Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 22
Filtrar
1.
Fertil Steril ; 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38964587

RESUMO

OBJECTIVE: To study the association between antimüllerian hormone (AMH) levels and time of pregnancy. Although it has been hypothesized that serum AMH levels may indicate the chance of conception, findings have been mixed. Given that any association is expected to be modest, and it is possible that previous studies have been underpowered, we investigated this relationship in the largest prospective cohort to date. DESIGN: Prospective time-to-pregnancy cohort study. SETTING: Community. PATIENT(S): A total of 3,150 US women who had been trying to conceive for <3 months and had purchased a Modern Fertility hormone test. INTERVENTION(S): We developed a discrete time-to-event model using a binomial complementary log-log error structure within a generalized additive modeling framework, adjusting for confounding factors such as age, body mass index, parity, smoking status, polycystic ovary syndrome, and others. Sensitivity analyses were performed in women with regular menstrual cycles (21-35 days), who did not report using fertility treatments, using alternate AMH level categories (<0.7, 0.7-8.5, >8.5 ng/mL), and AMH levels as a continuous measure. MAIN OUTCOME MEASURE(S): Primary outcomes included cumulative conception probability within 12 cycles and relative fecundability per menstrual cycle. Conception was defined by a self-reported positive pregnancy test. RESULT(S): Participants contributed 7.21 ± 5.32 cycles, with 1,325 (42.1%) achieving a pregnancy. Women with low AMH levels (<1 ng/mL, n = 427) had a lower chance of natural conception (adjusted hazard ratio [adjHR], 0.77; 95% confidence interval [CI], 0.64-0.94) compared with women with normal AMH levels (1-5.5 ng/mL). There was no difference between high (5.5+ ng/mL) and normal AMH level categories (adjHR, 1.11; 95% CI, 0.94-1.31). The inclusion of AMH improved the model (net reclassification index 0.10 [0.06-0.14]). The instantaneous probability of conception was highest in cycle four across all AMH categories: the probability of natural conception was 11.2% (95% CI, 9.0-14.0) for low AMH levels, 14.3% (95% CI, 12.3-16.5) for normal AMH levels, and 15.7% (95% CI, 12.9-19.0) for high AMH levels. In the regular cycles sensitivity analysis (n = 1,791), the low AMH group had a lower chance of conception (adjHR, 0.77; 95% CI, 0.61-0.97) in the low AMH group compared with normal AMH, and similarly in the continuous model (adjHR, 0.90; 95% CI, 0.85-0.95). CONCLUSION(S): Low AMH levels (<1 ng/mL) are independently associated with a modest but significant reduction in the chance of conception.

2.
CHEST Crit Care ; 2(1): 100050, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38524255

RESUMO

Background: Sepsis is one of the most common reasons for ICU admission and a leading cause of mortality worldwide. More than one-half of survivors experience significant physical, psychological, or cognitive impairments, often termed post-intensive care syndrome (PICS). Sepsis is recognized increasingly as being associated with a risk of adverse cardiovascular events that is comparable with other major cardiovascular risk factors. It is plausible that sepsis survivors may be at risk of unidentified cardiovascular disease, and this may play a role in functional impairments seen after ICU discharge. Research Question: What is the prevalence of myocardial dysfunction after an ICU admission with sepsis and to what extent might it be associated with physical impairments in PICS? Study Design and Methods: Characterisation of Cardiovascular Function in ICU Survivors of Sepsis (CONDUCT-ICU) is a prospective, multicenter, pilot study characterizing cardiovascular function and functional impairments in survivors of sepsis taking place in the west of Scotland. Survivors of sepsis will be recruited at ICU discharge and followed up 6 to 10 weeks after hospital discharge. Biomarkers of myocardial injury or dysfunction (high sensitivity troponin and N-terminal pro B-type natriuretic peptide) and systemic inflammation (C-reactive protein, IL-1ß, IL-6, IL-10, and tumor necrosis factor alpha) will be measured in 69 patients at recruitment and at follow-up. In addition, a cardiovascular magnetic resonance substudy will be performed at follow-up in 35 patients. We will explore associations between cardiovascular magenetic resonance indexes of cardiac function, biomarkers of cardiac dysfunction and inflammation, and patient-reported outcome measures. Interpretation: CONDUCT-ICU will provide data regarding the cause and prevalence of cardiac dysfunction in survivors of sepsis and will explore associations with functional impairment. It will provide feasibility data and operational learning for larger studies investigating mechanisms of functional impairment after ICU admission and the association between sepsis and adverse cardiovascular events. Trial Registry: ClinicalTrials.gov; No.: NCT05633290; URL: www.clinicaltrials.gov.

3.
Eur J Hosp Pharm ; 2023 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-36707237

RESUMO

OBJECTIVE: Elective surgery suffered significant loss of capacity during the COVID-19 pandemic. To address this, hip and knee arthroplasties are being conducted as day case procedures. Pre-admission pharmacist consultations were introduced (the intervention) for these patients. This consultation aimed to address perioperative medicines issues, promote patient empowerment, improve prescribing quality and contribute to reduction in length of stay (LoS). METHODS: All patients listed for a total/unicompartmental knee replacement (TKR/UKR) or total hip replacement (THR) at an ambulatory care hospital were identified by a pharmacist prescriber 1-2 weeks before the operation. Pharmacist consultations were conducted remotely with discharge prescriptions written electronically and dispensed before admission. Prescribing data were collected for both pre-intervention (n=80) and post-intervention (n=129) groups along with all interventions undertaken during consultations. Staff opinion was sought via online questionnaire and patient opinion was gathered via post-discharge telephone calls. RESULTS: A total of 115 interventions took place during 129 patient consultations and >75% of interventions were of a significance expected to improve patient care. Prescribing standards were improved in the intervention group compared with patients whose arthroplasty was before the introduction of this service. The pharmacy service would have produced a different prescription in 38.8% of the pre-intervention group. Staff and patient feedback was extremely positive and all patients with previous surgical experience in the health board reported an improved experience. There was a statistically significant reduction in post-discharge healthcare encounters (such as general practitioner (GP) visits) in the intervention group. CONCLUSION: This novel remote preoperative pharmacist consultation improved prescribing standards, enhanced the patient's surgical experience and reduced the burden on post-discharge healthcare systems.

4.
Trauma Surg Acute Care Open ; 6(1): e000810, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34722931

RESUMO

OBJECTIVES: Pruritus is a common and often distressing complication after a burn injury. The purpose of this review is to explore the efficacy of drugs classically used to treat neuropathic pain in the management of pruritus after burn injury. METHODS: A systematic literature search of medical databases was conducted to find studies investigating drugs listed in the National Institute for Health and Care Excellence (NICE) guideline (CG173, "neuropathic pain in adults") for the management of pruritus after burn injury in patients of any age. Controlled studies were stratified by the drug class studied and their risk of bias before conducting meta-analysis. A narrative review of case series or observational studies was presented. Severity of pruritus at any time point, with all quantitative and qualitative measures, was included. RESULTS: Fifteen studies were included in the final analysis, 10 investigated the use of gabapentinoids, 4 studied doxepin, and 1 local anesthetic agents. Meta-analysis of three randomized controlled trials (RCTs) demonstrated that the use of gabapentinoids was associated with an improvement in mean VAS (Visual Analog Scale) 0-10 scores of 2.96 (95% confidence interval (95% CI) 1.20 to 4.73, p<0.001) when compared with placebo or antihistamine. A meta-analysis of four RCTs investigating topical doxepin showed an improvement in mean VAS scores of 1.82 (95% CI 0.55 to 3.09, p<0.001). However, when excluding two studies found to be at high risk of bias, no such improvement was found (-0.32, 95% CI -1.64 to -0.99, p=0.83). CONCLUSION: This study suggests that gabapentinoids are beneficial in the management of burn-related pruritus. There is a lack of evidence to suggest that doxepin is an effective treatment. Topical local anesthetic agents may be safe and beneficial, but studies are scarce. LEVEL OF EVIDENCE: Systematic review, level II.

5.
J Surg Oncol ; 124(7): 1060-1069, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34350587

RESUMO

BACKGROUND AND OBJECTIVES: Gastrectomy for gastric cancer is associated with significant infective postoperative complications. C-reactive protein (CRP) is a useful biomarker in the early detection of infective complications following major abdominal surgery. This single-centre retrospective study aimed to determine the relationship between postoperative CRP levels and development of postoperative infective complications after gastrectomy. METHODS: Daily postoperative CRP levels were analyzed to determine a CRP threshold associated with infective complications. ROC curve analysis was used to determine which postoperative day (POD) gave the optimal cutoff. Multivariate analysis was performed to determine significant factors associated with complications. RESULTS: One hundred and forty-four patients were included. A total of 61 patients (42%) had at least one infective complication. A CRP level of 220 mg/L was associated with the highest AUC (0.765) with a sensitivity of 70% and specificity of 76% (positive predictive value, 67%; negative predictive value, 78%). More patients with a CRP > 220 mg/L on POD 3 developed infective complications (67% vs. 21%, p < 0.001). CONCLUSIONS: A CRP of more than 220 mg/L on POD 3 may be useful to alert clinicians to the increased risk of a postoperative infective complication or enable earlier safe discharge from critical care for those with a lower value.


Assuntos
Proteína C-Reativa/análise , Gastrectomia/efeitos adversos , Neoplasias Gástricas/cirurgia , Infecção da Ferida Cirúrgica/diagnóstico , Idoso , Biomarcadores/análise , Feminino , Humanos , Masculino , Valor Preditivo dos Testes , Estudos Retrospectivos , Sensibilidade e Especificidade
6.
Reg Anesth Pain Med ; 46(6): 482-489, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33832987

RESUMO

BACKGROUND: The fetus is vulnerable to maternal drug exposure. We determined associations of exposure to spinal, epidural, or general anesthesia on neonatal and childhood development outcomes during the first 1000 days of life. METHODS: Population-based study of all singleton, cesarean livebirths of 24+0 to 43+6 weeks gestation between January 2007 and December 2016 in Scotland, stratified by urgency with follow-up to age 2 years. Models were adjusted for: maternal age, weight, ethnicity, socioeconomic status, smoking, drug-use, induction, parity, previous cesarean or abortion, pre-eclampsia, gestation, birth weight, and sex. RESULTS: 140 866 mothers underwent cesarean section (41.2% (57,971/140,866) elective, 58.8% (82,895/140,866) emergency) with general anesthesia used in 3.2% (1877/57,971) elective and 9.8% (8158/82,895) of emergency cases. In elective cases, general anesthesia versus spinal was associated with: neonatal resuscitation (crude event rate 16.2% vs 1.9% (adjusted RR 8.20, 95% CI 7.20 to 9.33), Apgar <7 at 5 min (4.6% vs 0.4% (adjRR 11.44, 95% CI 8.88 to 14.75)), and neonatal admission (8.6% vs 4.9% (adjRR 1.65, 95% CI 1.40 to 1.94)). Associations were similar in emergencies; resuscitation (32.2% vs 12.3% (adjRR 2.40, 95% CI 2.30 to 2.50)), Apgar <7 (12.6% vs 2.8% (adjRR 3.87, 95% CI 3.56 to 4.20), and admission (31.6% vs 19.9% (adjRR 1.20, 95% CI 1.15 to 1.25). There was a weak association between general anesthesia in emergency cases and having ≥1 concern noted in developmental assessment at 2 years (21.0% vs 16.5% (adjRR 1.08, 95% CI 1.01 to 1.16)). CONCLUSIONS: General anesthesia for cesarean section, irrespective of urgency, is associated with neonatal resuscitation, low Apgar, and neonatal unit admission. Associations were strongest in non-urgent cases and at term. Further evaluation of long-term outcomes is warranted.


Assuntos
Cesárea , Ressuscitação , Anestesia Geral/efeitos adversos , Cesárea/efeitos adversos , Pré-Escolar , Estudos de Coortes , Feminino , Idade Gestacional , Humanos , Recém-Nascido , Gravidez , Estudos Retrospectivos
7.
Acta Neurochir Suppl ; 131: 115-117, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33839830

RESUMO

Intracranial pressure monitoring and brain tissue oxygen monitoring are commonly used in head injury for goal-directed therapies, but there may be more indications for its use. Moyamoya disease involves progressive stenosis of the arterial circulation and formation of collateral vessels that are at risk of hemorrhage. The risk of ischemic events during revascularization surgery and postoperatively is high. Impaired cerebral autoregulation may be one of the factors that are implicated. We present our experience with monitoring of cerebral oxygenation and autoregulation in the pathological hemisphere during the perioperative period in four patients with moyamoya disease.


Assuntos
Doença de Moyamoya , Encéfalo/diagnóstico por imagem , Encéfalo/cirurgia , Revascularização Cerebral , Circulação Cerebrovascular , Humanos , Pressão Intracraniana , Doença de Moyamoya/cirurgia , Oxigênio
8.
Acta Neurochir Suppl ; 131: 323-324, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33839867

RESUMO

Telemetric intracranial pressure (ICP) monitors are useful tools in the management of complex hydrocephalus and idiopathic intracranial hypertension (IIH). Clinicians may use them as a "snapshot" screening tool to assess shunt function or ICP. We compared "snapshot" telemetric ICP recordings with extended, in-patient periods of monitoring to determine whether this practice is safe and useful for clinical decision making.


Assuntos
Pressão Intracraniana , Humanos , Hidrocefalia , Monitorização Fisiológica , Pseudotumor Cerebral/diagnóstico , Telemetria
9.
Vet Anaesth Analg ; 46(5): 620-626, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31296379

RESUMO

OBJECTIVE: This pilot study aimed to evaluate the feasibility of transcranial bioimpedance (TCBI) measurement and variability of TCBI values in healthy conscious horses and to study effects of body position and time on TCBI in anaesthetized horses. STUDY DESIGN: Prospective, observational study. ANIMALS: A total of four research horses and 16 client-owned horses presented for surgery. METHODS: After establishing optimal electrode position using computed tomography scans of cadaver heads, TCBI [described using impedance at zero frequency, R0, (Ω)] was measured in four conscious, resting horses to investigate the feasibility and changes in TCBI over time (80 minutes). Data were compared using a paired t test. TCBI was then measured throughout anaesthesia (duration 92 ± 28 minutes) in 16 horses in dorsal and lateral recumbency. Data were analysed using a general linear model; gamma regression was chosen as a model of characteristic impedance [Zc; (Ω)] against time. Data are presented as mean ± standard deviation. RESULTS: No change in R0 was seen in conscious horses (age = 15.3 ± 7.3 years, body mass = 512 ± 38 kg) over 80 minutes. The technique was well tolerated and caused no apparent adverse effects. In 16 horses (age = 7.4 ± 4.7 years; body mass = 479 ± 134 kg) anaesthetized for 92 ± 28 minutes, Zc fell during anaesthesia, decreasing more in horses in lateral recumbency than in horses in dorsal recumbency (p = 0.008). There was no relationship between Zc and body mass or age. CONCLUSIONS AND CLINICAL RELEVANCE: TCBI is readily measured in horses. TCBI did not change with time in conscious horses, but decreased with time in anaesthetized horses; this change was greater in horses in lateral recumbency, indicating that TCBI changes in anaesthetized horses may be related to the effects of recumbency, general anaesthesia, surgery or a combination of these factors.


Assuntos
Anestesia Geral/veterinária , Encéfalo/fisiologia , Impedância Elétrica , Cavalos/fisiologia , Animais , Feminino , Cavalos/cirurgia , Período Intraoperatório , Masculino , Projetos Piloto , Estudos Prospectivos
10.
Plants (Basel) ; 8(7)2019 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-31336644

RESUMO

During analysis of kiwifruit derived from hybrids between the high vitamin C (ascorbic acid; AsA) species Actinidia eriantha and A. chinensis, we observed bimodal segregation of fruit AsA concentration suggesting major gene segregation. To test this hypothesis, we performed whole-genome sequencing on pools of hybrid genotypes with either high or low AsA fruit. Pool-GWAS (genome-wide association study) revealed a single Quantitative Trait Locus (QTL) spanning more than 5 Mbp on chromosome 26, which we denote as qAsA26.1. A co-dominant PCR marker was used to validate this association in four diploid (A. chinensis × A. eriantha) × A. chinensis backcross families, showing that the A. eriantha allele at this locus increases fruit AsA levels by 250 mg/100 g fresh weight. Inspection of genome composition and recombination in other A. chinensis genetic maps confirmed that the qAsA26.1 region bears hallmarks of suppressed recombination. The molecular fingerprint of this locus was examined in leaves of backcross validation families by RNA sequencing (RNASEQ). This confirmed strong allelic expression bias across this region as well as differential expression of transcripts on other chromosomes. This evidence suggests that the region harbouring qAsA26.1 constitutes a supergene, which may condition multiple pleiotropic effects on metabolism.

11.
Biomark Med ; 12(9): 1035-1048, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30039979

RESUMO

Thymidine kinase 1 (TK1) is a key enzyme in DNA precursor synthesis. It is upregulated during the S phase of the cell cycle and its presence in cells is an indicator of active cell proliferation. In studies since the 1980s, TK1 has been shown as a clinically valuable biomarker for the management of hematological malignancies. However, TK1 activity assays may underestimate serum TK1 in subjects with solid tumors limiting its sensitivity. The development of TK1 immunoassays has made the assay of TK1 more widely available and increased its applicability to solid tumor diseases. This paper will review TK1 as a tumor biomarker with emphasis on recent studies and technologies plus highlight its potential in drug discovery and as a therapeutic target.


Assuntos
Biomarcadores Tumorais/sangue , Proteínas de Neoplasias/sangue , Timidina Quinase/sangue , Neoplasias Hematológicas/patologia , Neoplasias Hematológicas/terapia , Humanos
12.
BMC Res Notes ; 7: 777, 2014 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-25367168

RESUMO

BACKGROUND: The Gibberellin Stimulated-Like (GSL) or Snakin peptides from higher plants are cysteine-rich, with broad spectrum activity against a range of bacterial and fungal pathogens. To detect GSL peptides in applications such as western blot analysis and enzyme-linked immunosorbent assays (ELISA), specific antibodies that recognise GSL peptides are required. However, the intrinsic antimicrobial activity of these peptides is likely to prevent their expression alone in bacterial or yeast expression systems for subsequent antibody production in animal hosts. RESULTS: To overcome this issue we developed an Escherichia coli expression strategy based on the expression of the GSL1 peptide as a His-tagged thioredoxin fusion protein. The DNA sequence for the mature GSL1 peptide from potato (Solanum tuberosum L.) was cloned into the pET-32a expression vector to produce a construct encoding N-terminally tagged his6-thioredoxin-GSL1. The fusion protein was overexpressed in E. coli to produce soluble non-toxic protein. The GSL1 fusion protein could be easily purified by using affinity chromatography to yield ~1.3 mg of his6-thioredoxin-GSL1 per L of culture. The fusion protein was then injected into rabbits for antibody production. Western blot analysis showed that the antibodies obtained from rabbit sera specifically recognised the GSL1 peptide that had been expressed in a wheat germ cell-free expression system. CONCLUSION: We present here the first report of a GSL1 peptide expressed as a fusion protein with thioredoxin that has resulted in milligram quantities of soluble protein to be produced. We have also demonstrated that a wheat germ system can be used to successfully express small quantities of GSL1 peptide useful as positive control in western blot analysis. To our knowledge this is the first report of antibodies being produced against GSL1 peptide. The antibodies will be useful for analysis of GSL1peptides in western blot, localization by immunohistochemistry (IHC) and quantitation by ELISA.


Assuntos
Anticorpos/sangue , Clonagem Molecular , Escherichia coli/metabolismo , Proteínas de Plantas/biossíntese , Proteínas de Plantas/isolamento & purificação , Sequência de Aminoácidos , Animais , Especificidade de Anticorpos , Sequência de Bases , Western Blotting , Cromatografia de Afinidade , Escherichia coli/genética , Histidina/biossíntese , Histidina/isolamento & purificação , Injeções Intravenosas , Dados de Sequência Molecular , Oligopeptídeos/biossíntese , Oligopeptídeos/isolamento & purificação , Proteínas de Plantas/administração & dosagem , Proteínas de Plantas/genética , Proteínas de Plantas/imunologia , Coelhos , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/isolamento & purificação , Tiorredoxinas/biossíntese , Tiorredoxinas/isolamento & purificação
13.
J Agric Food Chem ; 61(44): 10574-81, 2013 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-24147811

RESUMO

Onion and garlic are renowned for their roles as functional foods. The health benefits of garlic are attributed to di-2-propenyl thiosulfinate (allicin), a sulfur compound found in disrupted garlic but not found in disrupted onion. Recently, onions have been grown with repressed lachrymatory factor synthase (LFS) activity, which causes these onions to produce increased amounts of di-1-propenyl thiosulfinate, an isomer of allicin. This investigation into the key health attributes of LFS-silenced (tearless) onions demonstrates that they have some attributes more similar to garlic and that this is likely due to the production of novel thiosulfinate or metabolites. The key finding was that collagen-induced in vitro platelet aggregation was significantly reduced by tearless onion extract over normal onion extract. Thiosulfinate or derived compounds were shown not to be responsible for the observed changes in the inflammatory response of AGS (stomach adenocarcinoma) cells to tumor necrosis factor alpha (TNFα) when pretreated with model onion juices. A preliminary rat feeding trial indicated that the tearless onions may also play a key role in reducing weight gain.


Assuntos
Cebolas/química , Cebolas/enzimologia , Preparações de Plantas/farmacologia , Proteínas de Plantas/genética , Ativação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/farmacologia , Adulto , Animais , Feminino , Inativação Gênica , Humanos , Inflamação/dietoterapia , Inflamação/imunologia , Interleucina-8/genética , Interleucina-8/imunologia , Masculino , Pessoa de Meia-Idade , Cebolas/genética , Cebolas/metabolismo , Preparações de Plantas/metabolismo , Proteínas de Plantas/metabolismo , Agregação Plaquetária/efeitos dos fármacos , Inibidores da Agregação Plaquetária/metabolismo , Ratos , Ratos Sprague-Dawley
14.
Phytochemistry ; 72(9): 882-7, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21470645

RESUMO

Organosulfur compounds are major sinks for assimilated sulfate in onion (Allium cepa L.) and accumulation varies widely due to plant genotype and sulfur nutrition. In order to better characterise sulfur metabolism phenotypes and identify potential control points we compared plant composition and transcript accumulation of the primary sulfur assimilation pathway in the high pungency genotype 'W202A' and the low pungency genotype 'Texas Grano 438' grown hydroponically under S deficient (S-) and S-sufficient (S+) conditions. Accumulation of total S and alk(en)yl cysteine sulfoxide flavour precursors was significantly higher under S+ conditions and in 'W202A' in agreement with previous studies. Leaf sulfate and cysteine levels were significantly higher in 'W202A' and under S+. Glutathione levels were reduced by S- treatment but were not affected by genotype, suggesting that thiol pool sizes are regulated differently in mild and pungent onions. The only significant treatment effect observed on transcript accumulation in leaves was an elevated accumulation of O-acetyl serine thiol-lyase under S-. By contrast, transcript accumulation of all genes in roots was influenced by one or more treatments. APS reductase transcript level was not affected by genotype but was strongly increased by S-. Significant genotype×S treatment effects were observed in a root high affinity-sulfur transporter and ferredoxin-sulfite reductase. ATP sulfurylase transcript levels were significantly higher under S+ and in 'W202A'.


Assuntos
Genótipo , Cebolas/genética , Enxofre/metabolismo , Cisteína/metabolismo , Regulação da Expressão Gênica de Plantas , Cebolas/metabolismo , Sulfatos/metabolismo
15.
Phytochemistry ; 72(9): 888-96, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21459393

RESUMO

To investigate the regulation of sulphur (S)-assimilation in onion further at the biochemical level, the pungent cultivar W202A and the milder cultivar Texas Grano 438 PVP (TG) have been grown in S-sufficient (S(+); 4meqS(-1)) or S-deficient (S(-); 0.1meqS(-1)) growth conditions, and tissues excised at the seedling stage (pre-bulbing; ca. 10-weeks-old) and at the mature stage (bulbing; ca. 16-weeks-old). S-supply negatively influenced adenosine-5'-phosphosulphate (APS) reductase (APR) enzyme activity in both cultivars at bulbing only, and a higher abundance of APR was observed in both cultivars at bulbing in response to low S-supply. In contrast, S-supply significantly influenced ATP sulphurylase (ATPS) activity in leaf tissues of W202A only, and only at bulbing, while an increase in abundance in response to high S-supply was observed for both cultivars at bulbing. To investigate the regulation of the ATPS enzyme activity and accumulation further, activity was shown to decrease significantly in roots at bulbing in the S-deficient treatment in both cultivars, a difference that was only supported by western analyses in W202A. Phylogenetic analysis revealed that AcATPS1 groups in a broad monocot clade with the closest sequences identified in Sorghum bicolour, Zea mays and Oryza sativa, but with some support for a divergence of AcATPS1. Detection of ATPS in leaf extracts after two dimensional gel electrophoresis (2-DE) revealed that the protein may undergo post-translational modification with a differential pattern of ATPS accumulation detected in both cultivars over the developmental progression from the seedling to the bulbing stage. Treatment of leaf extracts of W202A to dephosphorylate proteins resulted in the loss of immuno-recognised ATPS spots after 2-DE separation, although enzyme activity was not influenced. These results are discussed in terms of the tiers of control that operate at the biochemical level in the reductive S-assimilation pathway in a S-accumulating species particularly during the high-S-demanding bulbing stage.


Assuntos
Genótipo , Cebolas/enzimologia , Sulfato Adenililtransferase/genética , Enxofre/metabolismo , Cloroplastos/enzimologia , Isoenzimas/genética , Isoenzimas/metabolismo , Cebolas/genética , Oxirredutases atuantes sobre Doadores de Grupo Enxofre/metabolismo , Filogenia , Processamento de Proteína Pós-Traducional , Sulfato Adenililtransferase/metabolismo
18.
Plant Physiol ; 147(4): 2096-106, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18583530

RESUMO

Through a single genetic transformation in onion (Allium cepa), a crop recalcitrant to genetic transformation, we suppressed the lachrymatory factor synthase gene using RNA interference silencing in six plants. This reduced lachrymatory synthase activity by up to 1,544-fold, so that when wounded the onions produced significantly reduced levels of tear-inducing lachrymatory factor. We then confirmed, through a novel colorimetric assay, that this silencing had shifted the trans-S-1-propenyl-l-cysteine sulfoxide breakdown pathway so that more 1-propenyl sulfenic acid was converted into di-1-propenyl thiosulfinate. A consequence of this raised thiosulfinate level was a marked increase in the downstream production of a nonenzymatically produced zwiebelane isomer and other volatile sulfur compounds, di-1-propenyl disulfide and 2-mercapto-3,4-dimethyl-2,3-dihydrothiophene, which had previously been reported in trace amounts or had not been detected in onion. The consequences of this dramatic simultaneous down- and up-regulation of secondary sulfur products on the health and flavor attributes of the onion are discussed.


Assuntos
Cebolas/genética , Proteínas de Plantas/genética , Interferência de RNA , Enxofre/metabolismo , Liases de Carbono-Enxofre/metabolismo , Dados de Sequência Molecular , Cebolas/enzimologia , Cebolas/metabolismo , Fenótipo , Proteínas de Plantas/metabolismo , Precursores de Proteínas/genética , Precursores de Proteínas/metabolismo , RNA Mensageiro/metabolismo , Ácidos Sulfínicos/análise , Ácidos Sulfínicos/química , Enxofre/química , Transformação Genética , Volatilização
19.
Toxicol Pathol ; 36(3): 397-409, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-18441258

RESUMO

Immunohistochemical studies for kidney injury molecule-1 (Kim-1), renal papillary antigen-1 (RPA-1), and renal papillary antigen-2 (RPA-2) were conducted to explore their relationship to inducible nitric oxide synthase (iNOS) and nitrotyrosine expression. Male Sprague-Dawley rats were exposed to gentamicin (100 mg/kg/day Gen, sc, for 3 days), mercury (0.25 mg Hg/kg, iv, single dose), or chromium (5 mg Cr/kg, sc, single dose) and kidney tissue was examined 24 hours or 72 hours after the last dose of the nephrotoxicant. Another group of kidneys was evaluated 24 hours after rats were administered 3 daily doses (50, 100, 150, 200, or 300 mg/kg/day) of Gen. Gen- and Cr-treated rats exhibited increased immunoreactivity of Kim-1, RPA-1, and RPA-2 largely in the S1/S2 segments and to a lesser extent in the S3 segments of the proximal tubule of the kidney, whereas Hg-treated rats showed increased immunoreactivity of Kim-1, RPA-1, and RPA-2 in the S3 segments. Up-regulation of Kim-1, RPA-1, and RPA-2 expression correlated with injured tubular epithelial cells and also correlated with immunoreactivity of iNOS and nitrotyrosine. It is possible that iNOS activation with nitrotyrosine production in injured nephron segments may be involved in the induction of Kim-1, RPA-1, and RPA-2 following exposure to nephrotoxicants.


Assuntos
Antígenos/metabolismo , Moléculas de Adesão Celular/metabolismo , Rim/efeitos dos fármacos , Óxido Nítrico Sintase Tipo II/metabolismo , Tirosina/análogos & derivados , Xenobióticos/toxicidade , Animais , Apoptose/efeitos dos fármacos , Biomarcadores/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Técnica Indireta de Fluorescência para Anticorpo , Gentamicinas/toxicidade , Técnicas Imunoenzimáticas , Imuno-Histoquímica , Rim/metabolismo , Rim/patologia , Túbulos Renais Proximais/efeitos dos fármacos , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Masculino , Cloreto de Mercúrio/toxicidade , Ácido Peroxinitroso/metabolismo , Dicromato de Potássio/toxicidade , Ratos , Ratos Sprague-Dawley , Tirosina/metabolismo , Regulação para Cima
20.
Acta Neurochir Suppl ; 102: 217-21, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19388319

RESUMO

BACKGROUND: The BrainIT group works collaboratively on developing standards for collection and analyses of data from brain injured patients towards providing a more efficient infrastructure for assessing new health technology. MATERIALS AND METHODS: Over a 2 year period, core dataset data (grouped by nine categories) were collected from 200 head-injured patients by local nursing staff. Data were uploaded by the BrainIT web and random samples of received data were selected automatically by computer for validation by data validation (DV) research nurse staff against gold standard sources held in the local centre. Validated data was compared with original data sent and percentage error rates calculated by data category. FINDINGS: Comparisons, 19,461, were made in proportion to the size of the data received with the largest number checked in laboratory data (5,667) and the least in the surgery data (567). Error rates were generally less than or equal to 6%, the exception being the surgery data class where an unacceptably high error rate of 34% was found. CONCLUSIONS: The BrainIT core dataset (with the exception of the surgery classification) is feasible and accurate to collect. The surgery classification needs to be revised.


Assuntos
Encéfalo/fisiopatologia , Comportamento Cooperativo , Traumatismos Craniocerebrais/patologia , Serviços de Informação/estatística & dados numéricos , Monitorização Fisiológica , Bases de Dados Factuais/estatística & dados numéricos , Humanos , Armazenamento e Recuperação da Informação
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA