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1.
Sci Total Environ ; 740: 140385, 2020 Oct 20.
Article in English | MEDLINE | ID: mdl-32624177

ABSTRACT

Integrating connectivity theory within watershed modelling is one solution to overcome spatial and temporal shortcomings of sediment transport prediction, and Part I and II of these companion papers advance this overall goal. In Part I of these companion papers, we present the theoretical development of probability of connectivity formula considering connectivity's magnitude, extent, timing and continuity that can be applied to watershed modelling. Model inputs include a high resolution digital elevation model, hydrologic watershed variability, and field connectivity assessments. We use the model to investigate the dependence of the probability of connected timing and spatial connectivity on sediment transport predictors. Results show the spatial patterns of connectivity depend on both structural and functional characteristics of the catchment, such as hillslope gradient, upstream contributing area, soil texture, and stream network configuration (structural) and soil moisture content and runoff generation (functional). Spatial connectivity changes from catchment-to-catchment as a function of soil type and drainage area; and it varies from event-to-event as a function of runoff depth and soil moisture conditions. The most sensitive connected pathways provide the stencil for the probability of connectivity, and pathways connected from smaller hydrologic events are consistently reconnected and built upon during larger hydrologic events. Surprisingly, we find the probability of connected timing only depends on structural characteristics of catchments, which are considered static over the timescales analyzed herein. The timing of connectivity does not statistically depend on functional characteristics, which relaxes the parameterization across events of different magnitudes. This result occurs because the pathway stencil accumulates sediment from adjacent soils as flow intensity increases, but this does not statistically shift the frequency distribution.

2.
Sci Total Environ ; 740: 140386, 2020 Oct 20.
Article in English | MEDLINE | ID: mdl-32624176

ABSTRACT

Integrating connectivity theory within watershed modelling is one solution to overcome spatial and temporal shortcomings of sediment transport prediction, and Part I and II of these companion papers advance this overall goal. In Part II of these companion papers, we investigate sediment flux via connectivity formula discretized over many catchments and then integrated via sediment routing; and we advance model evaluation technology by using hysteresis of sensor data. Model evaluation with hysteresis indices provides nearly a 100% increase in model statistics. Hysteresis loop evaluation shows a shift from near linear behavior at low to moderate events and then clock-wise loops for larger events indicating the importance of proximal sediment sources. Catchment-scale sediment flux varies as function of the probability of timing and extent of connectivity of an individual catchment. Watershed-scale sediment flux shows self-similarity for the main stem of the river channel as the 181 catchments are integrated moving down gradient. Sediment flux varies from event-to-event as a function of the most sensitive connected pathways, including ephemeral gullies and roadside ditches in this basin. These sensitive pathways contribute disproportionately large amounts to overall sediment yield regardless of the total rainfall depth. Prediction requires the connectivity formula, erosion formula and sediment routing formula; and the probability of connectivity alone was a poor predictor for sediment transport. The result highlights the importance of coupling connectivity simulations with sediment transport formula, and our method provides one such approach.

4.
Clin Rev Allergy Immunol ; 51(1): 16-26, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26578261

ABSTRACT

Osteoclasts are multinucleated cells derived from mononuclear phagocyte precursors (monocytes, macrophages); in the canonical pathway of osteoclastogenesis, these cells fuse and differentiate to form specialised bone-resorbing osteoclasts in the presence of receptor activator for nuclear factor kappa B ligand (RANKL). Non-canonical pathways of osteoclastogenesis have been described in which several cytokines and growth factors are able to substitute for RANKL. These humoral factors can generally be divided into those which, like RANKL, are tumour necrosis family (TNF) superfamily members and those which are not; the former include TNFα lymphotoxin exhibiting inducible expression and competing with herpes simplex virus glycoprotein D for herpesvirus entry mediator, a receptor expressed by T lymphocytes (LIGHT), a proliferation inducing ligand (APRIL) and B cell activating factor (BAFF); the latter include transforming growth factor beta (TGF-ß), interleukin-6 (IL-6), IL-8, IL-11, nerve growth factor (NGF), insulin-like growth factor-I (IGF-I) and IGF-II. This review summarises the evidence for these RANKL substitutes in inducing osteoclast differentiation from tissue-derived and circulating mononuclear phagocytes. It also assesses the role these factors are likely to play in promoting the pathological bone resorption seen in many inflammatory and neoplastic lesions of bone and joint including rheumatoid arthritis, aseptic implant loosening and primary and secondary tumours of bone.


Subject(s)
Bone Resorption/metabolism , Musculoskeletal Diseases/metabolism , Osteoclasts/cytology , Osteoclasts/metabolism , RANK Ligand/metabolism , Signal Transduction , Bone Resorption/pathology , Cytokines/metabolism , Humans , Multigene Family , Musculoskeletal Diseases/genetics , Musculoskeletal Diseases/pathology , Protein Binding , Receptor Activator of Nuclear Factor-kappa B/metabolism , Tumor Necrosis Factor Ligand Superfamily Member 14/metabolism , Tumor Necrosis Factors/genetics , Tumor Necrosis Factors/metabolism
5.
Aliment Pharmacol Ther ; 39(12): 1408-17, 2014 Jun.
Article in English | MEDLINE | ID: mdl-24779703

ABSTRACT

BACKGROUND: Chronic ulcerative colitis (CUC) and colonic Crohn's disease (CD) increase colorectal neoplasia (CRN) risk. While sessile serrated polyp (SSP) is a known cancer precursor, serrated epithelial changes (SEC) are of uncertain prevalence and neoplastic risk. AIM: To assess the serrated lesion detection rates in CUC and CD and documented incidence of subsequent CRN in a retrospective, single-centre cohort study. METHODS: Patients were identified by a central diagnostic index and pathology review confirmed SEC, SSP, CUC and CD diagnoses from 2006-12. Matched controls were identified from among all CUC and CD patients having colonoscopy during the second half of the time period. All were followed for incident CRN, estimated by the Kaplan-Meier method. RESULTS: Between 2006 and 2012, 79 SEC and 10 SSP cases were identified. Detection rates were estimated to be 10/1000 and 2/1000 patients, for SEC and SSP respectively, among 4208 unique CUC or CD patients having colonoscopy from 2010-12. With only 10 cases, SSP patients were not further analysed. Cumulative incidence of subsequent CRN at 1 and 3 years was 12% (95% CI, 0-30%) and 30% (3-57%), respectively, in SEC patients compared to 4% (0-12%) and 9% (0-23%), respectively, in CUC or CD controls (P = 0.047, log-rank). However, this statistical difference was not significant after patients were stratified for history of prior or synchronous dysplasia (P = 0.09). CONCLUSIONS: Serrated epithelial changes and sessile serrated polyps are uncommonly detected by colonoscopy in chronic ulcerative colitis and Crohn's disease patients. Histology with changes of serrated epithelium may be associated with risk of subsequent colorectal neoplasia, however further studies are needed to explore this relationship.


Subject(s)
Colitis, Ulcerative/pathology , Colon/pathology , Crohn Disease/pathology , Intestinal Mucosa/pathology , Adult , Aged , Colitis, Ulcerative/complications , Colitis, Ulcerative/epidemiology , Colonoscopy/methods , Crohn Disease/complications , Crohn Disease/epidemiology , Female , Humans , Incidence , Male , Middle Aged , Neoplasms/epidemiology , Neoplasms/etiology , Retrospective Studies
6.
Haemophilia ; 20(3): e211-4, 2014 May.
Article in English | MEDLINE | ID: mdl-24581275

ABSTRACT

Exon 28 polymorphism p.D1472H is associated with significantly lower von Willebrand Ristocetin cofactor activity (VWF:RCoF) to von Willebrand antigen (VWF:Ag) ratio compared to normal, but has been reported as not conferring haemorrhagic risk. The impact of this polymorphism while assessing symptomatic patients for von Willebrand disease (VWD) has not been previously analysed. We retrospectively reviewed charts of children with clinically significant bleeding and abnormal VW panel who underwent VW exon 28 analysis. Twenty-three of 63 patients studied had p.D1472H. Of these 23 patients, 6 with borderline low VWF:RCo were given provisional diagnosis of VWD type 1 by treating physicians, which could be alternatively explained as due to the effect of p.D1472H. None of the patients with low VWF:RCo, decreased VWF:RCo/VWF:Ag ratio and p.D1472H had VWD type 2M mutations identified. This study illustrates the challenge in diagnosing VWD using ristocetin-based VW assay in symptomatic patients with p.D1472H.


Subject(s)
Exons , Hemorrhage/genetics , von Willebrand Diseases/diagnosis , von Willebrand Diseases/genetics , von Willebrand Factor/genetics , Adolescent , Child , Child, Preschool , Humans , Infant , Phenotype , Polymorphism, Genetic , Retrospective Studies
7.
Haemophilia ; 20(2): 249-54, 2014 Mar.
Article in English | MEDLINE | ID: mdl-24251971

ABSTRACT

Platelet function defects (PFD) are reported to occur frequently in adult women with heavy menstrual bleeding (HMB). Few studies on adolescent HMB report varying incidence rates (2-44%) for PFD. We reviewed our institutional experience in detecting and managing PFD in adolescent HMB. Postmenarchial girls and adolescents with HMB seen at our institution undergo a comprehensive bleeding disorder work-up by paediatric haematology and paediatric gynaecology providers. Whole blood platelet aggregometry (WBPA) is performed as a second tier test after excluding thrombocytopaenia, coagulation factor deficiencies and Von Willebrand disease (VWD). We retrospectively reviewed the medical records of adolescents with HMB seen between June 2009 and November 2010, as approved by the Institutional Review Board. Patient demographics, clinical features, laboratory results, therapy details and patient outcome information were analysed. Overall, 114 postmenarchial girls and adolescents with HMB were evaluated; 68 patients (59%) had WBPA study performed. Nineteen patients (28%) had at least one aggregation or secretion defect; 12 (18%) had two or more such defects. Treatment included hormonal therapy (13/19; 68%), antifibrinolytic agents (8/19; 42%) and intra-nasal DDAVP (3/19; 16%). Thirteen patients (81%) had improved outcome (median follow-up--15.6 months; range of 1-66 months). In this study, PFD were identified in nearly one-third of girls with HMB, with the majority of these having two or more defects as identified by WBPA. Further prospective studies are needed to better define the prevalence and address appropriate management of HMB and other bleeding complications of PFD in adolescents.


Subject(s)
Blood Platelets/metabolism , Menorrhagia/etiology , Adolescent , Adult , Antifibrinolytic Agents/therapeutic use , Blood Platelets/drug effects , Child , Deamino Arginine Vasopressin/therapeutic use , Female , Humans , Menorrhagia/diagnosis , Menorrhagia/drug therapy , Platelet Aggregation/drug effects , Platelet Function Tests , Retrospective Studies , Young Adult
8.
Aliment Pharmacol Ther ; 37(5): 546-54, 2013 Mar.
Article in English | MEDLINE | ID: mdl-23347191

ABSTRACT

BACKGROUND: Current approaches to the detection of colorectal neoplasia associated with inflammatory bowel disease (IBD-CRN) are suboptimal. AIM: To test the feasibility of using stool assay of exfoliated DNA markers to detect IBD-CRN. METHODS: This investigation comprised tissue and stool studies. In the tissue study, gene sequencing and methylation assays were performed on candidate genes using tissue DNA from 25 IBD-CRNs and from 25 IBD mucosae without CRN. Mutations on p53, APC, KRAS, BRAF or PIK3CA genes were insufficiently informative, but several aberrantly methylated genes were highly discriminant. In the stool study, we evaluated candidate methylated genes (vimentin, EYA4, BMP3, NDRG4) in a prospective blinded study on buffered stools from 19 cases with known IBD-CRN and 35 age- and sex-matched IBD controls without CRN. From stool-extracted DNA, target genes were assayed using quantitative allele-specific real-time target and signal amplification method. RESULTS: IBD-CRN cases included 17 with ulcerative colitis (UC) and two with Crohn's disease (CD); nine had cancer and 10 had dysplasia. Controls included 25 with UC and 10 with CD. Individually, BMP3, vimentin, EYA4 and NDRG4 markers showed high discrimination in stools with respective areas under the ROC curve of 0.91, 0.91, 0.85 and 0.84 for total IBD-CRN and of 0.97, 0.97, 0.95 and 0.85 for cancer. At 89% specificity, the combination of BMP3 and mNDRG4 detected 9/9 (100%) of CRC and 80% of dysplasia, 4/4 (100%) of high grade and 4/6 (67%) of low grade. CONCLUSION: These findings demonstrate the feasibility of stool DNA testing for non-invasive detection of colorectal neoplasia associated with inflammatory bowel disease.


Subject(s)
Biomarkers, Tumor/genetics , Colorectal Neoplasms/diagnosis , DNA, Neoplasm/analysis , Feces/chemistry , Inflammatory Bowel Diseases/diagnosis , Adult , Aged , Colorectal Neoplasms/genetics , Female , Genetic Markers/genetics , Humans , Inflammatory Bowel Diseases/genetics , Male , Middle Aged , Predictive Value of Tests
9.
Caries Res ; 47(1): 27-33, 2013.
Article in English | MEDLINE | ID: mdl-23051625

ABSTRACT

Early detection of dental caries is vital if improved patient outcomes are to be achieved by reversal of the demineralization process. Current techniques used by dentists for identifying carious lesions are effective in identifying more advanced lesions, but do not have sufficient sensitivity and specificity to detect them at the earliest stages. This study focused on characterizing the growth of incipient carious lesions in vitro using micro-Raman spectroscopy. The incipient carious lesions were grown on the buccal faces of human molars by controlled exposure to lactic acid. Lesions were cross-sectioned to expose the subsurface body of the lesion and then examined using micro-Raman spectroscopy. The intensity of the phosphate peaks in the Raman spectra was found to differ significantly between healthy enamel and the demineralized region of the lesions. The sensitivity of the phosphate peaks to the degree of demineralization was observed by taking a series of spectra over the cross section of the lesions. This revealed that the body of the lesion is highly demineralized, but in a narrow surface region (up to 10 µm) there is little demineralization. All the phosphate peaks were found to be sensitive to the degree of demineralization; however, changes in the intensity of the pronounced phosphate peak at 961 cm(-1) offer the most promise for identifying lesions. The results indicate that micro-Raman spectroscopy has both the sensitivity and selectivity to identify incipient carious lesions, but the presence of a surface layer with a relatively high mineral content could complicate the analysis.


Subject(s)
Dental Caries/diagnosis , Dental Enamel/pathology , Spectrum Analysis, Raman/methods , Carbonates/analysis , Cariogenic Agents/adverse effects , Dental Caries/metabolism , Dental Enamel/chemistry , Dentin/chemistry , Dentin/pathology , Humans , Hydrogen-Ion Concentration , Lactic Acid/adverse effects , Minerals/analysis , Phosphates/analysis , Sensitivity and Specificity , Tooth Demineralization/metabolism
10.
Br J Cancer ; 108(2): 245-9, 2013 Feb 05.
Article in English | MEDLINE | ID: mdl-23169279

ABSTRACT

Functional genomic screening has emerged as a powerful approach for understanding complex biological phenomena. Of the available tools, genome-wide RNA interference (RNAi) technology is unquestionably the most incisive, as it directly probes gene function. Recent applications of RNAi screening have been impressive. Notable amongst these are its use in elucidated mechanism(s) for signal transduction, various aspects of cell biology, tumourigenesis and metastasis, resistance to cancer therapeutics, and the host's response to a pathogen. Herein we discuss how recent RNAi screening efforts have helped turn our attention to the targetability of non-oncogene support pathways for cancer treatment, with a particular focus on a recent study that identified a non-oncogene addiction to the ER stress response as a synergist target for oncolytic virus therapy (OVT). Moreover, we give our thoughts on the future of RNAi screening as a tool to enhance OVT and describe recent technical improvements that are poised to make genome-scale RNAi experiments more sensitive, less noisy, more applicable in vivo, and more easily validated in clinically relevant animal models.


Subject(s)
Genetic Testing , High-Throughput Screening Assays , Neoplasms/therapy , Oncolytic Virotherapy , RNA Interference , Genomics , Humans , Oncolytic Viruses , RNA, Small Interfering/genetics
11.
Persoonia ; 29: 146-201, 2012 Dec.
Article in English | MEDLINE | ID: mdl-23606771

ABSTRACT

Novel species of microfungi described in the present study include the following from Australia: Catenulostroma corymbiae from Corymbia, Devriesia stirlingiae from Stirlingia, Penidiella carpentariae from Carpentaria, Phaeococcomyces eucalypti from Eucalyptus, Phialophora livistonae from Livistona, Phyllosticta aristolochiicola from Aristolochia, Clitopilus austroprunulus on sclerophyll forest litter of Eucalyptus regnans and Toxicocladosporium posoqueriae from Posoqueria. Several species are also described from South Africa, namely: Ceramothyrium podocarpi from Podocarpus, Cercospora chrysanthemoides from Chrysanthemoides, Devriesia shakazului from Aloe, Penidiella drakensbergensis from Protea, Strelitziana cliviae from Clivia and Zasmidium syzygii from Syzygium. Other species include Bipolaris microstegii from Microstegium and Synchaetomella acerina from Acer (USA), Brunneiapiospora austropalmicola from Rhopalostylis (New Zealand), Calonectria pentaseptata from Eucalyptus and Macadamia (Vietnam), Ceramothyrium melastoma from Melastoma (Indonesia), Collembolispora aristata from stream foam (Czech Republic), Devriesia imbrexigena from glazed decorative tiles (Portugal), Microcyclospora rhoicola from Rhus (Canada), Seiridium phylicae from Phylica (Tristan de Cunha, Inaccessible Island), Passalora lobeliae-fistulosis from Lobelia (Brazil) and Zymoseptoria verkleyi from Poa (The Netherlands). Valsalnicola represents a new ascomycete genus from Alnus (Austria) and Parapenidiella a new hyphomycete genus from Eucalyptus (Australia). Morphological and culture characteristics along with ITS DNA barcodes are also provided.

12.
Cytokine Growth Factor Rev ; 21(2-3): 161-7, 2010.
Article in English | MEDLINE | ID: mdl-20207578

ABSTRACT

Replicating virus-based therapeutics for cancer, or oncolytic virus therapy (OVT), is rapidly emerging as a promising treatment modality for a wide range of cancers. In pre-clinical studies, oncolytic viruses have produced remarkable results in a variety of experimental animal models, and several viruses have entered phase I/II clinical trials. However, OVT is not effective against all tumours, with major treatment bottlenecks being the inability to infect, replicate within, or kill certain cancer cells. Unfortunately, the underlying molecular mechanisms governing these limitations are largely unknown. Recently, RNAi technology has been adapted for systematic interrogation of entire eukaryotic genomes. Since then, several groups have conducted genome-wide RNAi screens to study host/virus interactions. Herein we briefly summarize RNAi screening and its recent application to virology, and propose its use in overcoming key barriers to successful OVT.


Subject(s)
Oncolytic Virotherapy/methods , Oncolytic Viruses , RNA Interference , Animals , Host-Pathogen Interactions , Humans , Virus Replication
13.
J Biomech Eng ; 130(6): 061001, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19045530

ABSTRACT

Tissue engineering often involves seeding cells into porous scaffolds and subjecting the scaffold to mechanical stimulation. Current experimental techniques have provided a plethora of data regarding cell responses within scaffolds, but the quantitative understanding of the load transfer process within a cell-seeded scaffold is still relatively unknown. The objective of this work was to develop a finite element representation of the transient and heterogeneous nature of a cell-seeded collagen-GAG-scaffold. By undertaking experimental investigation, characteristics such as scaffold architecture and shrinkage, cellular attachment patterns, and cellular dimensions were used to create a finite element model of a cell-seeded porous scaffold. The results demonstrate that a very wide range of microscopic strains act at the cellular level when a sample value of macroscopic (apparent) strain is applied to the collagen-GAG-scaffold. An external uniaxial strain of 10% generated a cellular strain as high as 49%, although the majority experienced less than approximately 5% strain. The finding that the strain on some cells could be higher than the macroscopic strain was unexpected and proves contrary to previous in vitro investigations. These findings indicate a complex system of biophysical stimuli created within the scaffolds and the difficulty of inducing the desired cellular responses from artificial environments. Future in vitro studies could also corroborate the results from this computational prediction to further explore mechanoregulatory mechanisms in tissue engineering.


Subject(s)
Extracellular Matrix/chemistry , Mechanotransduction, Cellular/physiology , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/physiology , Models, Biological , Tissue Engineering/methods , Animals , Cell Culture Techniques/methods , Cells, Cultured , Computer Simulation , Elastic Modulus/physiology , Finite Element Analysis , Male , Physical Stimulation/methods , Porosity , Rats , Rats, Wistar , Shear Strength/physiology , Stem Cells , Stress, Mechanical
14.
Oncogene ; 27(48): 6252-75, 2008 Oct 20.
Article in English | MEDLINE | ID: mdl-18931692

ABSTRACT

DNA damage, chromosomal abnormalities, oncogene activation, viral infection, substrate detachment and hypoxia can all trigger apoptosis in normal cells. However, cancer cells acquire mutations that allow them to survive these threats that are part and parcel of the transformation process or that may affect the growth and dissemination of the tumor. Eventually, cancer cells accumulate further mutations that make them resistant to apoptosis mediated by standard cytotoxic chemotherapy or radiotherapy. The inhibitor of apoptosis (IAP) family members, defined by the presence of a baculovirus IAP repeat (BIR) protein domain, are key regulators of cytokinesis, apoptosis and signal transduction. Specific IAPs regulate either cell division, caspase activity or survival pathways mediated through binding to their BIR domains, and/or through their ubiquitin-ligase RING domain activity. These protein-protein interactions and post-translational modifications are the subject of intense investigations that shed light on how these proteins contribute to oncogenesis and resistance to therapy. In the past several years, we have seen multiple approaches of IAP antagonism enter the clinic, and the rewards of such strategies are about to reap benefit. Significantly, small molecule pan-IAP antagonists that mimic an endogenous inhibitor of the IAPs, called Smac, have demonstrated an unexpected ability to sensitize cancer cells to tumor necrosis factor-alpha and to promote autocrine or paracrine production of this cytokine by the tumor cell and possibly, other cells too. This review will focus on these and other developmental therapeutics that target the IAPs in cancer.


Subject(s)
Inhibitor of Apoptosis Proteins/antagonists & inhibitors , Neoplasms/therapy , Animals , Genetic Therapy , Humans , Inhibitor of Apoptosis Proteins/genetics , Mice , Ubiquitination
15.
Proc Natl Acad Sci U S A ; 105(33): 11778-83, 2008 Aug 19.
Article in English | MEDLINE | ID: mdl-18697935

ABSTRACT

The cellular inhibitor of apoptosis 1 and 2 (cIAP1 and cIAP2) proteins have been implicated in the activation of NF-kappaB by TNFalpha; however, genetic deletion of either cIAP1 or 2 did not support a physiologically relevant role, perhaps because of functional redundancy. To address this, we used combined genetic and siRNA knockdown approaches and report that cIAP1 and 2 are indeed critical, yet redundant, regulators of NF-kappaB activation upon TNFalpha treatment. Whereas NF-kappaB was properly activated by TNFalpha in cultured and primary cells deficient in either cIAP1 or 2, removal of both cIAPs severely blunted its activation. After treatment with TNFalpha, cIAP1 and 2 were rapidly recruited to the TNF receptor 1, along with the adapter protein TNF receptor associated factor 2. Importantly, either cIAP1 or 2 was required for proper TNF receptor 1 signalosome function. In their combined absence, polyubiquitination of receptor interacting protein 1, an upstream event necessary for NF-kappaB signaling, was attenuated. As a result, phosphorylation of the inhibitor of kappaB kinase beta was diminished, and signal transduction was severely blunted. Consequently, cells missing both cIAP1 and 2 were sensitized to TNFalpha-mediated apoptosis. Collectively, these data demonstrate that either cIAP1 or 2 is required for proper Rip1 polyubiquitination and NF-kappaB activation upon TNFalpha treatment.


Subject(s)
Inhibitor of Apoptosis Proteins/metabolism , NF-kappa B/metabolism , Tumor Necrosis Factor-alpha/pharmacology , Animals , Apoptosis/drug effects , Cells, Cultured , GTPase-Activating Proteins/metabolism , Inhibitor of Apoptosis Proteins/deficiency , Inhibitor of Apoptosis Proteins/genetics , Mice , Mice, Knockout , Myoblasts/drug effects , Myoblasts/metabolism , Signal Transduction/drug effects , TNF Receptor-Associated Death Domain Protein/metabolism , Ubiquitination
16.
Am J Physiol Regul Integr Comp Physiol ; 294(6): R1901-10, 2008 Jun.
Article in English | MEDLINE | ID: mdl-18321953

ABSTRACT

We used cDNA microarrays to screen for differentially expressed genes during recovery from exercise-induced muscle damage in humans. Male subjects (n = 4) performed 300 maximal eccentric contractions, and skeletal muscle biopsy samples were analyzed at 3 h and 48 h after exercise. In total, 113 genes increased 3 h postexercise, and 34 decreased. At 48 h postexercise, 59 genes increased and 29 decreased. On the basis of these data, we chose 19 gene changes and conducted secondary analyses using real-time RT-PCR from muscle biopsy samples taken from 11 additional subjects who performed an identical bout of exercise. Real-time RT-PCR analyses confirmed that exercise-induced muscle damage led to a rapid (3 h) increase in sterol response element binding protein 2 (SREBP-2), followed by a delayed (48 h) increase in the SREBP-2 gene targets Acyl CoA:cholesterol acyltransferase (ACAT)-2 and insulin-induced gene 1 (insig-1). The expression of the IL-1 receptor, a known regulator of SREBP-2, was also elevated after exercise. Taken together, these expression changes suggest a transcriptional program for increasing cholesterol and lipid synthesis and/or modification. Additionally, damaging exercise induced the expression of protein kinase H11, capping protein Z alpha (capZalpha), and modulatory calcineurin-interacting protein 1 (MCIP1), as well as cardiac ankryin repeat protein 1 (CARP1), DNAJB2, c-myc, and junD, each of which are likely involved in skeletal muscle growth, remodeling, and stress management. In summary, using DNA microarrays and RT-PCR, we have identified novel genes that respond to skeletal muscle damage, which, given the known biological functions, are likely involved in recovery from and/or adaptation to damaging exercise.


Subject(s)
Exercise/physiology , Gene Expression Profiling , Muscle, Skeletal/metabolism , Adult , Apoptosis Regulatory Proteins , Biopsy , CapZ Actin Capping Protein/metabolism , Carrier Proteins/metabolism , Cell Cycle Proteins , DNA-Binding Proteins , HSP40 Heat-Shock Proteins/metabolism , Humans , Inflammation/metabolism , Inflammation/physiopathology , Intracellular Signaling Peptides and Proteins/metabolism , Male , Molecular Chaperones/metabolism , Muscle Proteins/metabolism , Muscle, Skeletal/pathology , Oligonucleotide Array Sequence Analysis , Proto-Oncogene Proteins c-jun/metabolism , Proto-Oncogene Proteins c-myc/metabolism , Receptors, Interleukin-1/metabolism , Sterol Regulatory Element Binding Protein 2/metabolism
17.
Pediatr Transplant ; 12(3): 368-71, 2008 May.
Article in English | MEDLINE | ID: mdl-18346036

ABSTRACT

The prothrombin G20210A mutation has been associated with an increased risk of graft failure in renal transplant recipients. Little is known about the potential effect of this mutation on lung transplant recipients. We report the case of bilateral lung transplantation in a patient with cystic fibrosis who was heterozygous for the G20210A mutation of the prothrombin gene.


Subject(s)
Cystic Fibrosis/genetics , Cystic Fibrosis/therapy , Lung Transplantation/methods , Mutation , Prothrombin/genetics , Thrombophilia/complications , Adult , Cystic Fibrosis/complications , Cystic Fibrosis/surgery , Enoxaparin/therapeutic use , Fatal Outcome , Female , Heparin/therapeutic use , Heterozygote , Humans , Hypertension, Pulmonary/etiology , Mental Disorders/complications , Risk , Thrombophilia/genetics
18.
J Thromb Haemost ; 6(4): 589-94, 2008 Apr.
Article in English | MEDLINE | ID: mdl-18194413

ABSTRACT

BACKGROUND: Deep vein thrombosis (DVT) is a complication of treatment of acute lymphoblastic leukemia (ALL) in children but little is known about the long-term outcomes of these DVT. OBJECTIVE: To determine the incidence of post-thrombotic syndrome (PTS) in (i) children with ALL diagnosed with asymptomatic DVT using radiographic testing and (ii) an unselected group of ALL survivors. METHODS: Cross-sectional study in two populations. Group I comprised children in the Prophylactic Antithrombin Replacement in Kids with ALL treated with L-Asparaginase (PARKAA) study diagnosed with DVT by radiographic tests. Group II consisted of non-selected childhood ALL survivors <21 years. PTS was assessed using a standardized scoring sheet. RESULTS: Group I: 13 PARKAA patients (median age 12 years) were assessed, and 7 had PTS (54%; 95% CI, 25-81). All patients had collaterals, three also had increased arm circumference. Group II: 41 patients (median age 13 years) with a history of ALL were enrolled, and 10 had PTS (24%; 95% CI, 11-38). All patients had collaterals; five also had increased arm circumference. CONCLUSION: There is a high incidence of PTS in survivors of childhood ALL with radiographically diagnosed asymptomatic DVT. A significant proportion of ALL survivors develop PTS, indicating previously undiagnosed DVT.


Subject(s)
Postthrombotic Syndrome/epidemiology , Precursor Cell Lymphoblastic Leukemia-Lymphoma/drug therapy , Venous Thrombosis/complications , Adolescent , Adult , Antineoplastic Combined Chemotherapy Protocols/adverse effects , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Antithrombin III Deficiency/chemically induced , Arm/blood supply , Arm/pathology , Asparaginase/administration & dosage , Asparaginase/adverse effects , Catheterization, Central Venous/adverse effects , Child , Child, Preschool , Clinical Trials, Phase II as Topic/statistics & numerical data , Collateral Circulation , Cross-Sectional Studies , Female , Follow-Up Studies , Humans , Incidence , Male , Multicenter Studies as Topic/statistics & numerical data , Precursor Cell Lymphoblastic Leukemia-Lymphoma/blood , Prevalence , Randomized Controlled Trials as Topic/statistics & numerical data , Survivors , Thrombophilia/chemically induced , Venous Thrombosis/epidemiology
19.
J Long Term Eff Med Implants ; 18(4): 269-88, 2008.
Article in English | MEDLINE | ID: mdl-20370640

ABSTRACT

The objective of this study was to investigate the effects of intervertebral disk degeneration on the flexibility of the thoracolumbar spine in flexion and extension, both experimentally and computationally. A seven-level biomechanically tested human cadaveric spine (T11-L5) and a 3D finite element model of the same thoracolumbar spine were used for this purpose. The anatomically accurate computer model was generated from detailed computed tomography images and included the vertebral shell, the trabecular centrum, cartilage endplates, intervertebral disks, seven spinal ligament groups, and the facet joints. The cadaveric spinal segment and the specimen-specific finite element model were subjected to various compressive loads ranging from 75 to 975 N using the follower load principle and an oscillating bending moment of +/-5 Nm applied in the sagittal plane. The biomechanical behavior of the finite element model of the spine was validated with the experimental mechanical test data for the corresponding physical thoracolumbar spine specimen. In addition, the effect of intervertebral disk material property variation within the thoracolumbar spinal column on the spinal flexibility was extensively studied. The results of this study provided significant insight into how mechanical properties of the intervertebral disk influence spinal flexibility along the thoracolumbar spinal column. It was found that in order to get comparable results between experimental and computed data, the material properties of the intervertebral disks had to vary along the spinal column. However, these effects are diminished with increasing axial compressive load. Because of the trend between disk properties and spinal level, we further concluded that there might be a mechanism at play that links endplate size, body weight fraction, and segmental flexibility. More studies are needed to further investigate that relationship.


Subject(s)
Intervertebral Disc Degeneration/physiopathology , Lumbar Vertebrae , Range of Motion, Articular , Thoracic Vertebrae , Biomechanical Phenomena , Cadaver , Elasticity , Finite Element Analysis , Humans , Models, Biological , Reproducibility of Results , Weight-Bearing
20.
Acta Bioeng Biomech ; 9(1): 35-46, 2007.
Article in English | MEDLINE | ID: mdl-17933103

ABSTRACT

The goal of this study was to generate a realistic 3D FE model of the seven level thoracolumbar spine. This research focused on the development of a robust and efficient procedure for generating anatomical 3D FE models, directly from a series of medical images, i.e., CT data. A complex model of the spine was created by combining two different modelling approaches, namely the CAD and STL-CAD methods. In addition, the entire meshing procedure for the vertebrae was significantly speeded up by combining 3D tetrahedral elements with brick elements, relative to conventional mapped mesh generation procedures. The resulting model generation method allowed for flexibility in element choice and in element type combinations. The model was subjected to various compressive loads to asses the overall behaviour of the spine. This case study was performed to illustrate the usefulness of the FE model. In the authors' opinion, the model presented is an important tool in computational spine research as it can provide general information on spinal behaviour under various loading conditions whether healthy, diseased or damaged.


Subject(s)
Computer Simulation , Finite Element Analysis , Lumbar Vertebrae/physiology , Models, Anatomic , Thoracic Vertebrae/physiology , Biomechanical Phenomena , Humans
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