains of Schizosaccharomyces pombe Mcm4, 6 and 7 in order to characterize their domain structure, oligomeric states, and possible inter-/intra-subunit interactions. We also successfully employed a co-expression system to express Mcm4/6/7 at the same time in Escherichiai coli, and have purified functional Mcm4/6/7 complex in a hexameric state in high yield and purity, providing a means for generating large quantity of proteins for future structural and biochemical studies.
Based on our results and those of others, models were proposed for the subunit arrangement and architecture of both the Mcm4/6/7 hexamer and the Mcm2-7 double-hexamer.
Cell cycle proteins; DNA-binding proteins; Recombinant proteins; Protein binding; Protein oligomerization; Schizosaccharomyces pombe; Escherichiai coli
Activating mutations of Fms-like tyrosine kinase 3 (FLT3) constitute a major driver in the pathogenesis of acute myeloid leukaemia (AML). Hence, pharmacological inhibitors of FLT3 are of therapeutic interest for AML.
The effects of inhibition of FLT3 activity by a novel potent FLT3 inhibitor, BPR1J-097, were investigated using in vitro and in vivo assays.
The 50% inhibitory concentration (IC50) of BPR1J-097 required to inhibit FLT3 kinase activity ranged from 1 to 10 n, and the 50% growth inhibition concentrations (GC50s) were 21±7 and 46±14 n for MOLM-13 and MV4-11 cells, respectively. BPR1J-097 inhibited FLT3/signal transducer and activator of transcription 5 phosphorylation and triggered apoptosis in FLT3-driven AML cells. BPR1J-097 also showed favourable pharmacokinetic property and pronounced dose-dependent tumour growth inhibition and regression in FLT3-driven AML murine xenograft models.
These results indicate that BPR1J-097 is a novel small molecule FLT-3 inhibitor with promising in vivo anti-tumour activities and suggest that BPR1J-097 may be further developed in preclinical and clinical studies as therapeutics in AML treatments.
acute myeloid leukaemia; FLT3; FLT3-ITD; MOLM-13; MV4-11; kinase inhibitor
This study aims to assess the diagnostic accuracy of a single vendor commercially available CT perfusion (CTP) software in predicting stroke. A retrospective analysis on patients presenting with stroke-like symptoms within 6 h with CTP and diffusion-weighted imaging (DWI) was performed. Lesion maps, which overlays areas of computer-detected abnormally elevated mean transit time (MTT) and decreased cerebral blood volume (CBV), were assessed from a commercially available software package and compared to qualitative interpretation of color maps. Using DWI as the gold standard, parameters of diagnostic accuracy were calculated. Point biserial correlation was performed to assess for relationship of lesion size to a true positive result. Sixty-five patients (41 females and 24 males, age range 22–92 years, mean 57) were included in the study. Twenty-two (34 %) had infarcts on DWI. Sensitivity (83 vs. 70 %), specificity (21 vs. 69 %), negative predictive value (77 vs. 84 %), and positive predictive value (29 vs. 50 %) for lesion maps were contrasted to qualitative interpretation of perfusion color maps, respectively. By using the lesion maps to exclude lesions detected qualitatively on color maps, specificity improved (80 %). Point biserial correlation for computer-generated lesions (Rpb = 0.46, p < 0.0001) and lesions detected qualitatively (Rpb = 0.32, p = 0.0016) demonstrated positive correlation between size and infarction. Seventy-three percent (p = 0.018) of lesions which demonstrated an increasing size from CBV, cerebral blood flow, to MTT/time to peak were true positive. Used in isolation, computer-generated lesion maps in CTP provide limited diagnostic utility in predicting infarct, due to their inherently low specificity. However, when used in conjunction with qualitative perfusion color map assessment, the lesion maps can help improve specificity.
CT perfusion; Stroke; Diagnostic accuracy; CT perfusion software
Autism is a neurodevelopmental disorder marked by social skills and communication deficits and interfering repetitive behavior. Intellectual disability often accompanies autism. In addition to behavioral deficits, autism is characterized by neuropathology and brain overgrowth. Increased intracranial volume often accompanies this brain growth. We have found that the Alzheimer’s disease (AD) associated amyloid-β precursor protein (APP), especially its neuroprotective processing product, secreted APP α, is elevated in persons with autism. This has led to the “anabolic hypothesis” of autism etiology, in which neuronal overgrowth in the brain results in interneuronal misconnections that may underlie multiple autism symptoms. We review the contribution of research in brain volume and of APP to the anabolic hypothesis, and relate APP to other proteins and pathways that have already been directly associated with autism, such as fragile X mental retardation protein, Ras small GTPase/extracellular signal-regulated kinase, and phosphoinositide 3 kinase/protein kinase B/mammalian target of rapamycin. We also present additional evidence of magnetic resonance imaging intracranial measurements in favor of the anabolic hypothesis. Finally, since it appears that APP’s involvement in autism is part of a multi-partner network, we extend this concept into the inherently interactive realm of epigenetics. We speculate that the underlying molecular abnormalities that influence APP’s contribution to autism are epigenetic markers overlaid onto potentially vulnerable gene sequences due to environmental influence.
Alzheimer’s-autism continuum; anabolic hypothesis; neurite overgrowth; cranial volume
To determine whether age-standardized brain morphometric and cognitive profiles differ in young-old (aged 60–75 years) and very-old (aged 80–91 years) patients with Alzheimer disease (AD).
Using a case-control retrospective design, we compared hippocampal volume and cortical gray matter thickness in areas known to be affected by AD in 105 patients with AD and 125 healthy control (HC) participants divided into young-old and very-old subgroups. Brain morphometric and cognitive scores of the AD groups were standardized to their respective age-appropriate HC subgroup and then compared.
Several cognitive domains (executive function, immediate memory, and attention/processing speed) were less abnormal in the very old with AD than in the young old with AD. Similarly, the very old with AD showed less severe cortical thinning than the young old with AD in the left posterior cingulate cortex, right lateral temporal cortex, and bilateral parietal cortex and in overall cortical thickness. This effect is partially explained by an age-related decrease in cortical thickness in these brain regions in the HC participants.
The typical pattern of AD-related cognitive and morphometric changes seen in the young old appear to be less salient in the very old. Thus, mild cases of AD in the very old may go undetected if one expects to see the prototypical pattern and severity of cognitive or brain changes that occur in the young old with AD. These results underscore the importance of interpreting neuropsychological test performance and morphometric brain measures in reference to the individual's age. Neurology® 2011;77:713–721
Thauera aminoaromatica strain MZ1T, an isolate belonging to genus Thauera, of the family Rhodocyclaceae and the class the Betaproteobacteria, has been characterized for its ability to produce abundant exopolysaccharide and degrade various aromatic compounds with nitrate as an electron acceptor. These properties, if fully understood at the genome-sequence level, can aid in environmental processing of organic matter in anaerobic cycles by short-circuiting a central anaerobic metabolite, acetate, from microbiological conversion to methane, a critical greenhouse gas. Strain MZ1T is the first strain from the genus Thauera with a completely sequenced genome. The 4,496,212 bp chromosome and 78,374 bp plasmid contain 4,071 protein-coding and 71 RNA genes, and were sequenced as part of the DOE Community Sequencing Program CSP_776774.
Thauera aminoaromatica; MZ1T; genome
Microglia are immune effector cells in the CNS and their activation, migration, and proliferation play crucial roles in brain injuries and diseases. We examined the role of iPLA2 in the regulation of microglia chemotaxis toward ADP. Inhibition of iPLA2 by BEL or iPLA2 knock-down exerted a significant inhibition on PI3K activation and chemotaxis. Further examination revealed that iPLA2 knock-down abrogated Src activation which is required for PI3K activation and chemotaxis. Colocalization studies demonstrated that cSrc-GFP was retained in the endosomal recycling compartment (ERC) in iPLA2 knock-down cells, but addition of arachidonic acid (AA) could restore cSrc trafficking to the plasma membrane by allowing the formation/release of recycling endosomes associated with cSrc-GFP. Using BODIPY-AA, we showed that AA is selectively enriched in recycling endosomes. These results suggest that AA is required for the cSrc trafficking to the plasma membrane by controlling the formation/release of recycling endosomes from the ERC.
Phospholipase A2; Arachidonic acid; chemotaxis; microglia; cSrc; recycling endosome
Stem cell factor (SCF) and erythropoietin are strictly required for preventing apoptosis and stimulating proliferation, allowing the differentiation of erythroid precursors from colony-forming unit-E to the polychromatophilic stage. In contrast, terminal maturation to generate reticulocytes occurs independently of cytokine signaling by a mechanism not fully understood. Terminal differentiation is characterized by a sequence of morphological changes including a progressive decrease in cell size, chromatin condensation in the nucleus and disappearance of organelles, which requires transient caspase activation. These events are followed by nucleus extrusion as a consequence of plasma membrane and cytoskeleton reorganization. Here, we show that in early step, SCF stimulates the Rho/ROCK pathway until the basophilic stage. Thereafter, ROCK-1 is activated independently of Rho signaling by caspase-3-mediated cleavage, allowing terminal maturation at least in part through phosphorylation of the light chain of myosin II. Therefore, in this differentiation system, final maturation occurs independently of SCF signaling through caspase-induced ROCK-1 kinase activation.
erythropoiesis; ROCK-1; caspases
Adult-onset atopic dermatitis (AD) has recently been recognized as a distinct disease entity, but its risk factors have not yet been clearly defined. Although gestational and perinatal exposure to tobacco smoking may be associated with the development of classic AD, the association between active/passive smoking and adult-onset AD remains controversial.
To determine if exposure to smoking, including environmental tobacco smoke (ETS), is associated with the risk of adult-onset AD.
Tobacco smoking and exposure to ETS were measured in a case–control association analysis in 83 patients with physician-diagnosed adult-onset AD and 142 age- and sex-matched controls.
Multiple logistic regression analyses showed that, among the potential environmental risk factors, both current and ever smoking were significant risk factors for adult-onset AD [odds ratio (OR) 4.994 and 3.619, respectively], compared with never smoking. Also, packs per year was significantly associated with adult-onset AD (OR 1.058, 95% confidence interval 1.028–1.089), suggesting a lifelong cumulative risk in current smokers. Moreover, nonsmokers with adult-onset AD reported significantly more exposure to ETS.
Early and/or current exposure to cigarette smoking may contribute cumulatively to the development of adult-onset AD. Exposure to ETS in childhood is associated with the development of adult-onset AD. Adults should be discouraged from smoking to prevent adult-onset AD in themselves and their family members.
To evaluate whether ratings on Clinical Dementia Rating (CDR) items related to instrumental activities of daily living (IADL) are associated with cognitive or brain morphometric characteristics of participants with mild cognitive impairment (MCI) and global CDR scores of 0.5.
Baseline cognitive and morphometric data were analyzed for 283 individuals with MCI who were divided into 2 groups (impaired and intact) based on their scores on the 3 CDR categories assessing IADL. Rates of progression to Alzheimer disease (AD) over 2 years were also compared in the 2 groups.
The impaired IADL MCI group showed a more widespread pattern of gray matter loss involving frontal and parietal regions, worse episodic memory and executive functions, and a higher percentage of individuals progressing to AD than the relatively intact IADL MCI group.
The results demonstrate the importance of considering functional information captured by the CDR when evaluating individuals with MCI, even though it is not given equal weight in the assignment of the global CDR score. Worse impairment on IADL items was associated with greater involvement of brain regions beyond the mesial temporal lobe. The conventional practice of relying on the global CDR score as currently computed underutilizes valuable IADL information available in the scale, and may delay identification of an important subset of individuals with MCI who are at higher risk of clinical decline.
Cardiorenal syndrome (CRS) type 1 is characterized by a rapid worsening of cardiac function leading to acute kidney injury (AKI). An immune-mediated damage and alteration of immune response have been postulated as potential mechanisms involved in CRS type 1. In this pilot study, we examined the possible role of the immune-mediated mechanisms in the pathogenesis of this syndrome. The main objective was to analyze in vitro that plasma of CRS type 1 patients was able to trigger a response in monocytes resulting in apoptosis. The secondary aim was to evaluate TNF-α and IL-6 plasma levels of CRS type 1 patients.
Fifteen patients with acute heart failure (AHF) and CRS type 1 were enrolled and 20 healthy volunteers without AHF or AKI were recruited as control group. Plasma from these two groups was incubated with monocytes and, subsequently, cell apoptosis was evaluated. In addition, the activity of caspase-8 was assessed after 24 h incubation. Quantitative determination of TNF-α and IL-6 levels was performed.
Plasma-induced apoptosis was significantly higher in CRS type 1 patients compared with healthy controls at 72 h (78 vs. 11%) and 96 h (81 vs. 11%). At 24 h, the activity of caspase-8 was significantly higher in monocytes incubated with plasma from the CRS type 1 group. TNF-α (2.39 vs. 28.49 pg/ml) and IL-6 (4.8 vs. 16.5 pg/ml) levels were significantly elevated in the CRS type 1 group (p < 0.01).
In conclusion, there is a defective regulation of monocyte apoptosis in CRS type 1 patients, and inflammatory pathways may have a central role in the pathogenesis of CRS type 1 and may be fundamental in damage to distant organs.
Cardiorenal syndrome; Acute heart failure; Apoptosis; Acute kidney injury
Genomic DNA replication is a necessary step in the life cycles of all organisms. To initiate DNA replication, the double-stranded DNA (dsDNA) at the origin of replication must be separated or melted; this melted region is propagated and a mature replication fork is formed. To accomplish origin recognition, initial DNA melting, and the eventual formation of a replication fork, coordinated activity of initiators, helicases, and other cellular factors are required. In this review, we focus on recent advances in the structural and biochemical studies of the initiators and the replicative helicases in multiple replication systems, with emphasis on the systems in archaeal and eukaryotic cells. These studies have yielded insights into the plausible mechanisms of the early stages of DNA replication.
FTO harbours the strongest known obesity-susceptibility locus in Europeans. While there is growing evidence for a role for FTO in obesity risk in Asians, its association with type 2 diabetes, independently of BMI, remains inconsistent. To test whether there is an association of the FTO locus with obesity and type 2 diabetes, we conducted a meta-analysis of 32 populations including 96,551 East and South Asians.
All studies published on the association between FTO-rs9939609 (or proxy [r2 > 0.98]) and BMI, obesity or type 2 diabetes in East or South Asians were invited. Each study group analysed their data according to a standardised analysis plan. Association with type 2 diabetes was also adjusted for BMI. Random-effects meta-analyses were performed to pool all effect sizes.
The FTO-rs9939609 minor allele increased risk of obesity by 1.25-fold/allele (p = 9.0 × 10−19), overweight by 1.13-fold/allele (p = 1.0 × 10−11) and type 2 diabetes by 1.15-fold/allele (p = 5.5 × 10−8). The association with type 2 diabetes was attenuated after adjustment for BMI (OR 1.10-fold/allele, p = 6.6 × 10−5). The FTO-rs9939609 minor allele increased BMI by 0.26 kg/m2 per allele (p = 2.8 × 10−17), WHR by 0.003/allele (p = 1.2 × 10−6), and body fat percentage by 0.31%/allele (p = 0.0005). Associations were similar using dominant models. While the minor allele is less common in East Asians (12–20%) than South Asians (30–33%), the effect of FTO variation on obesity-related traits and type 2 diabetes was similar in the two populations.
FTO is associated with increased risk of obesity and type 2 diabetes, with effect sizes similar in East and South Asians and similar to those observed in Europeans. Furthermore, FTO is also associated with type 2 diabetes independently of BMI.
Electronic supplementary material
The online version of this article (doi:10.1007/s00125-011-2370-7) contains peer-reviewed but unedited supplementary material, which is available to authorised users.
Asians; FTO; Meta-analysis; Obesity; Type 2 diabetes
Recent studies have shown that the opioid enkephalin (ENK), acting in part through the hypothalamic paraventricular nucleus (PVN), can stimulate consumption of a high-fat diet. The objective of the present study was to examine sub-populations of Sprague-Dawley rats naturally prone to overconsuming a high-fat diet and determine whether endogenous ENK, in different brain regions, is altered in these animals and possibly contributes to their behavioral phenotype. An animal model, involving a measure of initial high-fat diet intake during a few days of access that predicts long-term intake, was designed to classify rats at normal weight that are either high-fat consumers (HFC), which ingest 35% more calories of the high-fat than low-fat chow diet, or controls, which consume similar calories of these two diets. Immediately after their initial access to the diet, the HFC compared to control rats exhibited significantly greater expression of ENK mRNA, in the PVN, nucleus accumbens and central nucleus of the amygdala, but not the arcuate nucleus or basolateral amygdala. This site-specific increase in ENK persisted even when the HFC rats were maintained on a chow diet, suggesting that it reflects an inherent characteristic that can be expressed independently of the diet. It was also accompanied by a greater responsiveness of the HFC rats to the stimulatory effect of a PVN-injected, ENK analogue, D-ala2-met-enkephalinamide, compared to saline on consumption of the high-fat diet. Thus, normal-weight rats predicted to overconsume a fat-rich diet exhibit disturbances in endogenous ENK expression and functioning that may contribute to their long-term, behavioral phenotype.
enkephalin; high-fat diet; hypothalamus; paraventricular nucleus; nucleus accumbens; central nucleus of the amygdala; qRT-PCR; radiolabeled in situ hybridization; digoxigenin-labeled in situ hybridization; DALA; consummatory behavior; rat
VASP plays crucial roles in controlling F-actin-driven processes and growing evidence indicates that VASP function is modulated by phosphorylation at multiple sites. However, the complexity of mammalian system prevents the clear understanding of the role of VASP phosphorylation. In this study, we took advantage of Dictyostelium which possesses only one member of the Ena/VASP family to investigate the functional roles of VASP phosphorylation. Our results demonstrated that hyperosmotic stress and cAMP stimulation cause VASP phosphorylation. VASP phosphorylation plays a negative role for the early steps of filopodia/microspikes formation. VASP phosphorylation appears to modulate VASP localization at the membrane cortex and its interactions with WASP and WIPa. Analysis of chemotaxis of cells expressing VASP mutants showed that VASP phosphorylation is required for the establishment of cell polarity under a cAMP gradient.
VASP phosphorylation; Actin; Chemotaxis; Cell polarity
There are few prospective studies of prednisone-free immunosuppression (IS) in pediatric kidney transplant (KTx) recipients. We studied outcomes of a protocol using rapid discontinuation of prednisone (RDP, < 1 week) and thymoglobulin induction.
21 RDP recipients (mean age 14 ± 3 years) received KTx between 5/2002 and 12/2005 and were matched with controls (n=39) for age, race, and donor source. For the RDP group, IS consisted of prednisone tapered off over 6 days, thymoglobulin, mycophenolate mofetil, and cyclosporine (CsA). In controls, IS consisted of thymoglobulin, maintenance prednisone, azathioprine, and CsA.
For the RDP group, graft survival at 1 and 2 years was 90% and 86%; for controls, 92%, and 90% (p=0.86). For the RDP group, the incidence of acute rejection at 1 and 2 years was 14% and 19%; for controls, 23%, and 31% (p=0.l7). Of the 18 RDP recipients with functioning grafts, 89% remain prednisone free at follow-up. There was no significant difference between groups in recipient survival rates, incidence of hypertension, chronic allograft nephropathy, or cytomegalovirus disease.
RDP using thymoglobulin, MMF, and CsA in selected pediatric KTx recipients is associated with recipient and graft survival rates and acute rejection incidence comparable to quadruple drug therapy.
Prednisone withdrawal; pediatric kidney transplantation; rejection
A recent report on several cases of invasive aspergillosis caused by Neosartorya udagawae suggested distinctive patterns of disease progression between N. udagawae and Aspergillus fumigatus. This prompted us to characterize N. udagawae in comparison to A. fumigatus. Our findings showed that both species exist in two mating types at similar ratios and produce gliotoxin. However, the thermotolerance of the two species differs: while A. fumigatus is able to grow at 55°C but not at 10°C, N. udagawae is able to grow at 10°C but fails to grow at >42°C. Furthermore, compared to A. fumigatus, the conidia of N. udagawae require longer incubation periods to germinate at 37°C and are more susceptible to neutrophil attack as well as hydrogen peroxide; N. udagawae is also less virulent in gp91phox−/− mice. These findings suggest that growth and susceptibility to the host response might account for the reduced virulence of N. udagawae and the subtle distinction in the progression of the disease caused by the two species.
WASP family proteins are key players for connecting multiple signaling pathways to F-actin polymerization. To dissect the highly integrated signaling pathways controlling WASP activity, we identified a Rac protein that binds to the GTPase binding domain of WASP. Using two-hybrid and FRET-based functional assays, we identified RacC as a major regulator of WASP. RacC stimulates F-actin assembly in cell-free systems in a WASP-dependent manner. A FRET-based microscopy approach showed local activation of RacC at the leading edge of chemotaxing cells. Cells overexpressing RacC exhibit a significant increase in the level of F-actin polymerization upon cAMP stimulation, which can be blocked by a phosphatidylinositol (PI) 3-kinase inhibitor. Membrane translocation of PI 3-kinase and PI 3,4,5-trisphosphate reporter is absent in racC null cells. Cells overexpressing dominant negative RacC mutants and racC null cells move at a significantly slower speed and show a poor directionality during chemotaxis. Our results suggest that RacC plays an important role in PI 3-kinase activation and WASP activation for dynamic regulation of F-actin assembly during Dictyostelium chemotaxis.
MicroRNAs (miRNAs) are a family of small non-coding RNA molecules of about 20–23 nucleotides in length, which negatively regulate protein-coding genes at post-transcriptional level. Using a stem-loop real-time-PCR method, we quantified the expression levels of 270 human miRNAs in 13 nasopharyngeal carcinoma (NPC) samples and 9 adjacent normal tissues, and identified 35 miRNAs whose expression levels were significantly altered in NPC samples. Several known oncogenic miRNAs, including miR-17-92 cluster and miR-155, are among the miRNAs upregulated in NPC. Tumour suppressive miRNAs, including miR-34 family, miR-143, and miR-145, are significantly downregulated in NPC. To explore the roles of these dysregulated miRNAs in the pathogenesis of NPC, a computational analysis was performed to predict the pathways collectively targeted by the 22 significantly downregulated miRNAs. Several biological pathways that are well characterised in cancer are significantly targeted by the downregulated miRNAs. These pathways include TGF-Wnt pathways, G1-S cell cycle progression, VEGF signalling pathway, apoptosis and survival pathways, and IP3 signalling pathways. Expression levels of several predicted target genes in G1-S progression and VEGF signalling pathways were elevated in NPC tissues and showed inverse correlation with the down-modulated miRNAs. These results indicate that these downregulated miRNAs coordinately regulate several oncogenic pathways in NPC.
microRNA; target; pathway; nasopharyngeal carcinoma