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1.
ESMO Open ; 9(4): 102942, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38503143

RESUMO

BACKGROUND: Optimizing immune checkpoint inhibitor (ICI) therapy may require identification of co-targetable checkpoint pathways via immune profiling. Herein, we analyzed the transcriptomic expression and clinical correlates of V-domain immunoglobulin suppressor of T-cell activation (VISTA), a promising targetable checkpoint. PATIENTS AND METHODS: RNA sequencing was carried out on 514 tissues reflecting diverse advanced/metastatic cancers. Expression of eight immune checkpoint markers [lymphocyte-activation gene 3 (LAG-3), tumor necrosis factor receptor superfamily 14 (TNFRSF14), programmed cell death protein 1 (PD-1), programmed death-ligand 1 (PD-L1), programmed death-ligand 2 (PD-L2), B- and T-lymphocyte attenuator (BTLA), T-cell immunoglobulin and mucin domain-containing protein 3 (TIM-3), cytotoxic T-lymphocyte antigen 4 (CTLA-4)], in addition to VISTA, was analyzed, along with clinical outcomes. RESULTS: High VISTA RNA expression was observed in 32% of tumors (66/514) and was the most common highly expressed checkpoint among the nine assessed. High VISTA expression was independently correlated with high BTLA, TIM-3, and TNFRSF14, and with a diagnosis of pancreatic, small intestine, and stomach cancer. VISTA transcript levels did not correlate with overall survival (OS) from metastatic/advanced disease in the pan-cancer cohort or with immunotherapy outcome (progression-free survival and OS from the start of ICI) in 217 ICI-treated patients. However, in ICI-treated pancreatic cancer patients (n = 16), median OS was significantly shorter (from immunotherapy initiation) for the high- versus not-high-VISTA groups (0.28 versus 1.21 years) (P = 0.047); in contrast, VISTA levels were not correlated with OS in 36 pancreatic cancer patients who did not receive ICI. CONCLUSION: High VISTA expression correlates with high BTLA, TIM-3, and TNFRSF14 checkpoint-related molecules and with poorer post-immunotherapy survival in pancreatic cancer, consistent with prior literature indicating that VISTA is prominently expressed on CD68+ macrophages in pancreatic cancers and requiring validation in larger prospective studies. Immunomic analysis may be important for individualized precision immunotherapy.


Assuntos
Antígenos B7 , Neoplasias , Humanos , Neoplasias/imunologia , Antígenos B7/metabolismo , Masculino , Feminino , Inibidores de Checkpoint Imunológico/uso terapêutico , Inibidores de Checkpoint Imunológico/farmacologia , Pessoa de Meia-Idade , Biomarcadores Tumorais/metabolismo , Proteínas de Checkpoint Imunológico/metabolismo , Idoso
3.
Ann Oncol ; 32(12): 1626-1636, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34606929

RESUMO

BACKGROUND: Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy; however, there is empirical variability across panel assays and factors contributing to this variability have not been comprehensively investigated. Identifying sources of variability can help facilitate comparability across different panel assays, which may aid in broader adoption of panel assays and development of clinical applications. MATERIALS AND METHODS: Twenty-nine tumor samples and 10 human-derived cell lines were processed and distributed to 16 laboratories; each used their own bioinformatics pipelines to calculate TMB and compare to whole exome results. Additionally, theoretical positive percent agreement (PPA) and negative percent agreement (NPA) of TMB were estimated. The impact of filtering pathogenic and germline variants on TMB estimates was assessed. Calibration curves specific to each panel assay were developed to facilitate translation of panel TMB values to whole exome sequencing (WES) TMB values. RESULTS: Panel sizes >667 Kb are necessary to maintain adequate PPA and NPA for calling TMB high versus TMB low across the range of cut-offs used in practice. Failure to filter out pathogenic variants when estimating panel TMB resulted in overestimating TMB relative to WES for all assays. Filtering out potential germline variants at >0% population minor allele frequency resulted in the strongest correlation to WES TMB. Application of a calibration approach derived from The Cancer Genome Atlas data, tailored to each panel assay, reduced the spread of panel TMB values around the WES TMB as reflected in lower root mean squared error (RMSE) for 26/29 (90%) of the clinical samples. CONCLUSIONS: Estimation of TMB varies across different panels, with panel size, gene content, and bioinformatics pipelines contributing to empirical variability. Statistical calibration can achieve more consistent results across panels and allows for comparison of TMB values across various panel assays. To promote reproducibility and comparability across assays, a software tool was developed and made publicly available.


Assuntos
Mutação , Neoplasias , Biomarcadores Tumorais , Humanos , Neoplasias/diagnóstico , Neoplasias/genética , Reprodutibilidade dos Testes , Carga Tumoral
4.
Eur Radiol ; 28(3): 963-971, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28986631

RESUMO

OBJECTIVE: To compare the diagnostic accuracy of conventional 3T MRI against 1.5T MR arthrography (MRA) in patients with clinical femoroacetabular impingement (FAI). METHODS: Sixty-eight consecutive patients with clinical FAI underwent both 1.5T MRA and 3T MRI. Imaging was prospectively analysed by two musculoskeletal radiologists, blinded to patient outcomes and scored for internal derangement including labral and cartilage abnormality. Interobserver variation was assessed by kappa analysis. Thirty-nine patients subsequently underwent hip arthroscopy and surgical results and radiology findings were analysed. RESULTS: Both readers had higher sensitivities for detecting labral tears with 3T MRI compared to 1.5T MRA (not statistically significant p=0.07). For acetabular cartilage defect both readers had higher statistically significant sensitivities using 3T MRI compared to 1.5T MRA (p=0.02). Both readers had a slightly higher sensitivity for detecting delamination with 1.5T MRA compared to 3T MRI, but these differences were not statistically significant (p=0.66). Interobserver agreement was substantial to perfect agreement for all parameters except the identification of delamination (3T MRI showed moderate agreement and 1.5T MRA substantial agreement). CONCLUSION: Conventional 3T MRI may be at least equivalent to 1.5T MRA in detecting acetabular labrum and possibly superior to 1.5T MRA in detecting cartilage defects in patients with suspected FAI. KEY POINTS: • Conventional 3T MRI is equivalent to 1.5T MRA for diagnosing labral tears. • Conventional 3T MRI is superior to 1.5T MRA for diagnosing acetabular cartilage defect. • Conventional 3T MRI is equivalent to 1.5T MRA for diagnosing cartilage delamination. • Symptom severity score was significantly higher (p<0.05) in group proceeding to surgery.


Assuntos
Artrografia/métodos , Doenças das Cartilagens/patologia , Cartilagem Articular/diagnóstico por imagem , Impacto Femoroacetabular/diagnóstico por imagem , Articulação do Quadril/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos , Acetábulo/diagnóstico por imagem , Adulto , Doenças das Cartilagens/complicações , Feminino , Impacto Femoroacetabular/etiologia , Humanos , Masculino , Reprodutibilidade dos Testes
5.
Clin Genet ; 89(2): E1-3, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26235277

RESUMO

Next-generation sequencing has accelerated the identification of disease genes in many rare genetic disorders including early-onset epileptic encephalopathies (EOEEs). While many of these disorders are caused by neuronal channelopathies, the role of synaptic and related neuronal proteins are increasingly being described. Here, we report a 6-year-old girl with unexplained EOEE characterized by multifocal seizures and profound global developmental delay. Recessive inheritance was considered due to parental consanguinity and Irish Traveller descent. Exome sequencing was performed. Variant prioritization identified a homozygous nonsense variant in the N-ethylmaleimide-sensitive factor attachment protein, beta (NAPB) gene resulting in a premature stop codon and 46% loss of the protein. NAPB plays a role in soluble N-ethylmaleimide-sensitive fusion attachment protein receptor (SNARE)-complex dissociation and recycling (synaptic vesicle docking). Knockout mouse models of the murine ortholog Napb have been previously reported. These mice develop recurrent post-natal epileptic seizures in the absence of structural brain changes. The identification of a disease-causing variant in NAPB further recognizes the importance of the SNARE complex in the development of epilepsy and suggests that this gene should be considered in patients with unexplained EOEE.


Assuntos
Epilepsia/epidemiologia , Epilepsia/genética , Proteínas SNARE/metabolismo , Idade de Início , Criança , Exoma/genética , Feminino , Humanos
6.
Artigo em Inglês | MEDLINE | ID: mdl-26066124

RESUMO

The nonextensive entropic measure proposed by Tsallis [C. Tsallis, J. Stat. Phys. 52, 479 (1988)] introduces a parameter, q, which is not defined but rather must be determined. The value of q is typically determined from a piece of data and then fixed over the range of interest. On the other hand, from a phenomenological viewpoint, there are instances in which q cannot be treated as a constant. We present two distinct approaches for determining q depending on the form of the equations of constraint for the particular system. In the first case the equations of constraint for the operator Ô can be written as Tr(F(q)Ô)=C, where C may be an explicit function of the distribution function F. We show that in this case one can solve an equivalent maxent problem which yields q as a function of the corresponding Lagrange multiplier. As an illustration the exact solution of the static generalized Fokker-Planck equation (GFPE) is obtained from maxent with the Tsallis enropy. As in the case where C is a constant, if q is treated as a variable within the maxent framework the entropic measure is maximized trivially for all values of q. Therefore q must be determined from existing data. In the second case an additional equation of constraint exists which cannot be brought into the above form. In this case the additional equation of constraint may be used to determine the fixed value of q.

7.
Case Rep Genet ; 2013: 764152, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23424688

RESUMO

We report a case of Albright hereditary osteodystrophy (AHO) in a three-year-old girl with a microduplication at 17q11.2. The child developed obesity within the first 6 months of life. A diagnosis of Albright was made at age 2 years when biochemical evidence of parathyroid resistance was found. No mutations were identified in guanine nucleotide-binding protein G (s) subunit alpha (GNAS1). Subsequent investigations revealed methylation disturbance at GNAS1A, neuroendocrine secretory protein antisense (NESPAS) and neuroendocrine secretory protein 55 (NESP55) confirming a diagnosis of pseudohypothyroidism type 1B. A deletion of NESP55 and uniparental disomy chromosome 20 were excluded which suggested that the features of AHO arose through a purely epigenetic mechanism. Further investigation revealed a de novo microduplication at 17q11.2 encompassing the neurofibromatosis type 1 (NF1) gene. The combination of two rare de novo events in the same child raises the possibility that duplication of a gene within the 17q11.2 region may have triggered abnormal methylation in the GNAS cluster region on chromosome 20.

8.
Anim Genet ; 44(4): 408-12, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23278111

RESUMO

Equine osteochondrosis is a developmental joint disease that is a significant source of morbidity affecting multiple breeds of horse. The genetic variants underlying osteochondrosis susceptibility have not been established. Here, we describe the results of a genome-wide association study of osteochondrosis using 90 cases and 111 controls from a population of Dutch Warmblood horses. We report putative associations between osteochondrosis and loci on chromosome 3 (BIEC2-808543; P = 5.03 × 10(-7) ) and chromosome 10 (BIEC2-121323; P = 2.62 × 10(-7) ).


Assuntos
Cromossomos de Mamíferos/genética , Estudo de Associação Genômica Ampla/veterinária , Doenças dos Cavalos/genética , Artropatias/veterinária , Osteocondrose/veterinária , Animais , Cruzamento , Mapeamento Cromossômico/veterinária , Feminino , Loci Gênicos/genética , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla/métodos , Genótipo , Haplótipos , Doenças dos Cavalos/diagnóstico por imagem , Cavalos , Artropatias/diagnóstico por imagem , Artropatias/genética , Masculino , Osteocondrose/diagnóstico por imagem , Osteocondrose/genética , Fenótipo , Polimorfismo de Nucleotídeo Único , Radiografia
9.
Am J Primatol ; 73(3): 291-303, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21274900

RESUMO

The ranges of small kinda (Papio kindae) and much larger grayfooted chacma (P. ursinus griseipes) baboons adjoin in the Kafue National Park, Zambia. In a visual survey of baboons at 48 sites in the Kafue River drainage we found that, contrary to previous reports, groups at the species interface near the town of Ngoma are phenotypically diverse and presumably formed by multigenerational hybridization. Mitochondrial and/or Y-chromosome genetic markers from fecal samples (N=164) collected at 29 sites support this conclusion. Groups with phenotypic signs of a history of hybridization also had taxon-specific mitochondria and Y-haplotypes from both parental species. Although the distribution of mitochondrial haplotypes largely mirrored that of external phenotypes, a significant proportion of male specimens from grayfoot as well as hybrid groups carried kinda Y-chromosomes, and kinda Y-chromosomes were involved in all observed cases of mitochondrial/Y-chromosome discordance. These observations are consistent with, though they do not prove, a population history in which the range of chacmas and the hybrid zone have advanced at the expense of the kinda range. They also suggest that, unexpectedly, kinda male×chacma female matings are much more common than the reciprocal cross in the ancestry of hybrids. We suggest that distinctive male kinda behavior and the "juvenile" appearance of kinda baboons of both sexes, perhaps combined with obstetric difficulties of a small kinda female carrying the large offspring of a chacma male, may account for this bias.


Assuntos
Hibridização Genética , Papio/genética , Animais , Animais Selvagens/anatomia & histologia , Animais Selvagens/genética , DNA Mitocondrial/genética , DNA Mitocondrial/isolamento & purificação , Feminino , Genes Ligados ao Cromossomo Y/genética , Marcadores Genéticos , Variação Genética , Haplótipos , Masculino , Papio/anatomia & histologia , Papio ursinus/anatomia & histologia , Papio ursinus/genética , Fenótipo , Comportamento Sexual Animal , Zâmbia
11.
Anim Genet ; 41 Suppl 2: 2-7, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21070269

RESUMO

The recent completion of the horse genome and commercial availability of an equine SNP genotyping array has facilitated the mapping of disease genes. We report putative localization of the gene responsible for dwarfism, a trait in Friesian horses that is thought to have a recessive mode of inheritance, to a 2-MB region of chromosome 14 using just 10 affected animals and 10 controls. We successfully genotyped 34,429 SNPs that were tested for association with dwarfism using chi-square tests. The most significant SNP in our study, BIEC2-239376 (P(2df)=4.54 × 10(-5), P(rec)=7.74 × 10(-6)), is located close to a gene implicated in human dwarfism. Fine-mapping and resequencing analyses did not aid in further localization of the causative variant, and replication of our findings in independent sample sets will be necessary to confirm these results.


Assuntos
Nanismo/veterinária , Estudo de Associação Genômica Ampla , Doenças dos Cavalos/genética , Polimorfismo de Nucleotídeo Único , Animais , Nanismo/genética , Cavalos
12.
Genes Brain Behav ; 9(7): 841-8, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20662941

RESUMO

The brain-derived neurotrophic factor (BDNF), a neurotrophin fundamental for brain development and function, has previously been implicated in autism. In this study, the levels of BDNF in platelet-rich plasma were compared between autistic and control children, and the role of two genetic factors that might regulate this neurotrophin and contribute to autism etiology, BDNF and NTRK2, was examined. We found that BDNF levels in autistic children (n = 146) were significantly higher (t = 6.82; P < 0.0001) than in control children (n = 50) and were positively correlated with platelet serotonin distribution (r = 0.22; P = 0.004). Heritability of BDNF was estimated at 30% and therefore candidate genes BDNF and NTRK2 were tested for association with BDNF level distribution in this sample, and with autism in 469 trio families. Genetic association analysis provided no evidence for BDNF or NTRK2 as major determinants of the abnormally increased BDNF levels in autistic children. A significant association with autism was uncovered for six single nucleotide polymorphisms (SNPs) [0.004 (Z((1df)) = 2.85) < P < 0.039 (Z((1df)) = 2.06)] and multiple haplotypes [5 × 10(-4) (χ((3df)) = 17.77) < P < 0.042 (χ((9df)) = 17.450)] in the NTRK2 gene. These results do not withstand correction for multiple comparisons, however, reflect a trend toward association that supports a role of NTRK2 as a susceptibility factor for the disorder. Genetic variation in the BDNF gene had no impact on autism risk. By substantiating the previously observed increase in BDNF levels in autistic children in a larger patient set, and suggesting a genetic association between NTRK2 and autism, this study integrates evidence from multiple levels supporting the hypothesis that alterations in BDNF/tyrosine kinase B (TrkB) signaling contribute to an increased vulnerability to autism.


Assuntos
Transtorno Autístico/genética , Fator Neurotrófico Derivado do Encéfalo/genética , Receptor trkB/genética , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Adolescente , Plaquetas/metabolismo , Fator Neurotrófico Derivado do Encéfalo/biossíntese , Criança , Pré-Escolar , Feminino , Genótipo , Haplótipos , Humanos , Masculino , Receptor trkB/biossíntese
13.
Clin Orthop Relat Res ; 467(11): 3029-31, 2009 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-19459020

RESUMO

The Rhodococcus species rarely cause musculoskeletal infections, with only two cases reported in the literature. We report the case of a 53-year-old woman who had an infection develop after first metatarsophalangeal joint fusion. A year after surgery, she continued to have pain and swelling with nonunion. She underwent revision of the arthrodesis and tissue samples from surgery revealed Rhodococcus erythropolis. The patient's symptoms improved with oral antibiotics. One year after the revision surgery, the fusion had united. We believe this is the first report of a case of a musculoskeletal infection caused by Rhodococcus erythropolis.


Assuntos
Infecções por Actinomycetales/terapia , Artrodese/efeitos adversos , Articulação Metatarsofalângica/cirurgia , Osteomielite/microbiologia , Rhodococcus/isolamento & purificação , Dedos do Pé , Infecções por Actinomycetales/diagnóstico , Antibacterianos/uso terapêutico , Artrodese/métodos , Terapia Combinada , Feminino , Seguimentos , Hallux Rigidus , Humanos , Articulação Metatarsofalângica/diagnóstico por imagem , Articulação Metatarsofalângica/fisiopatologia , Pessoa de Meia-Idade , Osteomielite/diagnóstico por imagem , Osteomielite/etiologia , Osteomielite/terapia , Complicações Pós-Operatórias/microbiologia , Complicações Pós-Operatórias/terapia , Radiografia , Doenças Raras , Reoperação , Medição de Risco , Índice de Gravidade de Doença , Resultado do Tratamento
14.
Allergy Asthma Proc ; 28(5): 592-9, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-18034980

RESUMO

Rapid relief of symptoms should be one of the primary goals of treatment for allergic rhinitis (AR). The onset and duration of action of olopatadine hydrochloride nasal spray, 665 mcg (OLO; Patanese), for seasonal AR (SAR) was evaluated in this study. This study was performed to determine the onset and duration of action of OLO compared with placebo spray, with mometasone furoate monohydrate, 50 mcg (MM; Nasonex), as a reference standard. This was a single center, single-dose, randomized, double-blinded parallel-group environmental exposure chamber study. Patients were primed at two 2-hour priming visits. Eligible patients were randomized to OLO, placebo spray, or MM, 2 sprays/nostril. Allergy symptoms (sneezing, runny, itchy, and stuffy nose) were rated by patients at 16 time points during 12 hours after dosing and patient satisfaction was assessed at 4 and 12 hours postdose. Safety was assessed by a review of adverse events, cardiovascular and nasal examination parameters. Four hundred twenty-five adult patients were randomized. OLO was superior to placebo spray in reducing total nasal symptoms (TNSS) within 30 minutes after dosing and maintained superiority for at least 12 hours (p < 0.05). The onset of MM was not observed until 150 minutes postdose and was smaller in magnitude compared with OLO. OLO was superior to both placebo spray (p < 0.0001) and MM (p < 0.05) in patient satisfaction. Treatment was well-tolerated with no safety concerns. OLO is superior to placebo spray and MM in reducing allergy symptoms; OLO has a rapid onset of action and a duration of effect of at least 12 hours.


Assuntos
Antialérgicos , Dibenzoxepinas , Pregnadienodiois , Rinite Alérgica Sazonal/tratamento farmacológico , Administração Intranasal , Adolescente , Adulto , Idoso , Antialérgicos/administração & dosagem , Antialérgicos/efeitos adversos , Antialérgicos/uso terapêutico , Câmaras de Exposição Atmosférica , Dibenzoxepinas/administração & dosagem , Dibenzoxepinas/efeitos adversos , Dibenzoxepinas/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Furoato de Mometasona , Cloridrato de Olopatadina , Pregnadienodiois/administração & dosagem , Pregnadienodiois/efeitos adversos , Pregnadienodiois/uso terapêutico , Fatores de Tempo , Resultado do Tratamento
15.
Exp Mol Pathol ; 82(2): 121-9, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17320864

RESUMO

Cervical cancer is the second most common cancer in women worldwide with 80% of cases arising in the developing world. The mortality associated with cervical cancer can be reduced if this disease is detected at the early stages of development or at the pre-malignant state (cervical intraepithelial neoplasia, CIN). The aim of this study was to investigate the potential of Raman spectroscopy as a diagnostic tool to detect biochemical changes accompanying cervical cancer progression. Raman spectra were acquired from proteins, nucleic acids, lipids and carbohydrates in order to gain an insight into the biochemical composition of cells and tissues. Spectra were also obtained from histological samples of normal, CIN and invasive carcinoma tissue from 40 patients. Multivariate analysis of the spectra was carried out to develop a classification model to discriminate normal from abnormal tissue. The results show that Raman spectroscopy displays a high sensitivity to biochemical changes in tissue during disease progression resulting in an exceptional prediction accuracy when discriminating between normal cervical tissue, invasive carcinoma and cervical intraepithelial neoplasia (CIN). Raman spectroscopy shows enormous clinical potential as a rapid non-invasive diagnostic tool for cervical and other cancers.


Assuntos
Displasia do Colo do Útero/química , Neoplasias do Colo do Útero/química , Aminoácidos/análise , Carboidratos/análise , Feminino , Humanos , Lipídeos/análise , Ácidos Nucleicos/análise , Peptídeos/análise , Análise Espectral Raman , Neoplasias do Colo do Útero/diagnóstico , Neoplasias do Colo do Útero/patologia , Displasia do Colo do Útero/diagnóstico , Displasia do Colo do Útero/patologia
16.
Tree Physiol ; 27(2): 251-60, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17241967

RESUMO

Wood density, a gross measure of wood mass relative to wood volume, is important in our understanding of stem volume growth, carbon sequestration and leaf water supply. Disproportionate changes in the ratio of wood mass to volume may occur at the level of the whole stem or the individual cell. In general, there is a positive relationship between temperature and wood density of eucalypts, although this relationship has broken down in recent years with wood density decreasing as global temperatures have risen. To determine the anatomical causes of the effects of temperature on wood density, Eucalyptus grandis W. Hill ex Maiden seedlings were grown in controlled-environment cabinets at constant temperatures from 10 to 35 degrees C. The 20% increase in wood density of E. grandis seedlings grown at the higher temperatures was variously related to a 40% reduction in lumen area of xylem vessels, a 10% reduction in the lumen area of fiber cells and a 10% increase in fiber cell wall thickness. The changes in cell wall characteristics could be considered analogous to changes in carbon supply. Lumen area of fiber cells declined because of reduced fiber cell expansion and increased fiber cell wall thickening. Fiber cell wall thickness was positively related to canopy CO2 assimilation rate (Ac), which increased 26-fold because of a 24-fold increase in leaf area and a doubling in leaf CO2 assimilation rate from minima at 10 and 35 degrees C to maxima at 25 and 30 degrees C. Increased Ac increased seedling volume, biomass and wood density; but increased wood density was also related to a shift in partitioning of seedling biomass from roots to stems as temperature increased.


Assuntos
Eucalyptus/crescimento & desenvolvimento , Fotossíntese/fisiologia , Plântula/crescimento & desenvolvimento , Temperatura , Madeira/crescimento & desenvolvimento , Biomassa , Eucalyptus/anatomia & histologia , Eucalyptus/fisiologia , Plântula/anatomia & histologia , Plântula/fisiologia , Madeira/anatomia & histologia , Xilema/crescimento & desenvolvimento
17.
Tree Physiol ; 26(1): 35-42, 2006 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16203712

RESUMO

Wood density influences both the physiological function and economic value of tree stems. We examined the relationship between phosphorus (P) supply and stem wood density of Eucalyptus grandis Hill ex Maiden seedlings grown with varying soil P additions and determined how changes in wood anatomy and biomass partitioning affect the relationship. Plant height, stem diameter and total biomass increased by 400-500% with increasing P supply. Stem wood density decreased sharply from 520 to 380 kg m(-3) as P supply increased to 70 mg P kg(soil) (-1). Further increases in P supply to 1000 mg P kg(soil) (-1) had no effect on wood density. The increase in wood density at low soil P supply arose principally from enhanced secondary wall thickening of stem fiber cells. Cell wall thickness increased from 3.6 to 4.5 microm as soil P supply decreased. Because fiber cell diameter was independent of soil P (12 microm +/- 0.3), the proportion of the stem occupied by cell wall material increased as P supply declined. The enhanced secondary wall thickening of stem fiber cells at low P supply was not associated with changes in whole-plant biomass partitioning. Instead, low P supply appeared to alter biomass partitioning within the stem in favor of secondary wall thickening. Thus, increased wood density in E. grandis seedlings grown at low P soil supply was associated with inhibited stem cambial activity, resulting in an increased proportion of photoassimilates available for secondary wall thickening of fiber cells.


Assuntos
Eucalyptus/anatomia & histologia , Fósforo/provisão & distribuição , Caules de Planta/anatomia & histologia , Plântula/anatomia & histologia , Madeira/anatomia & histologia , Eucalyptus/crescimento & desenvolvimento , Solo/análise , Madeira/citologia
19.
Br J Cancer ; 93(6): 699-708, 2005 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-16222315

RESUMO

High-resolution array comparative genomic hybridisation (aCGH) analysis of DNA copy number aberrations (CNAs) was performed on breast carcinomas in premenopausal women from Western New York (WNY) and from Gomel, Belarus, an area exposed to fallout from the 1986 Chernobyl nuclear accident. Genomic DNA was isolated from 47 frozen tumour specimens from 42 patients and hybridised to arrays spotted with more than 3000 BAC clones. In all, 20 samples were from WNY and 27 were from Belarus. In total, 34 samples were primary tumours and 13 were lymph node metastases, including five matched pairs from Gomel. The average number of total CNAs per sample was 76 (range 35-134). We identified 152 CNAs (92 gains and 60 losses) occurring in more than 10% of the samples. The most common amplifications included gains at 8q13.2 (49%), at 1p21.1 (36%), and at 8q24.21 (36%). The most common deletions were at 1p36.22 (26%), at 17p13.2 (26%), and at 8p23.3 (23%). Belarussian tumours had more amplifications and fewer deletions than WNY breast cancers. HER2/neu negativity and younger age were also associated with a higher number of gains and fewer losses. In the five paired samples, we observed more discordant than concordant DNA changes. Unsupervised hierarchical cluster analysis revealed two distinct groups of tumours: one comprised predominantly of Belarussian carcinomas and the other largely consisting of WNY cases. In total, 50 CNAs occurred significantly more commonly in one cohort vs the other, and these included some candidate signature amplifications in the breast cancers in women exposed to significant radiation. In conclusion, our high-density aCGH study has revealed a large number of genetic aberrations in individual premenopausal breast cancer specimens, some of which had not been reported before. We identified a distinct CNA profile for carcinomas from a nuclear fallout area, suggesting a possible molecular fingerprint of radiation-associated breast cancer.


Assuntos
Neoplasias da Mama/genética , Acidente Nuclear de Chernobyl , Aberrações Cromossômicas , Neoplasias Induzidas por Radiação/genética , Pré-Menopausa , Adulto , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/genética , Carcinoma Ductal de Mama/patologia , Carcinoma Lobular/genética , Carcinoma Lobular/patologia , DNA de Neoplasias/análise , Feminino , Dosagem de Genes , Humanos , Análise em Microsséries , Pessoa de Meia-Idade , New York , Hibridização de Ácido Nucleico , Receptor ErbB-2/metabolismo , República de Belarus
20.
Br J Cancer ; 90(4): 860-5, 2004 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-14970865

RESUMO

Constitutional chromosome deletions and duplications frequently predispose to the development of a wide variety of cancers. We have developed a microarray of 6000 bacterial artificial chromosomes for array-based comparative genomic hybridisation, which provides an average resolution of 750 kb across the human genome. Using these arrays, subtle gains and losses of chromosome regions can be detected in constitutional cells, following a single overnight hybridisation. In this report, we demonstrate the efficiency of this procedure in identifying constitutional deletions and duplications associated with predisposition to retinoblastoma, Wilms tumour and Beckwith-Wiedemann syndrome.


Assuntos
Deleção Cromossômica , Cromossomos Artificiais Bacterianos , Predisposição Genética para Doença , Bactérias/genética , Síndrome de Beckwith-Wiedemann/genética , Humanos , Neoplasias Renais/genética , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , Retinoblastoma/genética , Tumor de Wilms/genética
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