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1.
Sci Total Environ ; 905: 166973, 2023 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-37699488

RESUMO

A challenge in bee protection is to assess the risks of pesticide-pathogen interactions. Lotmaria passim, a ubiquitous unicellular parasite in honey bees, is considered harmful under specific conditions. Imidacloprid causes unpredictable side effects. Research indicates that both L. passim and imidacloprid may affect the physiology, behavior, immunity, microbiome and lifespan of honey bees. We designed cage experiments to test whether the infection of L. passim is affected by a sublethal dose of imidacloprid. Workers collected at the time of emergence were exposed to L. passim and 2.5 µg/L imidacloprid in the coexposure treatment group. First, samples of bees were taken from cages since they were 5 days old and 3 days postinfection, i.e., after finishing an artificial 24 h L. passim infection. Additional bees were collected every two additional days. In addition, bees frozen at the time of emergence and collected from the unexposed group were analyzed. Abdomens were analyzed using qPCR to determine parasite load, while corresponding selected heads were subjected to a label-free proteomic analysis. Our results show that bees are free of L. passim at the time of emergence. Furthermore, imidacloprid considerably increased the prevalence as well as parasite loads in individual bees. This means that imidacloprid facilitates infection, enabling faster parasite spread in a colony and potentially to surrounding colonies. The proteomic analysis of bee heads showed that imidacloprid neutralized the increased transferrin 1 expression by L. passim. Importantly, this promising marker has been previously observed to be upregulated by infections, including gut parasites. This study contributes to understanding the side effects of imidacloprid and demonstrates that a single xenobiotic/pesticide compound can interact with the gut parasite. Our methodology can be used to assess the effects of different compounds on L. passim.


Assuntos
Inseticidas , Parasitos , Praguicidas , Trypanosomatina , Abelhas , Animais , Prevalência , Proteômica , Trypanosomatina/parasitologia , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Inseticidas/toxicidade
2.
Gut ; 72(12): 2286-2293, 2023 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-37652677

RESUMO

BACKGROUND: Endoluminal radiofrequency ablation (RFA) has been promoted as palliative treatment for patients with cholangiocarcinoma (CCA) and pancreatic ductal adenocarcinoma (PDAC) in order to improve biliary drainage and eventually prolong survival. No high level evidence is, however, available on this technique. DESIGN: In this randomised controlled study, we compared endoluminal RFA plus stenting with stenting alone (control group) in patients with malignant biliary obstruction; metal stents were primarily placed. Primary outcome was overall survival; secondary outcomes were stent patency, quality of life and adverse events. In a superiority design, survival was assumed to be doubled by RFA as compared with 6.4 months in the control group (n=280). RESULTS: A total of 161 patients (male:female 90:71, mean age 71±9 years) were randomised before recruitment was terminated for futility after an interim analysis. Eighty-five patients had CCA (73 hilar, 12 distal) and 76 had pancreatic cancer. There was no difference in survival in both subgroups: for patients with CCA, median survival was 10.5 months (95% CI 6.7 to 18.3) in the RFA group vs 10.6 months (95% CI 9.0 to 24.8), p=0.58)) in the control group. In the subgroup with pancreatic cancer, median survival was 6.4 months (95% CI 4.3 to 9.7) for the RFA vs 7.7 months (95% CI 5.6 to 11.3), p=0.73) for the control group. No benefit was seen in the RFA group with regard to stent patency (at 12 months 40% vs 36% in CCA and 66% vs 65% in PDAC), and quality of life was unchanged by either treatment and comparable between the groups. Adverse events occurred in seven patients in each groups. CONCLUSION: A combination of endoluminal RFA and stenting was not superior to stenting alone in prolonging survival or improving stent patency in patients with malignant biliary obstruction. TRIAL REGISTRATION NUMBER: NCT03166436.


Assuntos
Neoplasias dos Ductos Biliares , Ablação por Cateter , Colangiocarcinoma , Colestase , Neoplasias Pancreáticas , Ablação por Radiofrequência , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Idoso , Idoso de 80 Anos ou mais , Qualidade de Vida , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Neoplasias Pancreáticas/complicações , Neoplasias Pancreáticas/cirurgia , Stents/efeitos adversos , Colestase/etiologia , Colestase/cirurgia , Neoplasias dos Ductos Biliares/complicações , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-Hepáticos/cirurgia , Resultado do Tratamento , Neoplasias Pancreáticas
3.
Plant Physiol Biochem ; 198: 107683, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37062127

RESUMO

Heat stress is a frequent environmental constraint. Phytohormones can significantly affect plant thermotolerance. This study compares the effects of exogenous cytokinin meta-topolin-9-(tetrahydropyran-2-yl)purine (mT9THP) on rice (Oryza sativa) under control conditions, after acclimation by moderate temperature (A; 37 °C, 2h), heat stress (HS; 45 °C, 6h) and their combination (AHS). mT9THP is a stable cytokinin derivative that releases active meta-topolin gradually, preventing the rapid deactivation reported after exogenous cytokinin application. Under control conditions, mT9THP negatively affected jasmonic acid in leaves and abscisic and salicylic acids in crowns (meristematic tissue crucial for tillering). Exogenous cytokinin stimulated the emission of volatile organic compounds (VOC), especially 2,3-butanediol. Acclimation upregulated trans-zeatin, expression of stress- and hormone-related genes, and VOC emission. The combination of acclimation and mT9THP promoted the expression of stress markers and antioxidant enzymes and moderately increased VOC emission, including 2-ethylhexyl salicylate or furanones. AHS and HS responses shared some common features, namely, increase of ethylene precursor aminocyclopropane-1-carboxylic acid (ACC), cis-zeatin and cytokinin methylthio derivatives, as well as the expression of heat shock proteins, alternative oxidases, and superoxide dismutases. AHS specifically induced jasmonic acid and auxin indole-3-acetic acid levels, diacylglycerolipids with fewer double bonds, and VOC emissions [e.g., acetamide, lipoxygenase (LOX)-derived volatiles]. Under direct HS, exogenous cytokinin mimicked some positive acclimation effects. The combination of mT9THP and AHS had the strongest thermo-protective effect, including a strong stimulation of VOC emissions (including LOX-derived ones). These results demonstrate for the first time the crucial contribution of volatiles to the beneficial effects of cytokinin and AHS on rice thermotolerance.


Assuntos
Oryza , Termotolerância , Compostos Orgânicos Voláteis , Citocininas/metabolismo , Oryza/metabolismo , Zeatina/metabolismo , Aclimatação , Expressão Gênica
4.
Ann Transplant ; 27: e938114, 2022 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-36523129

RESUMO

BACKGROUND Acute pancreatitis (AP) is a relatively rare but serious complication that can occur after organ transplantation. MATERIAL AND METHODS The aim of this study was to evaluate the incidence, potential risk factors, and course of AP in patients following liver transplantation at a single large-volume transplant center. RESULTS Out of a total of 1850 transplanted patients, 49 (2.8%) were diagnosed with AP. Of this group, 37 (75.5%) had a mild form of AP and 12 (24.5%) had a severe form of AP. The mortality rate was 10% overall and 42% in the group of patients with severe AP. An early form of AP (<30 days from transplantation) occurred in 13 patients (26.5%), most of whom presented with severe AP (10 patients, 76.9%); 4 patients died (40%). A late form of AP was diagnosed in 36 patients (73.5%), most of whom had mild AP (34 patients, 94.4%); 1 of 2 patients with severe AP died. The most common AP etiologies were post-ERCP (38.8%), idiopathic (34.7%), and postoperative (18.4%). Chronic HBV infection was a risk factor for development of AP (P=0.01). CONCLUSIONS AP in liver transplant recipients was more frequent and more severe than in the general population. This unfavorable course was associated with the occurrence of AP in the early post-transplant period. Liver transplantation due to complications of HBV infection was a risk factor for the development of AP.


Assuntos
Transplante de Fígado , Pancreatite , Humanos , Pancreatite/etiologia , Pancreatite/diagnóstico , Transplante de Fígado/efeitos adversos , Doença Aguda , Fatores de Risco , Incidência
5.
Biomedicines ; 10(6)2022 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-35740353

RESUMO

Radiofrequency ablation (RFA) is a mini-invasive loco-regional ablation technique that is increasingly being used as a palliative treatment for pancreatic cancer and cholangiocarcinoma. Ablation-triggered immune system stimulation has been proposed as a mechanism behind the systemic effects of RFA. The aim of our study was to investigate the immune response to endoluminal biliary RFA. Peripheral blood samples were collected from patients with pancreatic cancer and cholangiocarcinoma randomised to receive endoluminal biliary radiofrequency ablation + stent (19 patients) or stent only (21 patients). We observed an early increase in IL-6 levels and a delayed increase in CXCL1, CXCL5, and CXCL11 levels as well as an increase in CD8+ and NK cells. However, these changes were not specific to RFA treatment. Explicitly in response to RFA, we observed a delayed increase in serum CXCL1 levels and an early decrease in the number of anti-inflammatory CD206+ blood monocytes. Our study provides the first evidence of endoluminal biliary RFA-based regulation of the systemic immune response in patients with pancreatic cancer and cholangiocarcinoma. These changes were characterised by a general inflammatory response. RFA-specific activation of the adaptive immune system was not confirmed.

6.
World J Hepatol ; 14(5): 1038-1046, 2022 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-35721285

RESUMO

BACKGROUND: Transjugular intrahepatic portosystemic shunt (TIPS) is a method used to decrease portal hypertension. Biliary stricture is the rarest of the complications associated with this procedure with only 12 cases previously reported in the literature. None of these cases have documented the resolution of biliary stenosis induced by a stent graft. The only curative solutions reported are liver transplantation or bypassing the stenosis with an artificial biliary tract using advanced endoscopic techniques. CASE SUMMARY: This is the first reported case of biliary obstruction secondary to TIPS placement in a transplanted liver. In our patient, a portosystemic shunt was created to treat severe veno-occlusive liver graft disease manifesting itself primarily by fluid retention. A cholestatic liver lesion and cholangitis with abscesses developed due to a stent graft-induced stricture in the dorsal segment of the right hepatic duct and the stricture diminished following percutaneous drainage. Endoscopic drainage was performed after unsuccessful removal of the percutaneous catheter resulting in a bilio-cutaneous fistula. Although the liver graft now functions well, the stricture remains refractory even after 44 mo of treatment. CONCLUSION: Biliary strictures caused by TIPS in both transplanted and native livers seem refractory to endoscopic treatment.

7.
World J Gastrointest Oncol ; 13(10): 1383-1396, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34721772

RESUMO

Cholangiocarcinoma and pancreatic cancer are the most common causes of malignant biliary obstruction. The majority of patients are diagnosed at a late stage when surgical resection is rarely possible. In these cases, palliative chemotherapy and radiotherapy provide only limited benefit and are associated with poor survival. Radiofrequency ablation (RFA) is a procedure for locoregional control of tumours, whereby a high-frequency alternating current turned into thermal energy causes coagulative necrosis of the tissue surrounding the catheter. The subsequent release of debris and tumour antigens by necrotic cells can stimulate local and systemic immunity. The development of endoluminal RFA catheters has led to the emergence of endoscopically delivered RFA, a treatment mainly used for malignant biliary strictures to prolong survival and/or stent patency. Other indications include recanalisation of occluded biliary stents and treatment of intraductal ampullary adenoma or benign biliary strictures. This article presents a comprehensive review of endobiliary RFA, mainly focusing on its use in patients with malignant biliary obstruction. The available data suggest that biliary RFA may be a promising modality, having positive impacts on survival and stent patency and boasting a reasonable safety profile. However, further studies with better characterised and stratified patient populations are needed before the method becomes accepted within routine clinical practice.

8.
Front Plant Sci ; 12: 726881, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34712254

RESUMO

Interfering RNA technology has been established as an effective strategy to protect plants against viral infection. Despite this success, interfering RNA (RNAi) has rarely been applied due to the regulatory barriers that confront genetically engineered plants and concerns over possible environmental and health risks posed by non-endogenous small RNAs. 'HoneySweet' was developed as a virus-resistant plum variety that is protected by an RNAi-mediated process against Sharka disease caused by the plum pox virus. 'HoneySweet' has been approved for cultivation in the United States but not in countries where the plum pox virus is endemic. In this study, we evaluated the long-term efficacy of virus resistance in 'HoneySweet,' the nature and stability of its sRNA profile, and the potential health risks of consuming 'HoneySweet' plums. Graft-challenged 'HoneySweet' trees carrying large non-transgenic infected limbs remained virus-free after more than 10 years in the field, and the viral sequences from the non-transgenic infected limbs showed no evidence of adaptation to the RNAi-based resistance. Small RNA profiling revealed that transgene-derived sRNA levels were stable across different environments and, on average, were more than 10 times lower than those present in symptom-less fruits from virus-infected trees. Comprehensive 90-day mouse feeding studies showed no adverse health impacts in mice, and there was no evidence for potential siRNA off-target pathologies predicted by comparisons of the most abundant transgene-derived sRNAs to the mouse genome. Collectively, the data confirmed that RNAi provides a highly effective, stable, and safe strategy to combat virus diseases in crop plants.

9.
Vnitr Lek ; 67(2): 76-83, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34074105

RESUMO

IgG4-related disease is a recently defined clinical entity that can manifest itself in any organ. The most common gastrointestinal manifestations are diseases of the pancreas (autoimmune pancreatitis type 1) and biliary tree (IgG4-associated cholangitis); involvement of liver parenchyma is uncommon and the affection of tubular organs is very rare. IgG4-related pancreatitis and cholangitis can mimic malignancies in their clinical presentation. Diagnosis is often difficult and requires careful evaluation of the combination of symptoms, serology and imaging findings, while adhering to the established diagnostic criteria. The first line of treatment is the administration of corticoids and the remission is achieved in the vast majority of patients. In case of contraindication, intolerance or failure of corticotherapy, patients should receive B cell depletion therapy (rituximab). Based on the available knowledge, monotherapy with other immunosuppressants is not considered to be sufficiently effective. Some patients may benefit from maintenance treatment to prevent relapse, which is otherwise common in both IgG4-related pancreatitis and cholangitis. Recognized IgG4-related disease has a good prognosis, but some patients develop irreversible fibrotic changes in the affected organ with consequent dysfunction; the possible association of the disease with a higher risk of malignancy has not yet been reliably elucidated.


Assuntos
Doenças Autoimunes , Colangite Esclerosante , Colangite , Gastroenterologia , Doença Relacionada a Imunoglobulina G4 , Pancreatite , Doenças Autoimunes/diagnóstico , Humanos , Doença Relacionada a Imunoglobulina G4/diagnóstico , Pancreatite/diagnóstico
10.
Int J Mol Sci ; 22(5)2021 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-33800491

RESUMO

Plant survival in temperate zones requires efficient cold acclimation, which is strongly affected by light and temperature signal crosstalk, which converge in modulation of hormonal responses. Cold under low light conditions affected Arabidopsis responses predominantly in apices, possibly because energy supplies were too limited for requirements of these meristematic tissues, despite a relatively high steady-state quantum yield. Comparing cold responses at optimal light intensity and low light, we found activation of similar defence mechanisms-apart from CBF1-3 and CRF3-4 pathways, also transient stimulation of cytokinin type-A response regulators, accompanied by fast transient increase of trans-zeatin in roots. Upregulated expression of components of strigolactone (and karrikin) signalling pathway indicated involvement of these phytohormones in cold responses. Impaired response of phyA, phyB, cry1 and cry2 mutants reflected participation of these photoreceptors in acquiring freezing tolerance (especially cryptochrome CRY1 at optimal light intensity and phytochrome PHYA at low light). Efficient cold acclimation at optimal light was associated with upregulation of trans-zeatin in leaves and roots, while at low light, cytokinin (except cis-zeatin) content remained diminished. Cold stresses induced elevation of jasmonic acid and salicylic acid (in roots). Low light at optimal conditions resulted in strong suppression of cytokinins, jasmonic and salicylic acid.


Assuntos
Aclimatação , Proteínas de Arabidopsis , Arabidopsis , Congelamento , Regulação da Expressão Gênica de Plantas , Luz , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/biossíntese , Proteínas de Arabidopsis/genética
11.
Front Plant Sci ; 12: 799249, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35111178

RESUMO

Inter-organ communication and the heat stress (HS; 45°C, 6 h) responses of organs exposed and not directly exposed to HS were evaluated in rice (Oryza sativa) by comparing the impact of HS applied either to whole plants, or only to shoots or roots. Whole-plant HS reduced photosynthetic activity (F v /F m and QY_Lss ), but this effect was alleviated by prior acclimation (37°C, 2 h). Dynamics of HSFA2d, HSP90.2, HSP90.3, and SIG5 expression revealed high protection of crowns and roots. Additionally, HSP26.2 was strongly expressed in leaves. Whole-plant HS increased levels of jasmonic acid (JA) and cytokinin cis-zeatin in leaves, while up-regulating auxin indole-3-acetic acid and down-regulating trans-zeatin in leaves and crowns. Ascorbate peroxidase activity and expression of alternative oxidases (AOX) increased in leaves and crowns. HS targeted to leaves elevated levels of JA in roots, cis-zeatin in crowns, and ascorbate peroxidase activity in crowns and roots. HS targeted to roots increased levels of abscisic acid and auxin in leaves and crowns, cis-zeatin in leaves, and JA in crowns, while reducing trans-zeatin levels. The weaker protection of leaves reflects the growth strategy of rice. HS treatment of individual organs induced changes in phytohormone levels and antioxidant enzyme activity in non-exposed organs, in order to enhance plant stress tolerance.

12.
Biomolecules ; 10(4)2020 03 30.
Artigo em Inglês | MEDLINE | ID: mdl-32235474

RESUMO

Myo-inositol exerts many cellular functions, which include osmo-protection, membrane functioning, and secondary messaging. Its Na+/myo-inositol co-transporter SLC5A3 is expressed in muscle tissue and further accumulates in myositis. In this study we focused on the peculiar subgroup of sporadic inclusion body myositis (IBM), in which auto-inflammatory responses and degenerative changes co-exist. A cohort of nine patients was selected with clinically confirmed IBM, in which SLC5A3 protein was immune-localized to the different tissue constituents using immunofluorescence, and expression levels were evaluated using Western blotting. In normal muscle tissue, SLC5A3 expression was restricted to blood vessels and occasional low levels on muscle fiber membranes. In IBM tissues, SLC5A3 staining was markedly increased, with discontinuous staining of the muscle fiber membranes, and accumulation of SLC5A3 near inclusions and on the rims of vacuoles. A subset of muscle-infiltrating auto-aggressive immune cells was SLC5A3 positive, of which most were T-cells and M1 lineage macrophages. We conclude that SLC5A3 is overexpressed in IBM muscle, where it associates with protein aggregation and inflammatory infiltration. Based on our results, functional studies could be initiated to explore the possibilities of therapeutic osmolyte pathway intervention for preventing protein aggregation in muscle cells.


Assuntos
Proteínas de Choque Térmico/metabolismo , Inositol/metabolismo , Miosite de Corpos de Inclusão/metabolismo , Simportadores/metabolismo , Idoso , Idoso de 80 Anos ou mais , Transporte Biológico , Feminino , Humanos , Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade
13.
Plants (Basel) ; 9(1)2020 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-31906504

RESUMO

Barley yellow dwarf virus (BYDV) causes an often-devastating disease of cereals that is most effectively controlled by using plant genotypes that are resistant or tolerant to the virus. New barley lines Vir8:3 and Vir13:8, with pyramided resistance genes against different pathogens and resistance gene Ryd2 against BYDV, are currently being tested. Because microRNAs (miRNAs) are associated with antiviral plant defense, here we compared the miRNA profiles in these lines and in cultivar Wysor (carrying one resistance gene, Ryd2), with and without BYDV infection and after feeding by virus-free aphids, to determine whether the miRNA profile in the resistant variety bear similarities with the newly developed lines. The BYDV titer for each group was also determined and compared to the titer in sensitive cultivar Graciosa. Among 746 miRNAs identified in barley, 66 were known miRNAs, and 680 were novel. The expression of 73 miRNAs differed significantly after BYDV infection, including the strong, specific upregulation of novel miRNA10778 that was conserved across all the barley genotypes. This miRNA belongs to the H box and ACA box (H/ACA) snoR14 family of RNAs (Rf01280) and is associated with pseudourydilation. The expression of 48 miRNAs also differed depending on the barley genotype. The profile of miRNAs expressed in Vir8:3 and Vir13:8 in response to BYDV was similar and differed from that of Wysor. Insights into the expression patterns of miRNAs in response to BYDV in barley provided here will benefit further studies toward understanding the resistance mechanisms and developing novel strategies against virus infections.

14.
J Appl Genet ; 60(3-4): 305-317, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31286439

RESUMO

The solute carrier (SLC) group of membrane transport proteins is crucial for cells via their control of import and export of vital molecules across the cellular membrane. Defects in these transporters with narrow substrate specificities cause monogenic disorders, giving us essential clues of their precise roles in cellular functioning. The SLC5 family in particular has been linked to various human diseases, of mild and severe phenotype as well as high and low prevalence. In this review, we describe the effects on health of SLC5 dysfunction and dysregulation by summarizing findings in patients with transporter gene defects. Patients display a plethora of pathologies which include glucose/galactose malabsorption, familiar renal glycosuria, thyroid dyshormonogenesis, and distal hereditary motor neuronopathies. In addition, the therapeutic potential of intervening in transporter activities for treating common diseases such as diabetes and cancer is explored.


Assuntos
Diabetes Mellitus/genética , Transtornos do Metabolismo de Glucose/genética , Neoplasias/genética , Proteínas Carreadoras de Solutos/genética , Diabetes Mellitus/metabolismo , Transtornos do Metabolismo de Glucose/metabolismo , Humanos , Neoplasias/metabolismo , Proteínas de Transporte de Sódio-Glucose
15.
Plant Dis ; 103(8): 2057-2064, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31241012

RESUMO

The bird cherry-oat aphid (Rhopalosiphum padi (L.)) is one of the most detrimental pests of cereals, causing harm mainly by transmitting Barley yellow dwarf virus (BYDV). R. padi migration has been monitored since 1992 using suction traps at five sites in the Czech Republic. The count data were subjected to the following different analyses: (i) the minimum temperature thresholds for the aphids to take off were determined; (ii) a partial redundancy analysis using the minimum, average, and maximum temperatures, as well as the wind speed, the precipitation total, and past aphid migration descriptors was performed to explain the relationship between aphid occurrences and weather patterns; and (iii) three types of models from the field of machine learning were used to predict aphid occurrences. According to our findings, (i) in Central Europe, 8°C is the temperature threshold for R. padi migration unless insufficient daylight delays the take-off; (ii) weather conditions occurring roughly 9 months before R. padi migration influence the migration size; (iii) the duration of the summer migration influences the autumn migration size; and (iv) the daytime and nighttime temperatures in the autumn determine the summer peak, whereas winter frosts and precipitation influence the autumn peak.


Assuntos
Migração Animal , Afídeos , Hordeum , Luteovirus , Animais , Afídeos/fisiologia , Afídeos/virologia , República Tcheca , Hordeum/virologia , Luteovirus/fisiologia
16.
Artigo em Inglês | MEDLINE | ID: mdl-30666235

RESUMO

Purpose: The purpose of the study was to determine the intraocular pressure response to normobaric hypoxia and the consequent recovery under additional well-controlled ambient conditions. Second, the study attempted to determine if the intraocular pressure changes were dependent on its baseline, initial heart rate, sex and arterial oxygen saturation. Methods: Thirty-eight visually healthy volunteers (23 women and 15 men) of an average age 25.2 ± 3.8 years from 49 recruited participants met the inclusion criteria and performed the complete test. Initial intraocular pressure (baseline), heart rate, and arterial oxygen saturation were measured after 7 min of rest under normal ambient conditions at an altitude 250 m above sea level. Each subject then underwent a 10 min normobaric hypoxic exposure and a subsequent 7 min recovery under normoxic conditions. Within hypoxic period, subjects were challenged to breathe hypoxic gas mixture with fraction of inspired oxygen of 9.6% (~6.200 m above sea level). Intraocular pressure and arterial oxygen saturation were re-measured at 4 and 10 min during the hypoxia and at 7 min after hypoxia termination. Results: Intraocular pressure increased in 1.2 mmHg ± 1.9 mmHg and 0.9 mmHg ± 2.3 mmHg at 4 and 10 min during the hypoxic period and returned approximately to the baseline at 7 min of recovery. The influence of sex was not statistically significant. The arterial oxygen saturation decreased in 14.9 ± 4.2% at min 4 and 18.4 ± 5.8% at min 10 during hypoxia and returned to the resting value at 7 min of recovery. The decrease was slightly higher in the case of women if compared with men. The hypoxia induced changes in intraocular pressure were significantly correlated with the arterial oxygen saturation changes, whereas the relationship with intraocular pressure baseline and initial heart rate were insignificant. Conclusion: There was a significant increase in intraocular pressure as a response to short-term normobaric hypoxia, which returned to the baseline in 7 min after hypoxia. The increase was dependent on the induced oxygen desaturation.

17.
BMC Plant Biol ; 10: 146, 2010 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-20630112

RESUMO

BACKGROUND: Reference genes are commonly used as the endogenous normalisation measure for the relative quantification of target genes. The appropriate application of quantitative real-time PCR (RT-qPCR), however, requires the use of reference genes whose level of expression is not affected by the test, by general physiological conditions or by inter-individual variability. For this purpose, seven reference genes were investigated in tissues of the most important cereals (wheat, barley and oats). Titre of Barley yellow dwarf virus (BYDV) was determined in oats using relative quantification with different reference genes and absolute quantification, and the results were compared. RESULTS: The expression of seven potential reference genes was evaluated in tissues of 180 healthy, physiologically stressed and virus-infected cereal plants. These genes were tested by RT-qPCR and ranked according to the stability of their expression using three different methods (two-way ANOVA, GeNorm and NormFinder tools). In most cases, the expression of all genes did not depend on abiotic stress conditions or virus infections. All the genes showed significant differences in expression among plant species. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-tubulin (TUBB) and 18S ribosomal RNA (18S rRNA) always ranked as the three most stable genes. On the other hand, elongation factor-1 alpha (EF1A), eukaryotic initiation factor 4a (EIF4A), and 28S ribosomal RNA (28S rRNA) for barley and oat samples; and alpha-tubulin (TUBA) for wheat samples were consistently ranked as the less reliable controls.The BYDV titre was determined in two oat varieties by RT-qPCR using three different quantification approaches. There were no significant differences between the absolute and relative quantifications, or between quantification using GAPDH + TUBB + TUBA +18S rRNA and EF1A + EIF4A + 28S rRNA. However, there were discrepancies between the results of individual assays. CONCLUSIONS: The geometric average of GAPDH, 18S rRNA and TUBB is suitable for normalisation of BYDV quantification in barley tissues. For wheat and oat samples, a combination of four genes is necessary: GAPDH, 18S rRNA, TUBB and EIF4A for wheat; and GAPDH, 18S rRNA, TUBB and TUBA for oat is recommended.


Assuntos
Grão Comestível/genética , Grão Comestível/virologia , Perfilação da Expressão Gênica/métodos , Genes de Plantas/genética , Luteovirus/fisiologia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , RNA Ribossômico 18S/análise , RNA Ribossômico 18S/genética , Reprodutibilidade dos Testes , Reação em Cadeia da Polimerase Via Transcriptase Reversa/métodos , Carga Viral
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