Publications by authors named "Mai Xiong"

21 Publications

  • Page 1 of 1

Hypofractionated Intensity Modulated Radiation Therapy With Concurrent Chemotherapy in Locally Advanced Non-Small Cell Lung Cancer: A Phase II Prospective Clinical Trial (GASTO1011).

Pract Radiat Oncol 2021 Jun 19. Epub 2021 Jun 19.

Department of Radiation Oncology, Sun Yat-sen University Cancer Center, Guangzhou; State Key Laboratory of Oncology in South China, Sun Yat-sen University Cancer Center, Guangzhou; Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou; Lung Cancer Institute of Sun Yat-sen University, Guangzhou.; Guangdong Association Study of Thoracic Oncology, Guangzhou. Electronic address:

Purpose: We aimed to explore the efficacy and toxicity of split-course hypofractionated radiotherapy with concurrent chemotherapy (HRT-CHT) in patients with locally advanced non-small cell lung cancer (LANSCLC) in this single-arm, phase II study.

Methods: LANSCLC patients were considered eligible if their forced expiratory volume in 1 second/forced vital capacity (FEV1/FVC%) and carbon monoxide diffusing capacity (DLCO%) were ≥40% and ≥45%, respectively. HRT-CHT using the IMRT technique was administered with 51 Gy in 17 fractions as the first course followed by a break. Patients without disease progression or persistent ≥grade 2 toxicities had an HRT-CHT of 15-18 Gy in 5-6 fractions as a boost. The primary endpoint was progression-free survival (PFS), and the secondary endpoint was overall survival (OS).

Results: Eighty-nine patients were enrolled and analyzed. The median follow-up was 29.5 months for all patients and 35.3 months for the survivors. The objective response rate was 97.8%; the median PFS and OS were 11.0 months and 27.0 months, respectively. Grade 3 acute esophagitis/pneumonitis occurred in 15 (16.9%)/7 (7.9%) patients. Grade 3/5 late pneumonitis occurred in 2 (2.2%)/1 (1.1%) patients. Of the 78 (87.6%) who completed the split-course HRT-CHT per protocol, patients with better FEV1/FVC% and DLCO% after the break had significantly better OS (for the FEV/FVC1%≥80% vs 60-79% vs 41-59% groups, 2-year OS values were 57.2% vs 56.9% vs 0%, respectively, p=0.024; for the DLCO%≥80% vs 60-79% vs 45-59% groups, 2-year OS values were 70.4% vs 48.4% vs 37.5%, respectively, p=0.049).

Conclusions: Split-course HRT-CHT achieved a promising response rate and survival with tolerable toxicity in LANSCLC. Pulmonary function tests are necessary indicators for radiation treatment planning and dose escalation.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.prro.2021.06.004DOI Listing
June 2021

Hypo-fractionated radiotherapy with concurrent chemotherapy for locoregional recurrence of non-small cell lung cancer after complete resection: A prospective, single-arm, phase II study (GASTO-1017).

Lung Cancer 2021 06 27;156:82-90. Epub 2021 Apr 27.

Department of Radiation Oncology, State Key Laboratory of Oncology in South China, Collaborative Innovation Center for Cancer Medicine, Sun Yat-sen University Cancer Center, Guangzhou, China; Lung Cancer Institute of Sun Yat-sen University, Guangzhou, China; Guangdong Association Study of Thoracic Oncology, Guangzhou, China. Electronic address:

Objectives: To explore the efficacy and toxicities of split-course hypo-fractionated radiotherapy with concurrent chemotherapy (HFRT-CHT) with intensity modulated radiotherapy (IMRT) technique in non-small cell lung cancer (NSCLC) patients with postoperative locoregional recurrence (LRR).

Materials And Methods: NSCLC patients were eligible if confirmed as LRR disease without distant metastasis after complete resection. HFRT-CHT using IMRT technique was administered with 51 Gy in 17 fractions or 40 Gy in 10 fractions as the first course followed by a break. Patients with no disease progression and no persistent Grade ≥2 toxicities had the second course of 15 Gy in 5 fractions or 28 Gy in 7 fractions as a boost. The primary endpoint was progression-free survival (PFS).

Results: Fifty-eight patients were enrolled and analyzed. With a median follow-up of 23.9 months for all, the 2-year and 3-year PFS rate was 59.7 % and 46.4 %, the 2-year and 3-year OS rate was 72.5 % and 52.2 %, respectively, and a favorable objective response rate of 95.9 % was obtained after the whole courses protocol. Grade 3 acute pneumonitis and esophagitis occurred in 2 (3.4 %) and 7 (12.1 %) patients, and fatal pneumonitis was reported in one case (1.7 %). Exploratory subgroup analysis showed that performance status (PS) (PS 0 vs. 1: 2-year PFS, 88.1 % vs. 46.9 %,P = 0.001; 2-year OS, 100 % vs. 59.4 %, P < 0.001), recurrence site (single vs. multiple: 2-year PFS, 93.8 % vs. 47.4 %, P = 0.008; 2-year OS, 100 % vs. 63.0 %, P = 0.001), and gross tumor volume (GTV) (<50cm vs. ≥ 50cm: 2-year PFS, 70.6 % vs. 46.2 %, P = 0.024; 2-year OS, 85.6 % vs. 57.4 %, P = 0.034) were significantly associated with PFS and OS.

Conclusion: Split-course HFRT-CHT with IMRT technique achieved promising disease control and satisfactory survival with moderate toxicities in postoperative LRR of NSCLC. Good PS, a single recurrence site and GTV<50cm tended to have prolonged PFS and OS. Early detection of LRR may improve the efficacy of HFRT-CHT.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.lungcan.2021.04.020DOI Listing
June 2021

Increased glucose variability is associated with major adverse events in patients with infective endocarditis undergo surgical treatment.

J Thorac Dis 2021 Feb;13(2):653-663

Department of Cardiac Surgery, the First Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.

Background: This study aimed to investigate the prognostic value of glucose variability (GV) in predicting postoperative major adverse events (MAEs) in patients with infective endocarditis (IE) who underwent surgical treatment.

Methods: This retrospective observational study included a total of 381 consecutive patients who underwent surgical treatment in our institution from October 2007 to August 2019. The MAEs included all-cause death, stroke, myocardial infarction, acute heart failure, IE recurrence, acute renal failure and sepsis. Postoperative GV in the first 24 hours was measured by the mean 24-hour glucose, standard deviation, coefficient of variation (CV) and mean amplitude of glycemic excursions. Univariate and multivariate logistic regression analyses were performed to identify the independent association of GV with MAEs.

Results: Of the 381 patients, 79 (20.7%) developed MAEs. The 30-day mortality of the overall study cohort was 5.23%. The multivariate logistic regression analysis indicated that 24-hour GV, measured as the CV [odds ratio (OR) =1.49, 95% CI, 1.23-3.57, P=0.012], was significantly associated with MAEs in IE patients. For every 10% increase in 24-hour CV, there was a 49% increase in the risk of MAEs. Furthermore, compared to patients in the low tertile of GV, patients in the top tertile of 24-hour GV had a higher 30-day mortality and an increased incidence of heart failure and hemodialysis as well as longer ventilation support.

Conclusions: The results of this retrospective investigation demonstrated that increased GV measured by CV is an independent predictor of postoperative MAEs in patients undergoing surgical treatment for IE.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.21037/jtd-20-2692DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7947509PMC
February 2021

Genomic Sequencing for Newborn Screening: Results of the NC NEXUS Project.

Am J Hum Genet 2020 10 26;107(4):596-611. Epub 2020 Aug 26.

Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. Electronic address:

Newborn screening (NBS) was established as a public health program in the 1960s and is crucial for facilitating detection of certain medical conditions in which early intervention can prevent serious, life-threatening health problems. Genomic sequencing can potentially expand the screening for rare hereditary disorders, but many questions surround its possible use for this purpose. We examined the use of exome sequencing (ES) for NBS in the North Carolina Newborn Exome Sequencing for Universal Screening (NC NEXUS) project, comparing the yield from ES used in a screening versus a diagnostic context. We enrolled healthy newborns and children with metabolic diseases or hearing loss (106 participants total). ES confirmed the participant's underlying diagnosis in 15 out of 17 (88%) children with metabolic disorders and in 5 out of 28 (∼18%) children with hearing loss. We discovered actionable findings in four participants that would not have been detected by standard NBS. A subset of parents was eligible to receive additional information for their child about childhood-onset conditions with low or no clinical actionability, clinically actionable adult-onset conditions, and carrier status for autosomal-recessive conditions. We found pathogenic variants associated with hereditary breast and/or ovarian cancer in two children, a likely pathogenic variant in the gene associated with Lowe syndrome in one child, and an average of 1.8 reportable variants per child for carrier results. These results highlight the benefits and limitations of using genomic sequencing for NBS and the challenges of using such technology in future precision medicine approaches.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ajhg.2020.08.001DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7536575PMC
October 2020

Sleep medicine durable medical equipment management during the COVID-19 pandemic: our center's initial experience.

J Clin Sleep Med 2020 09;16(9):1637-1638

Division of Pulmonary, Critical Care and Sleep Medicine, University of Minnesota Medical School, Minneapolis, Minnesota.

View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.5664/jcsm.8638DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7970592PMC
September 2020

Chylothorax and constrictive pericarditis in a woman due to generalized lymphatic anomaly: a case report.

J Cardiothorac Surg 2018 Jun 5;13(1):59. Epub 2018 Jun 5.

Department of Respiratory Medicine, The First Affiliated Hospital, Sun Yat-sen University, No 58, Zhongshan 2nd Road, Guangzhou, 510080, China.

Background: Generalized lymphatic anomaly (GLA) is characterized by diffuse or multicentric proliferation of dilated lymphatic vessels resembling common lymphatic malformations. Compared with soft tissue or bone involvement, thoracic involvement may be associated with a worse prognosis.

Case Presentation: We reported a case of GLA with chylothorax and constrictive pericarditis in a 29-year-old woman. This patient exhibited remarkable features, including a continuously hemorrhagic chylothorax, constrictive pericarditis, and involvement of bone and neck lymph nodes. After attempting to manage her condition with conservative treatment, the patient underwent pericardial stripping surgery. Exploration revealed abundant hyperplasia of tubular tissue in the aortopulmonary window in both pleural cavities.

Conclusions: This case highlights the importance of maintaining the clinical suspicion of GLA during the follow-up of chylothorax patients. Aggressive pericardial surgery, which is important for both diagnosis and treatment, should be performed in patients with GLA with constrictive pericarditis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1186/s13019-018-0752-3DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5989411PMC
June 2018

Somali, Latino and Hmong parents' perceptions and approaches about raising healthy-weight children: a community-based participatory research study.

Public Health Nutr 2018 04 14;21(6):1079-1093. Epub 2017 Aug 14.

2Somali,Latino, and Hmong Partnership for Health and Wellness (SoLaHmo),West Side Community Health Services,Saint Paul,MN,USA.

Objective: Immigrants in the USA are confronted with health disparities, including childhood obesity and obesity-related chronic diseases. We aimed to identify perceptions of childhood body weight, approaches to raising healthy children and desires for supportive programmes of Somali, Latino and Hmong (SLM) parents in the Twin Cities, Minnesota, USA.

Design: Using community-based participatory research, ten focus groups (FG) were conducted with sixty-seven parents (n 28 Somali, three FG; n 19 Latino, four FG; n 20 Hmong, three FG) of 3-12-year-old children in their native language. Demographic information was collected.

Results: SLM parents perceived that health is not necessarily weight-based; childhood obesity is caused by overeating, eating unhealthy foods and sedentary activities; traditional foods are generally healthy while American foods are generally unhealthy; and healthy children are inherently physically active. Parents identified their goals as feeding children so they would be healthy and happy, helping them be active and safe, and teaching them to cook traditional foods to be self-sufficient and maintain their cultural identity. Parents were challenged by children's unhealthy food and sedentary preferences, their own uncertainties about healthy foods and behaviours, and structural factors. Parents thought interventions could help them with these challenges, including information about healthy foods, age-appropriate portion sizes, safe places to be active and strategies tailored to their cultural norms.

Conclusions: SLM parents are trying to raise healthy-weight children based on their understanding of children's health, weight, diet and physical activity, while dealing with social, economic and environmental challenges and trying to maintain cultural identity and traditions.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1017/S1368980017001719DOI Listing
April 2018

Large left circumflex coronary artery with a fistula to superior vena cava: Diagnosis by echocardiography.

Echocardiography 2017 Apr 1;34(4):617-620. Epub 2017 Mar 1.

Department of Cardiac Surgery, First Affiliated Hospital, Sun Yat-sen University, Guangzhou City, China.

The left circumflex coronary artery associated with a fistula to superior vena cava is a rare entity. We describe a 7-year-old girl who presented with a cardiac murmur and was diagnosed with a coronary artery fistula between the left circumflex artery and superior vena cava by echocardiography. The surgical occlusion of the fistula was successful.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1111/echo.13481DOI Listing
April 2017

Heading Date QTL in Winter Wheat (Triticum aestivum L.) Coincide with Major Developmental Genes VERNALIZATION1 and PHOTOPERIOD1.

PLoS One 2016 10;11(5):e0154242. Epub 2016 May 10.

Department of Crop Science, North Carolina State University, Raleigh, North Carolina, 27695, United States of America.

In wheat (Triticum aestivum L.), time from planting to spike emergence is influenced by genes controlling vernalization requirement and photoperiod response. Characterizing the available genetic diversity of known and novel alleles of VERNALIZATION1 (VRN1) and PHOTOPERIOD1 (PPD1) in winter wheat can inform approaches for breeding climate resilient cultivars. This study identified QTL for heading date (HD) associated with multiple VRN1 and PPD1 loci in a population developed from a cross between two early flowering winter wheat cultivars. When the population was grown in the greenhouse after partial vernalization treatment, major heading date QTLs co-located with the VRN-A1 and VRN-B1 loci. Copy number variation at the VRN-A1 locus influenced HD such that RIL having three copies required longer cold exposure to transition to flowering than RIL having two VRN-A1 copies. Sequencing vrn-B1 winter alleles of the parents revealed multiple polymorphisms in the first intron that were the basis of mapping a major HD QTL coinciding with VRN-B1. A 36 bp deletion in the first intron of VRN-B1 was associated with earlier HD after partial vernalization in lines having either two or three haploid copies of VRN-A1. The VRN1 loci interacted significantly and influenced time to heading in field experiments in Louisiana, Georgia and North Carolina. The PPD1 loci were significant determinants of heading date in the fully vernalized treatment in the greenhouse and in all field environments. Heading date QTL were associated with alleles having large deletions in the upstream regions of PPD-A1 and PPD-D1 and with copy number variants at the PPD-B1 locus. The PPD-D1 locus was determined to have the largest genetic effect, followed by PPD-A1 and PPD-B1. Our results demonstrate that VRN1 and PPD1 alleles of varying strength allow fine tuning of flowering time in diverse winter wheat growing environments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0154242PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4862677PMC
July 2017

Potential for microbial oxidation of ferrous iron in basaltic glass.

Astrobiology 2015 May 27;15(5):331-40. Epub 2015 Apr 27.

Department of Geoscience, University of Wisconsin, and NASA Astrobiology Institute, University of Wisconsin, Madison, Wisconsin.

Basaltic glass (BG) is an amorphous ferrous iron [Fe(II)]-containing material present in basaltic rocks, which are abundant on rocky planets such as Earth and Mars. Previous research has suggested that Fe(II) in BG can serve as an energy source for chemolithotrophic microbial metabolism, which has important ramifications for potential past and present microbial life on Mars. However, to date there has been no direct demonstration of microbially catalyzed oxidation of Fe(II) in BG. In this study, three different culture systems were used to investigate the potential for microbial oxidation of Fe(II) in BG, including (1) the chemolithoautotrophic Fe(II)-oxidizing, nitrate-reducing "Straub culture"; (2) the mixotrophic Fe(II)-oxidizing, nitrate-reducing organism Desulfitobacterium frappieri strain G2; and (3) indigenous microorganisms from a streambed Fe seep in Wisconsin. The BG employed consisted of clay and silt-sized particles of freshly quenched lava from the TEB flow in Kilauea, Hawaii. Soluble Fe(II) or chemically reduced NAu-2 smectite (RS) were employed as positive controls to verify Fe(II) oxidation activity in the culture systems. All three systems demonstrated oxidation of soluble Fe(II) and/or structural Fe(II) in RS, whereas no oxidation of Fe(II) in BG material was observed. The inability of the Straub culture to oxidize Fe(II) in BG was particularly surprising, as this culture can oxidize other insoluble Fe(II)-bearing minerals such as biotite, magnetite, and siderite. Although the reason for the resistance of the BG toward enzymatic oxidation remains unknown, it seems possible that the absence of distinct crystal faces or edge sites in the amorphous glass renders the material resistant to such attack. These findings have implications with regard to the idea that Fe(II)-Si-rich phases in basalt rocks could provide a basis for chemolithotrophic microbial life on Mars, specifically in neutral-pH environments where acid-promoted mineral dissolution and utilization of dissolved Fe(II) as an energy source is not likely to take place.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1089/ast.2014.1233DOI Listing
May 2015

Genome-wide association study reveals novel quantitative trait Loci associated with resistance to multiple leaf spot diseases of spring wheat.

PLoS One 2014 30;9(9):e108179. Epub 2014 Sep 30.

Center for Integrated Pest Management and Department of Plant Pathology, North Carolina State University, Raleigh, North Carolina, United States of America.

Accelerated wheat development and deployment of high-yielding, climate resilient, and disease resistant cultivars can contribute to enhanced food security and sustainable intensification. To facilitate gene discovery, we assembled an association mapping panel of 528 spring wheat landraces of diverse geographic origin for a genome-wide association study (GWAS). All accessions were genotyped using an Illumina Infinium 9K wheat single nucleotide polymorphism (SNP) chip and 4781 polymorphic SNPs were used for analysis. To identify loci underlying resistance to the major leaf spot diseases and to better understand the genomic patterns, we quantified population structure, allelic diversity, and linkage disequilibrium. Our results showed 32 loci were significantly associated with resistance to the major leaf spot diseases. Further analysis identified QTL effective against major leaf spot diseases of wheat which appeared to be novel and others that were previously identified by association analysis using Diversity Arrays Technology (DArT) and bi-parental mapping. In addition, several identified SNPs co-localized with genes that have been implicated in plant disease resistance. Future work could aim to select the putative novel loci and pyramid them in locally adapted wheat cultivars to develop broad-spectrum resistance to multiple leaf spot diseases of wheat via marker-assisted selection (MAS).
View Article and Find Full Text PDF

Download full-text PDF

Source
http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0108179PLOS
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4182470PMC
June 2015

Fe-phyllosilicate redox cycling organisms from a redox transition zone in Hanford 300 Area sediments.

Front Microbiol 2013 16;4:388. Epub 2013 Dec 16.

Department of Geoscience, University of Wisconsin Madison Madison, WI, USA.

Microorganisms capable of reducing or oxidizing structural iron (Fe) in Fe-bearing phyllosilicate minerals were enriched and isolated from a subsurface redox transition zone at the Hanford 300 Area site in eastern Washington, USA. Both conventional and in situ "i-chip" enrichment strategies were employed. One Fe(III)-reducing Geobacter (G. bremensis strain R1, Deltaproteobacteria) and six Fe(II) phyllosilicate-oxidizing isolates from the Alphaproteobacteria (Bradyrhizobium japonicum strains 22, is5, and in8p8), Betaproteobacteria (Cupriavidus necator strain A5-1, Dechloromonas agitata strain is5), and Actinobacteria (Nocardioides sp. strain in31) were recovered. The G. bremensis isolate grew by oxidizing acetate with the oxidized form of NAu-2 smectite as the electron acceptor. The Fe(II)-oxidizers grew by oxidation of chemically reduced smectite as the energy source with nitrate as the electron acceptor. The Bradyrhizobium isolates could also carry out aerobic oxidation of biotite. This is the first report of the recovery of a Fe(II)-oxidizing Nocardioides, and to date only one other Fe(II)-oxidizing Bradyrhizobium is known. The 16S rRNA gene sequences of the isolates were similar to ones found in clone libraries from Hanford 300 sediments and groundwater, suggesting that such organisms may be present and active in situ. Whole genome sequencing of the isolates is underway, the results of which will enable comparative genomic analysis of mechanisms of extracellular phyllosilicate Fe redox metabolism, and facilitate development of techniques to detect the presence and expression of genes associated with microbial phyllosilicate Fe redox cycling in sediments.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2013.00388DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3863755PMC
December 2013

Simvastatin attenuates pulmonary vascular remodelling by down-regulating matrix metalloproteinase-1 and -9 expression in a carotid artery-jugular vein shunt pulmonary hypertension model in rats.

Eur J Cardiothorac Surg 2012 Nov;42(5):e121-7

Department of Paediatric and Congenital Cardiac Surgery, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China.

Objectives: It remains controversial as to whether simvastatin has a beneficial effect on pulmonary artery hypertension. This study aimed to explore the efficacy of simvastatin on haemodynamic changes, pulmonary vascular remodelling and expression of matrix metalloproteinase-1 and -9 (MMP-1,9) in a carotid artery-jugular vein (CA-JV) shunt pulmonary artery hypertension (PAH) model in rats.

Methods: Thirty-six Sprague-Dawley rats were randomized into three groups: Control group, CA-JV group, and Treatment group. A pre-tricuspid systemic-pulmonary shunt from the left common carotid artery to the external jugular vein was established on the CA-JV and Treatment groups, but only ligations of both vessels were performed in Control group. Simvastatin (4 mg/kg/d) was administered to the Treatment group, and placebo to the CA-JV group. Twelve weeks later, the animals underwent a haemodynamic evaluation, followed by pulmonary tissue sampling for morphometry, quantitative real-time PCR and Western blot analysis.

Results: By week 12, rats in the CA-JV group had higher right ventricular systolic pressure (RVSP), medial area/total area (MA/TA) and percentage of fibrous tissue (F%) than those in the Control group. These changes were associated with up-regulation of MMP-1,9 mRNA and increased expression of MMP-1,9 proteins. Pretreatment with simvastatin decreased the shunt-induced RVSP, MA/TA and F% in pulmonary arteries. In addition, lung MMP-1,9 mRNA and proteins levels decreased toward normal levels in simvastatin-treated rats.

Conclusions: Simvastatin ameliorated the structural and functional derangements of pulmonary arterioles caused by the CA-JV shunt, partly associated with the suppression of up-regulated MMP-1, as well as MMP-9. Simvastatin may play a role in the treatment of systemic-pulmonary shunt-induced PAH diseases, such as congenital heart disease.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1093/ejcts/ezs445DOI Listing
November 2012

Isolation of phyllosilicate-iron redox cycling microorganisms from an illite-smectite rich hydromorphic soil.

Front Microbiol 2012 4;3:134. Epub 2012 Apr 4.

Department of Geoscience, University of Wisconsin-Madison Madison, WI, USA.

The biogeochemistry of phyllosilicate-Fe redox cycling was studied in a Phalaris arundinacea (reed canary grass) dominated redoximorphic soil from Shovelers Sink, a small glacial depression near Madison, WI. The clay size fraction of Shovelers Sink soil accounts for 16% of the dry weight of the soil, yet contributes 74% of total Fe. The dominant mineral in the clay size fraction is mixed layer illite-smectite, and in contrast to many other soils and sediments, Fe(III) oxides are present in low abundance. We examined the Fe biogeochemistry of Shovelers Sink soils, estimated the abundance of Fe redox cycling microorganisms, and isolated in pure culture representative phyllosilicate-Fe oxidizing and reducing organisms. The abundance of phyllosilicate-Fe reducing and oxidizing organisms was low compared to culturable aerobic heterotrophs. Both direct isolation and dilution-to-extinction approaches using structural Fe(II) in Bancroft biotite as a Fe(II) source, and O(2) as the electron acceptor, resulted in recovery of common rhizosphere organisms including Bradyrhizobium spp. and strains of Cupriavidus necator and Ralstonia solanacearum. In addition to oxidizing biotite and soluble Fe(II) with O(2), each of these isolates was able to oxidize Fe(II) in reduced NAu-2 smectite with [Formula: see text] as the electron acceptor. Oxidized NAu-2 smectite or amorphous Fe(III) oxide served as electron acceptors for enrichment and isolation of Fe(III)-reducing microorganisms, resulting in recovery of a strain related to Geobacter toluenoxydans. The ability of the recovered microorganisms to cycle phyllosilicate-Fe was verified in an experiment with native Shovelers Sink clay. This study confirms that Fe in the native Shovelers Sink clay is readily available for microbial redox transformation and can be cycled by the Fe(III)-reducing and Fe(II)-oxidizing microorganisms recovered from the soil.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.3389/fmicb.2012.00134DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3318192PMC
October 2012

Fibrosis of pulmonary vascular remodeling in carotid artery-jugular vein shunt pulmonary artery hypertension model of rats.

Eur J Cardiothorac Surg 2012 Jan;41(1):162-6

Department of Cardiac Surgery, the 1st Affiliated Hospital of Sun Yat-Sen University, Guangzhou, PR China.

Objective: The aim of the present study was to observe the changes of hemodynamics, stereology in pulmonary vascular remodeling and messenger RNA (mRNA) expressions of transforming growth factor beta 1, and receptors in carotid artery-jugular vein (CA-JV) shunt pulmonary artery hypertension model of rats.

Methods: Thirty-six Sprague-Dawley rats were randomized into three groups: CA-JV group, monocrotaline (MCT) administration group, and control group. Left CA-JV shunts were established in CA-JV group. Dorsal subcutaneous injections of MCT (60 mg kg(-1)) were received in MCT group. Ligations of left common carotid artery and external jugular vein were performed in control group. Right ventricular systolic pressure (RVSP) measurement, histological evaluation of the pulmonary tissue, and mRNA levels of transforming growth factor beta 1 (TGFß1), receptor 1 and receptor 2, were investigated after 6 weeks on MCT group, and after 12 weeks on both control and CA-JV groups.

Results: Compared with control group, RVSP, percentage of fibrous tissue (F%) in pulmonary arterioles, mRNA levels of TGFß1, and receptors of CA-JVand MCT groups increased significantly. Severe hemodynamics change was found in MCT groups. On the other hand, CA-JV group demonstrated more obvious fibrogenesis and TGFß1 signals' upregulation in two pulmonary artery hypertension (PAH) models.

Conclusions: CA-JV shunt model of rats was a well-established PAH animal model simulating congenital heart disease with systemic-pulmonary shunt.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ejcts.2011.04.031DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3241121PMC
January 2012

Atraumatic extraction of a non-vital tooth in a patient receiving long-term oral bisphosphonates.

Northwest Dent 2010 Jul-Aug;89(4):27-33

Hennepin County Medical Center, General Practice Residency, Oral and Maxillofacial Surgery, Minneapolis, Minnesota, USA.

View Article and Find Full Text PDF

Download full-text PDF

Source
October 2010

Aortic arch reconstruction with an autologous pulmonary arterial-roll tube in an interrupted aortic arch.

Heart Surg Forum 2009 Dec;12(6):E371-3

Department of Cardiac Surgery, First Affiliated Hospital of Sun Yat-San University, Guang Zhou, 510080, China.

We report a case of aortic arch reconstruction with an autologous pulmonary arterial-roll tube in a 4-year-old child with a type A interrupted aortic arch. The autologous pulmonary arterial-roll tube dilated progressively after the operation, and some severe complications occurred, including formation of an aneurysm. A second operation was performed to resect the aortic aneurysm and to interpose a Dacron tube graft. We conclude that the aforementioned dilation may limit the use of an autologous pulmonary arterial-roll tube in the construction of the aortic arch.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1532/HSF98.20091073DOI Listing
December 2009

Heart-lung transplantation for end-stage heart disease with Eisenmenger's syndrome: report of two cases.

Chin Med J (Engl) 2009 Sep;122(18):2189-92

Department of Cardiac Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou, Guangdong 510080, China.

View Article and Find Full Text PDF

Download full-text PDF

Source
September 2009

Studies on pentoxifylline and tocopherol combination for radiation-induced heart disease in rats.

Int J Radiat Oncol Biol Phys 2009 Apr;73(5):1552-9

State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, P.R. China.

Purpose: To investigate whether the application of pentoxifylline (PTX) and tocopherol l (Vit. E) could modify the development of radiation-induced heart disease and downregulate the expression of transforming growth factor (TGF)-beta1mRNA in rats.

Methods And Materials: A total of 120 Sprague-Dawley rats were separated into four groups: control group, irradiated group, experimental group 1, and experiment group 2. Supplementation was started 3 days before irradiation; in experimental group 1, injection of PTX (15 mg/kg/d) and Vit. E (5.5 mg/kg/d) continued till the 12th week postirradiation, whereas in experimental group 2 it was continued until the 24th week postirradiation. All rats were administrated a single dose of 20 Gy irradiation to the heart except the control group. Histopathologic evaluation was performed at various time points (Days 1, 2, 4, 8, and 12 and 24th week) up to 24 weeks after irradiation. Changes of levels of TGF-beta1 mRNA expression were also investigated at the same time points using competitive polymerase chain reaction.

Results: Compared with the irradiated group, levels of TGF-beta1 mRNA of the rat hearts were relatively low in the two experimental groups on the 12th week postirradiation. In experimental group 1, there was a rebound expression of TGF-beta1 mRNA on the 24th week postirradiation, whereas that of the experimental group 2 remained low (p < 0.05). The proportions of collagen fibers of the two experimental groups were lower than that of irradiated group (p < 0.05). A rebound could be observed in the experimental group 1.

Conclusion: PTX and Vit. E downregulated the expression of TGF-beta1 mRNA. The irradiated rat hearts showed a marked pathologic response to the drugs. The withdrawal of drugs in the 12th week postirradiation could cause rebound effects of the development of fibrosis.
View Article and Find Full Text PDF

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.ijrobp.2008.12.005DOI Listing
April 2009

[Correlation of TGF-beta1 mRNA expression to irradiation-induced heart damage in rats].

Ai Zheng 2008 Jan;27(1):18-24

State Key Laboratory of Oncology in South China, Guangzhou, Guangdong, PR China.

Background & Objective: Radiation-induced heart damage is one of the prognostic factors of the patients who had received radiation to the mediastinum. This study was to investigate the correlation of transforming growth factor-beta1 (TGF-beta1) mRNA expression to the radiation response of the heart in rats, in order to provide references for further study on irradiation-induced heart damage.

Methods: Sixty Sprague-Dawley rats were divided into 2 groups: the 30 rats in irradiation group were irradiated with 20 Gy on the heart; the 30 rats in control group received no irradiation. At each time point of the 1st day, the 2nd, 4th, 8th 12th, and 24th week after irradiation, 5 rats in each group were killed. The serum levels of cardiac troponin and isoenzyme of creatine kinase (CK-MB) were detected. The expression of TGF-beta1 mRNA was detected by polymerase chain reaction (PCR). Heart damage was observed with Masson staining under microscope.

Results: The serum level of cardiac troponin was elevated at 24 h after irradiation, and reached the peak at 2 weeks after irradiation, which was significantly higher than that in control group [(0.73+/-0.11) ng/mL vs. (0.11+/-0.04) ng/mL, P<0.05]. There was no significant difference in the serum level of CK-MB between two groups (P>0.05). The expression of TGF-beta1 mRNA was elevated at the 1st day after irradiation, and reached peaks at 2 and 12 weeks after irradiation, which were significantly higher than those in control group [(8.55+/-1.19)x10(-8) microg/mL vs. (1.27+/-0.11)x10(-8) microg/mL, (4.63+/-0.41)x10(-8) microg/mL vs. (1.35+/-0.15)x10(-8) microg/mL, P<0.05]. The proportion of collagen fibers was increased since 2 weeks after irradiation, which was significantly higher than that in control group [(2.87+/-0.37)% vs. (1.14+/-0.55)%, P<0.05]. The expression of TGF-beta1 mRNA was positively correlated to the proportion of collagen fibers in the rat hearts after irradiation (r=0.48, P<0.05).

Conclusions: TGF-beta1 is involved not only in the onset but also in the development of radiation fibrosis. Inhibiting the peak expression of TGF-beta1 mRNA may reduce the radiation-induced damage to the heart.
View Article and Find Full Text PDF

Download full-text PDF

Source
January 2008

Surgical intervention for advanced valvular heart disease in 227 cases.

Chin Med J (Engl) 2005 Jun;118(12):989-94

Department of Cardiac Surgery, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China.

Background: Although the results of surgical treatment in cardiac valve disease continue to improve, the postoperative mortality rate and the rate of complications in patients with advanced valvular heart disease (AVHD) are still very high. We did this retrospective study to summarize the surgical experience of heart valve replacement for patients with AVHD and discuss effective ways to improve the surgical outcome.

Methods: From January 1994 to October 2003, surgical procedures of heart valve replacement were performed on 227 (136 men and 91 women) patients with AVHD in our Department of Cardiothoracic Surgery. The clinical data of all patients were collected and analysed. Patients' age ranged from 10 years to 77 years. In preoperative cardiac function grading, 157 cases were NYHA III and 70 cases NYHA IV. Fifty-one patients had had cardiac operations. The ultrasonic cardiac graphs showed that 145 patients suffered from moderate or severe pulmonary hypertension and 73 had combined giant left ventricle. Mitral valve replacement was performed in 32 cases, aortic valve replacement in 90, tricuspid valve replacement in 1, combined mitral and aortic replacement in 103 and combined mitral and tricuspid replacement in 1. Nineteen patients also received surgical corrections for other minor abnormalities during the operations. A logistic model was established to evaluate the influence of perioperative factors on the mortality rate.

Results: The operative mortality rate was 13.2% (30/227). The main causes of death included multiple organ dysfunction syndrome (MODS), low cardiac output syndrome and ventricular fibrillation. From the results of the binary noncounterpart multivariate logistic regression, the following statistically significant factors were found to influence the operative mortality rate: redo operation, age >/= 55 years, preoperative NYHA cardiac function grading, extracorporeal circulation time >/= 120 minutes and postoperative usage of GIK (glucose, insulin and potassium) solution. All factors were risk ones except postoperative application of GIK. The Hosmer-Lemeshow goodness of fit coefficient of this model was 0.976.

Conclusions: The risk factors associated with postoperative mortality rate in the patients with AVHD were redo operation, age >/= 55 years, preoperative NYHA cardiac function grading and extracorporeal circulation time >/= 120 minutes. Postoperative usage of GIK acted as a kind of metabolic therapy and will improve the recovery for patients with AVHD. Active perioperative management and care will play a very important role in reducing the operative risk and improving the short term outcome of surgical treatment for the patients with AVHD.
View Article and Find Full Text PDF

Download full-text PDF

Source
June 2005
-->