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1.
N Engl J Med ; 388(23): 2121-2131, 2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37285526

RESUMO

BACKGROUND: Data showing the efficacy and safety of the transplantation of hearts obtained from donors after circulatory death as compared with hearts obtained from donors after brain death are limited. METHODS: We conducted a randomized, noninferiority trial in which adult candidates for heart transplantation were assigned in a 3:1 ratio to receive a heart after the circulatory death of the donor or a heart from a donor after brain death if that heart was available first (circulatory-death group) or to receive only a heart that had been preserved with the use of traditional cold storage after the brain death of the donor (brain-death group). The primary end point was the risk-adjusted survival at 6 months in the as-treated circulatory-death group as compared with the brain-death group. The primary safety end point was serious adverse events associated with the heart graft at 30 days after transplantation. RESULTS: A total of 180 patients underwent transplantation; 90 (assigned to the circulatory-death group) received a heart donated after circulatory death and 90 (regardless of group assignment) received a heart donated after brain death. A total of 166 transplant recipients were included in the as-treated primary analysis (80 who received a heart from a circulatory-death donor and 86 who received a heart from a brain-death donor). The risk-adjusted 6-month survival in the as-treated population was 94% (95% confidence interval [CI], 88 to 99) among recipients of a heart from a circulatory-death donor, as compared with 90% (95% CI, 84 to 97) among recipients of a heart from a brain-death donor (least-squares mean difference, -3 percentage points; 90% CI, -10 to 3; P<0.001 for noninferiority [margin, 20 percentage points]). There were no substantial between-group differences in the mean per-patient number of serious adverse events associated with the heart graft at 30 days after transplantation. CONCLUSIONS: In this trial, risk-adjusted survival at 6 months after transplantation with a donor heart that had been reanimated and assessed with the use of extracorporeal nonischemic perfusion after circulatory death was not inferior to that after standard-care transplantation with a donor heart that had been preserved with the use of cold storage after brain death. (Funded by TransMedics; ClinicalTrials.gov number, NCT03831048.).


Assuntos
Morte Encefálica , Transplante de Coração , Obtenção de Tecidos e Órgãos , Adulto , Humanos , Sobrevivência de Enxerto , Preservação de Órgãos , Doadores de Tecidos , Morte , Segurança do Paciente
2.
Phys Chem Chem Phys ; 25(44): 30612-30626, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37933192

RESUMO

The direct epoxidation of propylene is one of the most important selective oxidation reactions in industry. The development of high-performance copper-based catalysts is the key to the selective oxidation technology and scientific research of propylene. The mechanism of propylene's partial oxidation catalyzed by Cu(111) under different oxygen coverage conditions was studied using density functional theory calculations and microkinetic modeling. We report here in detail two parallel reaction pathways: dehydrogenation and epoxidation. The transition states and energy distributions of the intermediates and products were calculated. The present results showed that propylene oxide (PO) selectivity was high under low oxygen coverage, and increasing the oxygen coverage would decrease the PO selectivity but increase the PO activity, and there was an inverse relationship between PO selectivity and activity. Increasing oxygen coverage would reduce the energy barrier for the C-O bond formation of C3H5O due to the weaker adsorption strength of C3H5, thus decreasing the PO formation selectivity. On the other hand, increasing oxygen coverage would reduce the energy barrier for the possible reaction steps of propylene epoxidation in general, and thus increasing the catalytic activity. It might be proposed that the active site for propylene epoxidation is the metallic copper or partially oxidized copper in terms of the change of PO formation selectivity with oxygen coverage.

3.
Appl Opt ; 61(24): 6953-6960, 2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36256309

RESUMO

To achieve an effective phase unwrapping for hue-based fringe projection profilometry, this paper proposes a hue-indexing-based absolute phase retrieval method using a discrete hue sequence. First, the hue component is extracted as the wrapped phase for 3D reconstruction by projecting a programmed hue fringe pattern. Afterward, a hue-indexing sequence with a random combination of six unique hues from the hue map is designed for hue unwrapping. By assigning a hue index of the fringe geometric center, the defocusing effect in the hue unwrapping is corrected, where the fringe order of the wrapped hue is then uniquely identified. The simulations show that the root mean square (RMS) of the residual error is 2.2185×10-4 r a d, and the effectiveness of the proposed method is further verified through experiments using a plaster statue and a compressor blade. The measurement comparison of the proposed method and the coordinate measuring machine is provided, where the RMS error of the measured deviation is 4.09×10-2 m m.

4.
J Exp Bot ; 72(13): 4888-4903, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-33940615

RESUMO

GIBBERELLIN MYB GENE (GAMYB), UNDEVELOPED TAPETUM1 (UDT1), TDR INTERACTING PROTEIN2 (TIP2/bHLH142), TAPETUM DEGENERATION RETARDATION (TDR), and ETERNAL TAPETUM 1/DELAYED TAPETUM DEGENERATION (EAT1/DTD) are important transcription factors that play a crucial role during pollen development in rice. This study demonstrates that bHLH142 acts downstream of UDT1 and GAMYB and works as a 'hub' in these two pollen pathways. We show that GAMYB modulates bHLH142 expression through specific binding to the MYB motif of the bHLH142 promoter during the early stage of pollen development, while TDR acts as a transcriptional repressor of the GAMYB modulation of bHLH142 by binding to the E-box close to the MYB motif on the promoter. Altered expression of these transcription factors highlights that a tight, precise, and coordinated regulation among them is essential for normal pollen development. Most notably, we show that the regulatory pathways of GAMYB and UDT1 rely on bHLH142 in a direct and indirect manner, respectively, and function in different tissues with distinct biological roles during pollen development. This study advances our understanding of the molecular mechanisms of rice pollen development.


Assuntos
Oryza , Flores/genética , Flores/metabolismo , Regulação da Expressão Gênica de Plantas , Oryza/genética , Oryza/metabolismo , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Pólen/genética , Pólen/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
5.
J Biol Chem ; 293(39): 15055-15069, 2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30082316

RESUMO

Antibody-mediated blockade of cluster of differentiation 47 (CD47)-thrombospondin-1 (TSP-1) interactions blocks osteoclast formation in vitro and attenuates parathyroid hormone (PTH)-induced hypercalcemia in vivo in mice. Hypercalcemia in this model reflects increased bone resorption. TSP-1 has two cell-associated binding partners, CD47 and CD36. The roles of these two molecules in mediating the effects of TSP1 in osteoclasts are unclear. Osteoclast formation was attenuated but not absent when preosteoclasts isolated from CD47-/- mice were cocultured with WT osteoblasts. Suppressing CD36 in osteoclast progenitors also attenuated osteoclast formation. The hypercalcemic response to a PTH infusion was blunted in CD47-/-/CD36-/- (double knockout (DKO)) female mice but not CD47-/- mice or CD36-/- animals, supporting a role for both CD47 and CD36 in mediating this effect. Consistent with this, DKO osteoclasts had impaired resorptive activity when analyzed in vitro Inhibition of nitric oxide (NO) signaling is known to promote osteoclastogenesis, and TSP-1 suppresses NO production and signaling. An anti-TSP-1 antibody increased NO production in osteoclasts, and the inhibitory effect of anti-TSP-1 on osteoclastogenesis was completely rescued by l-nitroarginine methyl ester (l-NAME), a competitive NO synthase inhibitor. Supportive of an important role for CD36 in mediating the pro-osteoclastogenic effects of TSP-1, engaging CD36 with a synthetic agonist, p907, suppressed NO production in anti-TSP-1-treated cultures, allowing osteoclast maturation to occur. These results establish that CD36 and CD47 both participate in mediating the actions of TSP-1 in osteoclasts and establish a physiologically relevant cross-talk in bone tissue between these two molecules.


Assuntos
Antígenos CD36/genética , Antígeno CD47/genética , Óxido Nítrico/biossíntese , Trombospondina 1/genética , Animais , Reabsorção Óssea/genética , Reabsorção Óssea/patologia , Antígenos CD36/química , Antígeno CD47/química , Feminino , Hipercalcemia/genética , Hipercalcemia/patologia , Proteínas de Membrana/química , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , NG-Nitroarginina Metil Éster/administração & dosagem , Óxido Nítrico Sintase/antagonistas & inibidores , Óxido Nítrico Sintase/química , Osteoclastos/química , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteogênese/genética , Hormônio Paratireóideo/química , Hormônio Paratireóideo/genética , Detecção de Sinal Psicológico , Transdução de Sinais/efeitos dos fármacos , Trombospondina 1/química
6.
Proc Natl Acad Sci U S A ; 112(19): E2477-86, 2015 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-25918418

RESUMO

Maize is a major crop and a model plant for studying C4 photosynthesis and leaf development. However, a genomewide regulatory network of leaf development is not yet available. This knowledge is useful for developing C3 crops to perform C4 photosynthesis for enhanced yields. Here, using 22 transcriptomes of developing maize leaves from dry seeds to 192 h post imbibition, we studied gene up- and down-regulation and functional transition during leaf development and inferred sets of strongly coexpressed genes. More significantly, we developed a method to predict transcription factor binding sites (TFBSs) and their cognate transcription factors (TFs) using genomic sequence and transcriptomic data. The method requires not only evolutionary conservation of candidate TFBSs and sets of strongly coexpressed genes but also that the genes in a gene set share the same Gene Ontology term so that they are involved in the same biological function. In addition, we developed another method to predict maize TF-TFBS pairs using known TF-TFBS pairs in Arabidopsis or rice. From these efforts, we predicted 1,340 novel TFBSs and 253 new TF-TFBS pairs in the maize genome, far exceeding the 30 TF-TFBS pairs currently known in maize. In most cases studied by both methods, the two methods gave similar predictions. In vitro tests of 12 predicted TF-TFBS interactions showed that our methods perform well. Our study has significantly expanded our knowledge on the regulatory network involved in maize leaf development.


Assuntos
Regulação da Expressão Gênica de Plantas , Folhas de Planta/metabolismo , Fatores de Transcrição/metabolismo , Transcriptoma , Zea mays/genética , Motivos de Aminoácidos , Arabidopsis/genética , Sítios de Ligação , Biologia Computacional , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Genoma de Planta , Família Multigênica , Oryza/genética , Fotossíntese , Regiões Promotoras Genéticas , Ligação Proteica , Transcrição Gênica
7.
Plant Cell ; 26(6): 2486-2504, 2014 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24894043

RESUMO

Male sterility plays an important role in F1 hybrid seed production. We identified a male-sterile rice (Oryza sativa) mutant with impaired pollen development and a single T-DNA insertion in the transcription factor gene bHLH142. Knockout mutants of bHLH142 exhibited retarded meiosis and defects in tapetal programmed cell death. RT-PCR and in situ hybridization analyses showed that bHLH142 is specifically expressed in the anther, in the tapetum, and in meiocytes during early meiosis. Three basic helix-loop-helix transcription factors, UDT1 (bHLH164), TDR1 (bHLH5), and EAT1/DTD1 (bHLH141) are known to function in rice pollen development. bHLH142 acts downstream of UDT1 and GAMYB but upstream of TDR1 and EAT1 in pollen development. In vivo and in vitro assays demonstrated that bHLH142 and TDR1 proteins interact. Transient promoter assays demonstrated that regulation of the EAT1 promoter requires bHLH142 and TDR1. Consistent with these results, 3D protein structure modeling predicted that bHLH142 and TDR1 form a heterodimer to bind to the EAT1 promoter. EAT1 positively regulates the expression of AP37 and AP25, which induce tapetal programmed cell death. Thus, in this study, we identified bHLH142 as having a pivotal role in tapetal programmed cell death and pollen development.

8.
Proc Natl Acad Sci U S A ; 110(10): 3979-84, 2013 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-23431200

RESUMO

Our anatomical analysis revealed that a dry maize seed contains four to five embryonic leaves at different developmental stages. Rudimentary kranz structure (KS) is apparent in the first leaf with a substantial density, but its density decreases toward younger leaves. Upon imbibition, leaf expansion occurs rapidly with new KSs initiated from the palisade-like ground meristem cells in the middle of the leaf. In parallel to the anatomical analysis, we obtained the time course transcriptomes for the embryonic leaves in dry and imbibed seeds every 6 h up to hour 72. Over this time course, the embryonic leaves exhibit transcripts of 30,255 genes at a level that can be regarded as "expressed." In dry seeds, ∼25,500 genes are expressed, showing functional enrichment in transcription, RNA processing, protein synthesis, primary metabolic pathways, and calcium transport. During the 72-h time course, ∼13,900 genes, including 590 transcription factor genes, are differentially expressed. Indeed, by 30 h postimbibition, ∼2,200 genes expressed in dry seeds are already down-regulated, and ∼2,000 are up-regulated. Moreover, the top 1% expressed genes at 54 h or later are very different from those before 30 h, reflecting important developmental and physiological transitions. Interestingly, clusters of genes involved in hormone metabolism, signaling, and responses are differentially expressed at various time points and TF gene expression is also modular and stage specific. Our dataset provides an opportunity for hypothesizing the timing of regulatory actions, particularly in the context of KS development.


Assuntos
Zea mays/embriologia , Zea mays/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Germinação/genética , Reguladores de Crescimento de Plantas/genética , Folhas de Planta/embriologia , Folhas de Planta/genética , Proteínas de Plantas/genética , RNA de Plantas/genética , Sementes/embriologia , Sementes/genética , Fatores de Transcrição/genética , Zea mays/fisiologia
9.
J Biol Chem ; 289(10): 6775-6790, 2014 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-24394418

RESUMO

Colony-stimulating factor 1 (CSF1) is known to promote osteoclast progenitor survival, but its roles in osteoclast differentiation and mature osteoclast function are less well understood. In a microarray screen, Jun dimerization protein 2 (JDP2) was identified as significantly induced by CSF1. Recent reports indicate that JDP2 is required for normal osteoclastogenesis and skeletal metabolism. Because there are no reports on the transcriptional regulation of this gene, the DNA sequence from -2612 to +682 bp (relative to the transcription start site) of the JDP2 gene was cloned, and promoter activity was analyzed. The T box-binding element (TBE) between -191 and -141 bp was identified as the cis-element responsible for CSF1-dependent JDP2 expression. Using degenerate PCR, Tbx3 was identified as the major isoform binding the TBE. Overexpression of Tbx3 induced JDP2 promoter activity, whereas suppressing Tbx3 expression substantially attenuated CSF1-induced transcription. Suppressing Tbx3 in osteoclast precursors reduced JDP2 expression and significantly impaired RANKL/CSF1-induced osteoclastogenesis. A MEK1/2-specific inhibitor was found to block CSF1-induced JDP2 expression. Consistent with these data, JDP2(-/-) mice were found to have increased bone mass. In summary, CSF1 up-regulates JDP2 expression by inducing Tbx3 binding to the JDP2 promoter. The downstream signaling cascade from activated c-Fms involves the MEK1/2-ERK1/2 pathway. Tbx3 plays an important role in osteoclastogenesis at least in part by regulating CSF1-dependent expression of JDP2.


Assuntos
Osteoclastos/fisiologia , Proteínas Repressoras/genética , Proteínas com Domínio T/metabolismo , Ativação Transcricional , Animais , Sequência de Bases , Densidade Óssea , Osso e Ossos/diagnóstico por imagem , Osso e Ossos/ultraestrutura , Ensaio de Desvio de Mobilidade Eletroforética , Fator Estimulador de Colônias de Macrófagos , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Osteoclastos/citologia , Osteoclastos/metabolismo , Regiões Promotoras Genéticas , Radiografia , Proteínas com Domínio T/genética
10.
FASEB J ; 27(6): 2476-83, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23447582

RESUMO

Iron (Fe) deficiency is endemic worldwide. Little data are available regarding acute effects of dietary protein on intestinal Fe absorption. The current study evaluated the short-term effects of increasing dietary protein on Fe absorption and expression of genes involved in Fe homeostasis. Sprague Dawley rats (24, female) were randomly assigned to custom-formulated isocaloric diets containing 40, 20 (control), or 5% protein (as percentage of total kilocalories) for 7 d. Whole-body Fe balance studies demonstrated that Fe retention was greater in the 40% group than in the 5% group (30.8 vs. 7.3%; P<0.01). In a separate study utilizing stable iron isotopes, the 40% group absorbed 30% of ingested Fe, while the 20% group absorbed 18% (P=0.005). Whole-genome profiling revealed that increasing dietary protein from 5 to 40% increased duodenal transcript expression of divalent metal transporter 1 (DMT1) 3.2-fold, duodenal cytochrome b (Dcytb) 1.8-fold, and transferrin receptor (TfR) 1.8-fold. Consistent with these findings, DMT1 transcript expression was 4-fold higher in RNA prepared from duodenal mucosa in the 40% group compared to the 20% group (P<0.001). These data suggest that increasing dietary protein increases intestinal Fe absorption in part by up-regulating DMT1, Dcytb, and TfR.


Assuntos
Proteínas de Transporte de Cátions/genética , Citocromos b/genética , Proteínas Alimentares/administração & dosagem , Absorção Intestinal/genética , Ferro da Dieta/farmacocinética , Receptores da Transferrina/genética , Regulação para Cima , Animais , Caseínas/administração & dosagem , Duodeno/metabolismo , FMN Redutase/genética , Feminino , Absorção Intestinal/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley
11.
Ying Yong Sheng Tai Xue Bao ; 35(5): 1233-1241, 2024 May.
Artigo em Zh | MEDLINE | ID: mdl-38886421

RESUMO

The alteration of stand age instigates modifications in soil properties and microbial communities. Understanding the impacts of stand age on soil enzyme stoichiometry and microbial nutrient limitations in Camellia oleifera plantation is crucial for nutrient management. Taking C. oleifera plantation across four age groups (<10 a, 15-25 a, 30-50 a, >60 a) in a subtropical red soil region as test objects, we examined the response of soil enzyme stoichiometry and microbial nutrient limitations to change in stand age and analyzed the pathways for such responses. The results showed that, compared to that of stand age <10 a, enzyme C:N in the 15-25 a was increased and enzyme N:P was significantly reduced. Microbial biomass carbon (MBC), microbial biomass nitrogen (MBN), and microbial biomass phosphorus (MBP) exhibited a trend of initially decreasing and then increasing with stand age. MBN and MBN:MBP were significantly higher in the <10 a compared to that in the 30-50 a. MBC:MBN was significantly higher in the 30-50 a and >60 a compared to the <10 a and 15-25 a. Results of redundancy analysis revealed that soil nutrients, microbial biomass and their stoichiometry explained 92.4% of the variations in enzyme stoichiometry. Partial least squares path modeling (PLS-PM) results demonstrated that soil organic carbon (SOC) had a positive effect on microbial C limitation; MBN, MBN:MBP, MBC:MBP, SOC, and total nitrogen had a nega-tive overall effect on microbial P limitation, whereas soil C:N had a positive overall effect on microbial P limitation. There was a significant positive correlation between microbial C and P limitations. With increasing stand age, microbial nutrient limitation shifted from N and P limitation (<10 a) to C and P limitation (15-25 a, 30-50 a, >60 a).


Assuntos
Camellia , Carbono , Nitrogênio , Fósforo , Microbiologia do Solo , Solo , Camellia/metabolismo , Camellia/crescimento & desenvolvimento , Camellia/química , Solo/química , Nitrogênio/metabolismo , Nitrogênio/análise , Carbono/metabolismo , Fósforo/metabolismo , Nutrientes/metabolismo , Nutrientes/análise , Fatores de Tempo , China , Biomassa
12.
Bone ; 184: 117086, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38552893

RESUMO

PURPOSE: Mitofusin 2 (Mfn2) is one of two mitofusins involved in regulating mitochondrial size, shape and function, including mitophagy, an important cellular mechanism to limit oxidative stress. Reduced expression of Mfn2 has been associated with impaired osteoblast differentiation and function and a reduction in the number of viable osteocytes in bone. We hypothesized that the genetic absence of Mfn2 in these cells would increase their susceptibility to aging-associated metabolic stress, leading to a progressive impairment in skeletal homeostasis over time. METHODS: Mfn2 was selectively deleted in vivo at three different stages of osteoblast lineage commitment by crossing mice in which the Mfn2 gene was floxed with transgenic mice expressing Cre under the control of the promoter for Osterix (OSX), collagen1a1, or DMP1 (Dentin Matrix Acidic Phosphoprotein 1). RESULTS: Mice in which Mfn2 was deleted using DMP1-cre demonstrated a progressive and dramatic decline in bone mineral density (BMD) beginning at 10 weeks of age (n = 5 for each sex and each genotype from age 10 to 20 weeks). By 15 weeks, there was evidence for a functional decline in muscle performance as assessed using a rotarod apparatus (n = 3; 2 males/ 1 female for each genotype), accompanied by a decline in lean body mass. A marked reduction in trabecular bone mass was evident on bone histomorphometry, and biomechanical testing at 25 weeks (k/o: 2 male/1 female, control 2 male/2 female) revealed severely impaired femur strength. Extensive regional myofiber atrophy and degeneration was observed on skeletal muscle histology. Electron microscopy showed progressive disruption of cellular architecture, with disorganized sarcomeres and a bloated mitochondrial reticulum. There was also evidence of neurodegeneration within the ventral horn and roots of the lumbar spinal cord, which was accompanied by myelin loss and myofiber atrophy. Deletion of Mfn2 using OSX-cre or Col1a1-cre did not result in a musculoskeletal phenotype. Where possible, male and female animals were analyzed separately, but small numbers of animals in each group limited statistical power. For other outcomes, where sex was not considered, small sample sizes might still limit the strength of the observation. CONCLUSION: Despite known functional overlap of Mfn1 and Mfn2 in some tissues, and their co-expression in bone, muscle and spinal cord, deletion of Mfn2 using the 8 kB DMP1 promoter uncovered an important non-redundant role for Mfn2 in maintaining the neuromuscular/bone axis.


Assuntos
Densidade Óssea , GTP Fosfo-Hidrolases , Animais , Feminino , GTP Fosfo-Hidrolases/metabolismo , GTP Fosfo-Hidrolases/genética , Masculino , Camundongos , Densidade Óssea/genética , Densidade Óssea/fisiologia , Camundongos Transgênicos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Osso e Ossos/patologia , Osso e Ossos/metabolismo , Junção Neuromuscular/metabolismo , Junção Neuromuscular/patologia , Osteoblastos/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética
13.
Hell J Nucl Med ; 15(3): 210-4, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23106053

RESUMO

The aim of this study was to investigate the normal values of glomerular filtration rate (GFR) by technetium-99m diaethylene-triamine-pentaacetic acid ((99m)Tc-DTPA) renal dynamic imaging for living kidney graft donors. In a total of 212 candidate donors, GFR was examined using (99m)Tc-DTPA renal dynamic imaging. Donors with GFR≥80mL/(min×1.73m(2)) and as low as with GFR≥70mL/(min×1.73m(2)) but a normal endogenous creatinine clearance rate (CCr) were quantified for living kidney donation. Differences in GFR levels based on sex and age were analyzed using rank correlation coefficient. Out of the 212 candidates, 161 were finally selected as kidney graft donors. The double kidney total GFR between the male and female donor groups, the GFR levels among differently-aged donor groups, and the GFR levels between the elderly (>55 years) and young- and middle-aged (≤55 years) donor groups did not show any significant difference (P>0.05). After kidney donation, renal function measured by blood urea nitrogen (BUN) and serum creatinine of all donors returned to normal within one week, and no serious complications were noticed. In conclusion, renal dynamic imaging by (99m)Tc-DTPA had a good accuracy and repeatability in GFR evaluation for living kidney donors. Candidate donors with GFR between 70mL/(min×1.73m(2)) and 80mL/(min×1.73m(2)) can be selected as kidney donors after strict screening. In living kidney donors GFR is not significantly correlated with age or sex.


Assuntos
Transplante de Rim/diagnóstico por imagem , Transplante de Rim/estatística & dados numéricos , Doadores Vivos/estatística & dados numéricos , Tomografia por Emissão de Pósitrons/métodos , Renografia por Radioisótopo/métodos , Pentetato de Tecnécio Tc 99m , Adulto , Distribuição por Idade , China/epidemiologia , Feminino , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Compostos Radiofarmacêuticos , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Distribuição por Sexo , Adulto Jovem
14.
Emerg Infect Dis ; 17(2): 167-72, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21291584

RESUMO

In most industrialized countries, pets are becoming an integral part of households, sharing human lifestyles, bedrooms, and beds. The estimated percentage of pet owners who allow dogs and cats on their beds is 14%-62%. However, public health risks, including increased emergence of zoonoses, may be associated with such practices.


Assuntos
Leitos , Doenças do Gato/transmissão , Doenças Transmissíveis , Transmissão de Doença Infecciosa/veterinária , Doenças do Cão/transmissão , Animais de Estimação , Zoonoses/transmissão , Animais , Doenças do Gato/etiologia , Gatos , Controle de Doenças Transmissíveis/métodos , Transmissão de Doença Infecciosa/prevenção & controle , Doenças do Cão/etiologia , Cães , Humanos , Zoonoses/etiologia
15.
Blood ; 114(16): 3413-21, 2009 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-19661269

RESUMO

Lytic bone disease in myeloma is characterized by an increase in multinucleate osteoclasts in close proximity to tumor cells. However, the nature of osteoclast precursors and the mechanisms underlying multinuclearity are less understood. Here we show that culture of myeloma cell lines as well as primary myeloma cells with human dendritic cells (DCs) but not monocytes or macrophages leads to spontaneous cell-cell fusion, which then leads to the facile formation of multinucleate bone-resorbing giant cells. Osteoclastogenesis is cell contact dependent, leading to up-regulation of thrombospondin-1 (TSP-1) in DCs. Disruption of CD47-TSP-1 interaction by TSP-1-blocking antibodies or down-regulation of CD47 on tumor cells by RNA interference abrogates tumor-induced osteoclast formation. Blockade of CD47-TSP-1 interactions also inhibits receptor activator for nuclear factor kappaB ligand- and macrophage colony-stimulating factor-induced formation of osteoclasts from human monocytes. Further, TSP-1 blockade attenuates hypercalcemia induced by parathyroid hormone in vivo. These data point to a role for CD47-TSP-1 interactions in regulating cell-fusion events involved in human osteoclast formation. They also suggest that DCs, known to be enriched in myeloma tumors, may be direct precursors for tumor-associated osteoclasts. Disruption of CD47-TSP-1 interactions or preventing the recruitment of DCs to tumors may provide novel approaches to therapy of myeloma bone disease and osteoporosis.


Assuntos
Antígeno CD47/metabolismo , Células Dendríticas/metabolismo , Mieloma Múltiplo/metabolismo , Osteólise/metabolismo , Trombospondina 1/metabolismo , Anticorpos Monoclonais/farmacologia , Fusão Celular , Linhagem Celular Tumoral , Humanos , Mieloma Múltiplo/tratamento farmacológico , NF-kappa B/metabolismo , Osteoclastos/metabolismo , Osteólise/tratamento farmacológico , Interferência de RNA
16.
PLoS One ; 16(2): e0247199, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33607650

RESUMO

The receptor for Colony Stimulating Factor 1 (CSF1), c-fms, is highly expressed on mature osteoclasts suggesting a role for this cytokine in regulating the function of these cells. Consistent with this idea, in vitro studies have documented a variety of effects of CSF1 in mature osteoclasts. To better define the role of CSF1 in these cells, we conditionally deleted c-fms in osteoclasts (c-fms-OC-/-) by crossing c-fmsflox/flox mice with mice expressing Cre under the control of the cathepsin K promoter. The c-fms-OC-/- mice were of normal weight and had normal tooth eruption. However, when quantified by DXA, bone mass was significantly higher in the spine and femur of female knock out mice and in the femurs of male knock out mice. MicroCT analyses of femurs showed that female c-fms-OC-/- mice had significantly increased trabecular bone mass with a similar trend in males and both sexes demonstrated significantly increased trabecular number and reduced trabecular spacing. Histomorphometric analysis of the femoral trabecular bone compartment demonstrated a trend towards increased numbers of osteoclasts, +26% in Noc/BPm and +22% in OcS/BS in the k/o animals but this change was not significant. However, when the cellular volume of osteoclasts was quantified, the c-fms-OC-/- cells were found to be significantly smaller than controls. Mature osteoclasts show a marked spreading response when exposed to CSF1 in a non-gradient fashion. However, osteoclasts freshly isolated from c-fms-OC-/- mice had a near complete abrogation of this response. C-fms-OC-/- mice treated with (1-34)hPTH 80 ng/kg/d in single daily subcutaneous doses for 29 days showed an attenuated anabolic response in trabecular bone compared to wild-type animals. Taken together, these data indicate an important non-redundant role for c-fms in regulating mature osteoclast function in vivo.


Assuntos
Receptor de Fator Estimulador de Colônias de Macrófagos/genética , Animais , Densidade Óssea/efeitos dos fármacos , Osso Esponjoso/diagnóstico por imagem , Osso Esponjoso/patologia , Diferenciação Celular , Feminino , Fêmur/citologia , Fêmur/metabolismo , Fêmur/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Osteoclastos/citologia , Osteoclastos/metabolismo , Osteogênese , Hormônio Paratireóideo/farmacologia , Fragmentos de Peptídeos/farmacologia , Receptor de Fator Estimulador de Colônias de Macrófagos/deficiência , Microtomografia por Raio-X
17.
Endocrinology ; 162(5)2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33640975

RESUMO

Sphingosine-1-phosphate (S1P) is an anabolic clastokine. Sphingosine kinase (SPHK) is the rate-limiting enzyme in S1P production and has 2 isoforms. To evaluate the roles of SPHK1 and SPHK2 in bone, we examined the skeletal phenotype of mice with selective deletion of SPHK1 in osteoclasts (SPHK1-Oc-/-) and mice in which the SPHK2 gene was deleted in all tissues (SPHK2-/-). SPHK1-Oc-/- had normal bone mass. By contrast, SPHK2-/- female mice had a 14% lower spinal bone mineral density (BMD; P < 0.01) and males a 22% lower BMD at the same site (P < 0.001). SPHK2-/- and control mice were subsequently treated either with daily parathyroid hormone [PTH](1-34) or vehicle for 29 days. The response to PTH was significantly attenuated in the SPHK2-/-mice. The mean femoral bone volume to total volume fraction (BV/TV) increased by 24.8% in the PTH-treated female control animals vs 10.6% in the vehicle-treated female controls (P < 0.01). In contrast, in the SPHK2-/- female mice the difference in femoral trabecular BV/TV at the end of treatment was not significant (20.5 vs13.3%, PTH vs vehicle, P = NS). The anabolic response to PTH was significantly attenuated in the spine of male SPHK2-/- mice (29.7% vs 23.1%, PTH vs vehicle, in controls, P < 0.05; 26.9% vs 19.5% PTH vs vehicle in SPHK2-/- mice, P = NS). The spine responded normally in the SPHK2-/- female mice. Interestingly, suppression of sclerostin was blunted in the SPHK2-/- mice when those animals were treated with an anabolic PTH regimen. We conclude that SPHK2 has an important role in mediating both normal bone remodeling and the anabolic response to PTH.


Assuntos
Anabolizantes/metabolismo , Fêmur/metabolismo , Hormônio Paratireóideo/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/metabolismo , Coluna Vertebral/metabolismo , Animais , Densidade Óssea , Feminino , Fêmur/química , Masculino , Camundongos , Camundongos Knockout , Osteoclastos/metabolismo , Fosfotransferases (Aceptor do Grupo Álcool)/genética , Coluna Vertebral/química
18.
J Clin Microbiol ; 48(2): 539-44, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20007380

RESUMO

Cryptococcus gattii emerged in North America in 1999 as a human and veterinary pathogen on Vancouver Island, British Columbia. The emergent subtype, VGIIa, and the closely related subtype VGIIb can now be found in the United States in Washington, Oregon, and California. We performed multilocus sequence typing and antifungal susceptibility testing on 43 isolates of C. gattii from human patients in Oregon, Washington, California, and Idaho. In contrast to Vancouver Island, VGIIa was the most frequent but not the predominant subtype in the northwest United States. Antifungal susceptibility testing showed statistically significant differences in MICs between the subtypes. This is the first study to apply antifungal susceptibility testing to C. gattii isolates from the Pacific Northwest and the first to make direct comparisons between subtypes.


Assuntos
Antifúngicos/farmacologia , Criptococose/microbiologia , Criptococose/veterinária , Cryptococcus gattii/efeitos dos fármacos , Cryptococcus gattii/genética , DNA Fúngico/genética , Farmacorresistência Fúngica , Animais , Cryptococcus gattii/isolamento & purificação , Impressões Digitais de DNA , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Dados de Sequência Molecular , Técnicas de Tipagem Micológica , Noroeste dos Estados Unidos , Análise de Sequência de DNA
19.
Nat Commun ; 11(1): 1546, 2020 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-32210234

RESUMO

Calcium orthophosphates (CaPs) are important in geology, biomineralization, animal metabolism and biomedicine, and constitute a structurally and chemically diverse class of minerals. In the case of dicalcium phosphates, ever since brushite (CaHPO4·2H2O, dicalcium phosphate dihydrate, DCPD) and monetite (CaHPO4, dicalcium phosphate, DCP) were first described in 19th century, the form with intermediary chemical formula CaHPO4·H2O (dicalcium phosphate monohydrate, DCPM) has remained elusive. Here, we report the synthesis and crystal structure determination of DCPM. This form of CaP is found to crystallize from amorphous calcium hydrogen phosphate (ACHP) in water-poor environments. The crystal structure of DCPM is determined to show a layered structure with a monoclinic symmetry. DCPM is metastable in water, but can be stabilized by organics, and has a higher alkalinity than DCP and DCPD. This study serves as an inspiration for the future exploration of DCPM's potential role in biomineralization, or biomedical applications.


Assuntos
Biomineralização , Fosfatos de Cálcio/química , Animais , Linhagem Celular , Cristalização , Células-Tronco Mesenquimais , Metanol/química , Simulação de Dinâmica Molecular , Ratos , Solventes/química , Água/química , Difração de Raios X
20.
J Wildl Dis ; 45(1): 227-33, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19204355

RESUMO

Scenario-based analyses were computed for benefits and costs linked with hypothetical oral rabies vaccination (ORV) campaigns to contain or eliminate skunk-variant rabies in skunks (Mephitis mephitis) in California, USA. Scenario 1 assumed baiting eight zones (43,388 km(2) total) that comprised 73% of known skunk rabies locations in the state. Scenario 2 also assumed baiting these eight zones, but further assumed that added benefits would result from preventing the spread of skunk-variant rabies into Los Angeles County, USA. Scenarios assumed a fixed bait cost ($1.24 each) but varied campaigns (one, two and three annual ORV applications), densities of baits (37.5/km(2), 75/km(2) and 150/km(2)), levels of prevention (50%, 75%, and 100%), and contingency expenditures if rabies recurred (20%, 40%, and 60% of campaign costs). Prorating potential annual benefits during a 12-yr time horizon yielded benefit-cost ratios (BCRs) between 0.16 and 2.91 and between 0.34 and 6.35 for Scenarios 1 and 2, respectively. Economic issues relevant to potentially managing skunk-variant rabies with ORV are discussed.


Assuntos
Análise Custo-Benefício , Surtos de Doenças/veterinária , Mephitidae/virologia , Vacina Antirrábica/economia , Raiva/veterinária , Administração Oral , Animais , Animais Selvagens/virologia , California/epidemiologia , Surtos de Doenças/economia , Surtos de Doenças/prevenção & controle , Feminino , Masculino , Raiva/economia , Raiva/epidemiologia , Raiva/prevenção & controle , Vacina Antirrábica/administração & dosagem , Vírus da Raiva/imunologia
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