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INTRODUCTION: Video capsule endoscopy and balloon-assisted enteroscopy are complementary diagnostic methods in the study of small bowel bleeding, and different factors can affect their diagnostic yield. AIMS: To define the level of agreement between video capsule endoscopy and enteroscopy in small bowel bleeding, according to the type of lesion, in a cohort of patients at a tertiary care referral center. MATERIALS AND METHODS: A retrospective study was conducted that included 428 capsule endoscopies performed within the time frame of 2011 and 2019 at our healthcare institution. Seventy-four video capsule endoscopies, followed by enteroscopy, in 71 patients suspected of presenting with small bowel bleeding, were analyzed. RESULTS: Mean patient age was 63.9 ± 13.5 years and 42 patients were women. The two diagnostic procedures were performed. Overall diagnostic yield of positive findings between video capsule endoscopy and enteroscopy was 86.5% vs. 58.1%, respectively (p = 0.0527). Agreement between video capsule endoscopy and enteroscopy for positive pathologic findings was weak (Ik = 0.17, 95% CI: -0.0097-0.3543), but according to lesion type, it was good for inflammatory lesions (Ik = 0.71, 95% CI: 0.5182-0.9119) and moderate for angiectasias (Ik = 0.45, 95% CI: 0.2469-0.6538) and tumors (Ik = 0.40, 95% CI: 0.1217-0.6794). The results between the two methods differed in 38 patients (51.3%). There was complete intestinal capsule retention in one patient (1.4%) and active bleeding in 13 (17.6%). CONCLUSIONS: The present study showed that the two techniques had a similar overall detection rate for small bowel lesions, but the type of lesion was the main factor that could modify diagnostic agreement.
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Solid state physics deals with systems composed of atoms with strongly bound electrons. The tunneling probability of each electron is determined by interactions that typically extend to neighboring sites, as their corresponding wave amplitudes decay rapidly away from an isolated atomic core. This kind of description is essential in condensed-matter physics, and it rules the electronic transport properties of metals, insulators and many other solid-state systems. The corresponding phenomenology is well captured by tight-binding models, where the electronic band structure emerges from atomic orbitals of isolated atoms plus their coupling to neighboring sites in a crystal. In this work, a mechanical system that emulates dynamically a quantum tightly bound electron is built. This is done by connecting mechanical resonators via locally periodic aluminum bars acting as couplers. When the frequency of a particular resonator lies within the frequency gap of a coupler, the vibrational wave amplitude imitates a bound electron orbital. The localization of the wave at the resonator site and its exponential decay along the coupler are experimentally verified. The quantum dynamical tight-binding model and frequency measurements in mechanical structures show an excellent agreement. Some applications in atomic and condensed matter physics are suggested.
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We report the combined antibacterial/tissue regeneration responses to thermal burns promoted by functional chitosan/silver nanocomposites (CS/nAg) with ultralow silver content (0.018wt.%, 7-30nm). Our approach allows one to produce CS/nAg nanocomposites without silver nanoparticles (nAg) agglomeration, with bactericide potency higher than 1wt.% of nAg (ca. 10nm) content and, promoting the healing process in controlled thermal burns. CS/nAg films exhibit high antibacterial activity against S. aureus and P. aeruginosa after 1.5h of incubation, demonstrating the bacterial penetration into hydrated films and their interaction with nAg. Additionally, exceptional healing of induced thermal burns was obtained by increasing myofibroblasts, collagen remodeling, and blood vessel neoformation. These factors are associated with epiderma regeneration after 7days of treatment with no nAg release. Our results corroborate the controlled synthesis of nAg embedded in CS matrix with combined antibacterial/biocompatibility properties aiming to produce functional nanocomposites with potential use in wound dressing and health care applications.
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Materiais Biocompatíveis/farmacologia , Queimaduras/fisiopatologia , Quitosana/química , Nanocompostos/química , Regeneração/efeitos dos fármacos , Prata/química , Animais , Antibacterianos/química , Antibacterianos/farmacologia , Materiais Biocompatíveis/química , Masculino , Ratos , Ratos WistarRESUMO
Coherent transport phenomena are difficult to observe due to several sources of decoherence. For instance, in the electronic transport through quantum devices the thermal smearing and dephasing, the latter induced by inelastic scattering by phonons or impurities, destroy phase coherence. In other wave systems, the temperature and dephasing may not destroy the coherence and can then be used to observe the underlying wave behaviour of the coherent phenomena. Here, we observe coherent transmission of mechanical waves through a two-dimensional elastic Sinai billiard with two waveguides. The flexural-wave transmission, performed by non-contact means, shows the quantization when a new mode becomes open. These measurements agree with the theoretical predictions of the simplest model highlighting the universal character of the transmission fluctuations.
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In several species, seed germination is regulated by light in a way that restricts seedling emergence to the environmental conditions that are likely to be favourable for the success of the new individual, and therefore, this behaviour is recognized to have adaptive value. The phytochromes are one of the most relevant photoreceptors involved in light perception by plants. We explored the redundancy and diversity functions of the phytochrome family in the control of seed responsiveness to light and gibberellins (GA) by using a set of phytochrome mutants of Arabidopsis. Our data show that, in addition to the well-known role of phyB in the promotion of germination in response to high red to far-red ratios (R/FR), phyE and phyD stimulate germination at very low R/FR ratios, probably by promoting the action of phyA. Further, we show that phyC regulates negatively the seed responsiveness to light, unravelling unexpected functions for phyC in seed germination. Finally, we find that seed responsiveness to GA is mainly controlled by phyB, with phyC, phyD and phyE having relevant roles when acting in a phyB-deficient background. Our results indicate that phytochromes have multiple and complex roles during germination depending on the active photoreceptor background.
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Arabidopsis/crescimento & desenvolvimento , Arabidopsis/genética , Germinação/efeitos da radiação , Giberelinas/farmacologia , Luz , Família Multigênica , Fitocromo/genética , Arabidopsis/efeitos dos fármacos , Arabidopsis/efeitos da radiação , Germinação/efeitos dos fármacos , Modelos Biológicos , Mutação/genética , Fitocromo/metabolismo , Sementes/efeitos dos fármacos , Sementes/crescimento & desenvolvimento , Sementes/efeitos da radiaçãoRESUMO
Two elastic systems are considered in this work: A special linear chain of harmonic oscillators and a quasi one-dimensional vibrating rod. Starting in both cases with a locally periodic system formed by unit cells with a single element, these cells are converted into binary cells. The acoustic and optical bands then appear. For the vibrating rod experimental values are compared with theoretical results; in particular, the normal-mode amplitudes are obtained and the agreement is excellent.
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We study the scattering of waves in systems with losses or gains simulated by imaginary potentials. This is done for a complex delta potential that corresponds to a spatially localized absorption or amplification. In the Argand plane the scattering matrix moves on a circle C centered on the real axis, but not at the origin, that is tangent to the unit circle. From the numerical simulations it is concluded that the distribution of the scattering matrix, when measured from the center of the circle C, agrees with the nonunitary Poisson kernel. This result is also obtained analytically by extending the analyticity condition, of unitary scattering matrices, to the no-unitary ones. We use this nonunitary Poisson kernel to obtain the distribution of nonunitary scattering matrices when measured from the origin of the Argand plane. The obtained marginal distributions have excellent agreement with the numerical results.
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Algoritmos , Transferência de Energia , Modelos Teóricos , Reologia/métodos , Simulação por ComputadorRESUMO
We derive an exact formula to calculate the absorption strength in absorbing chaotic systems such as microwave cavities or acoustic resonators. The formula allows us to estimate the absorption strength as a function of the averaged reflection coefficient and the real coupling parameter. We also define the weak and strong absorption regimes in terms of the coupling parameter and the absorption strength.
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La diabetes mellitus ocupa el sexto lugar de las defunciones por causas definidas en la provincia de Misiones. Nos propusimos establecer si existen diferencias significativas para Colesterol Total (CT), Triglicéridos (TG), Colesterol-HDL(CHDL), Colesterol-LDL(CLDL), Colesterol-IDL(CIDL), Colesterol no-HDL y los índices CT/CHDL y TG/CHDL entre diabéticos tipo 2 y un grupo control y comparar los valores de CIDL entre ambos grupos según fenotipo de dislipidemia. Se estudiaron 70 diabéticos tipo 2 (DM 2) y 57 controles. CT, TG, CHDL y CLDL se determinaron por métodos enzimáticos colorimétricos y CIDL por método de Wikinski. Los resultados obtenidos en DM 2 vs. controles fueron: CT 214±49 vs. 205±34 mg/dl (p=0.488); TG 194±119 vs. 128±65 mg/dl (p<0.001); CHDL 43±11 vs. 50±13 mg/dl (p=0.001); CLDL 135±43 vs. 132±32 mg/dl (p=0.934); CIDL 13.8±8.7 vs. 7.2±3.5 mg/dl (p<0.001); CT/CHDL 5.26±1.54 vs. 4.40±1.33 (p=0.001); TG/CHDL 5.01±3.95 vs. 2.97±2.24 (p<0.001) y Col no-HDL 172±48 vs. 155±35 mg/dl (p=0.07); a igual patrón electroforético tanto normolipémico (p=0.043), fenotipo II (p=0.006) o fenotipo IV (p=0.001) el CIDL fue más elevado en el primer grupo. La cuantificación del CIDL mejora la valoración del riesgo aterogénico en DM 2 principalmente en los normolipémicos.
Diabetes Mellitus is in the sixth death cause in the province of Misiones. Majority of patients die in relation with atherosclerosis, being dislipidemias one of the mechanism that explain this increased risk. We aimed to establish if there are significant differences for total cholesterol (TC), triglyceride (TG), HDL-cholesterol (HDLC), LDL-Cholesterol (LDLC), IDL-Cholesterol (IDLC), no-HDL Cholesterol and the index TC/HDLC and TG/HDLC between diabetic patients type 2 and a control group, as well as comparing the IDLC amount between both groups according to the dislipidemia phenotype. We studied 70 diabetic patients type 2 and 57 controls, with similar distribution in age, sex and body mass index. TC, TG, HDLC and LDLC were tested by enzymatic colorimetric methods with internal and external quality controls and the IDLC by Wikinski method. The results obtained in diabetic patients vs controls were (table N°1): TC 214 ±49 vs 205± 34 mg/dl (p=0.488); TG 194±119 vs 128±65 mg/dl (p<0.001); HDLC 43±11 vs 50±13 mg/dl(p=0.001); LDLC 135±43 vs 132± 32 mg/dl (p=0.934); IDLC 13.8± 8.7 vs 7.2±3.5 mg/dl (p<0.001) (figure N°1); TC/HDLC 5.26 ±1.54 vs 4.40± 1.33 (p=0.001); TG/HDLC 5.01±3.95 vs 2.97±2.24 (p<0.001) y no-HDL cholesterol 172±48 vs 155±35 mg/dl (p=0.07); at a same electrophoretic pattern ( normolipemic (p=0.043), phenotype II (p=0.006) or phenotype IV (p=0.001)),the IDLC was higher in the first group (figure N°2). The diabetic patients show a more atherogenic lipoprotein profile than the control group. The quantification of IDLC improvement the assessment of atherogenic risk in type 2 diabetic patients, specially normolipemics.
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The optical analogues of Bloch oscillations and their associated Wannier-Stark ladders have been recently analyzed. In this Letter we propose an elastic realization of these ladders, employing for this purpose the torsional vibrations of specially designed one-dimensional elastic systems. We have measured, for the first time, the ladder wave amplitudes, which are not directly accessible either in the quantum-mechanical or optical cases. The wave amplitudes are spatially localized and coincide rather well with theoretically predicted amplitudes. The rods we analyze can be used to localize different frequencies in different parts of the elastic systems and vice versa.
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Non-modulating is a highly reproducible type of sodium-sensitive hypertension. The aim of this study was to evaluate in non-modulating individuals the erythrocyte sodium-lithium countertransport (SLC) abnormalities, which have been mentioned as a marker of non-modulation, and the association with increased microalbuminuria, as a marker of an early kidney impairment. We measured erythrocyte SLC in 10 normotensives (NT, 28 +/- 4 years), 20 offspring of hypertensive parents being 10 modulating (MHO, 25 +/- 6 years) and 10 non-modulating (NMHO, 26 +/- 5 years), and 23 essential hypertensives being 12 modulating (MHT, 34 +/- 5 years) and 11 non-modulating (NMHT, 32 +/- 4 years). In all the subjects studied, microalbuminuria was determined by duplicate 24-h urine collection by radioimmunoassay. In non-modulating offspring of hypertensive parents and essential hypertensives. SLC was significantly elevated when compared either with normotensives without family history of hypertension, modulating offspring of hypertensive parents or essential hypertensives (P < 0.025). Likewise, 24-h urinary albumin excretion was found higher in non-modulating individuals (essential hypertensives and offspring of hypertensive parents) than in modulating individuals (P < 0.01). In conclusion, non-modulators with higher SLC countertransport sodium transport abnormalities showed higher elimination of microalbuminuria suggesting that non-modulators may have an increased risk for developing cardiovascular morbidity and kidney impairment even in normotensive subjects with familiarity history of hypertension.
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Albuminúria/complicações , Antiporters/metabolismo , Eritrócitos/metabolismo , Hipertensão/genética , Hipertensão/metabolismo , Adulto , Análise de Variância , Transporte Biológico , Feminino , Humanos , Hipertensão/complicações , Masculino , Fatores de Risco , Estatísticas não ParamétricasRESUMO
BACKGROUND: A new procedure to improve the accuracy of inulin assessment and renal glomerular filtration rate (GFR) avoiding urine sampling was compared and validated versus the reference procedure (with urine sampling and Anthrone reaction) in conscious unrestrained male Wistar rats. METHODS: The hemodynamic study consisted of a priming dose of inulin (16 mg/kg) and para-aminohippurate (PAH; 8 mg/kg) followed by an infusion of inulin (36 mg/mL) and PAH (5.8 mg/mL) at a rate of 0.055 mL/min until steady-state conditions were reached (105 min). Inulin concentrations from samples were determined by a new enzymatic assay and Anthrone reaction. PAH concentrations were determined according to the standard method described by Smith et al. RESULTS: A high correlation was found between GFR and renal blood flow (RBF) values calculated using the alternative (without urine sampling) and the reference (with urine sampling) clearance techniques (r = 0.98, P < 0.001, and r = 0.97, P < 0.001, respectively). Moreover, a significant and positive correlation between the values obtained from enzymatic and Anthrone inulin assessments was found (r = 0.99, P < 0.001). Likewise, the values of the 95% confidence interval (mean +/- 2 SD) for the enzymatic inulin assay showed a good agreement with those achieved with Anthrone (1.14 +/- 0.21 and 1.14 +/- 0.19 mL. min-1. 100 g-1 rat body weight, respectively). CONCLUSIONS: This new approach has methodological and experimental advantages with respect to traditional procedures, making it a useful tool, not only for research purposes but also in the clinical setting.
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Taxa de Filtração Glomerular , Inulina , Circulação Renal , Ácido p-Aminoipúrico , Animais , Inulina/farmacocinética , Nefropatias/diagnóstico , Modelos Lineares , Masculino , Ratos , Ratos Wistar , Sensibilidade e Especificidade , Urina , Ácido p-Aminoipúrico/farmacocinéticaRESUMO
Seed germination is often induced by a pulse of red light perceived by phytochrome and cancelled by a subsequent pulse of far-red light. When the pulse of red light is followed by several hours of darkness, a pulse of far-red light is no longer effective and prolonged far-red is necessary to block germination. The aim was to investigate whether the red light pulse and prolonged far-red light act on the same or different processes during germination of Datura ferox seeds. Forty-five hours after the inductive red light pulse, germination could not be blocked by one pulse or six hourly pulses of far-red light, but was significantly reduced by 6 h of continuous far-red light. The pulse of red light increased embryo growth potential and the activities of beta-mannanase and beta-mannosidase extracted from the micropylar region of the endosperm. Continuous far-red light had no effect on embryo growth potential or beta-mannosidase activity, but severely reduced the activity of beta-mannanase. The effect of far-red light had the features of a high-irradiance response of phytochrome. Both germination and beta-mannanase activity were restored by a pulse of red light given after the end of the continuous far-red treatment. It is concluded that the low-fluence response and the high-irradiance response modes of phytochrome have antagonistic effects on seed germination and that the control of beta-mannanase activity is one process where this antagonism is established.
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Datura stramonium/efeitos da radiação , Germinação/efeitos da radiação , Luz , Manosidases/metabolismo , Fitocromo/fisiologia , Plantas Medicinais , Plantas Tóxicas , Sementes/efeitos da radiação , Datura stramonium/crescimento & desenvolvimento , Datura stramonium/metabolismo , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , beta-ManosidaseRESUMO
Current evidence is inconclusive regarding the point of signaling convergence downstream from different members of the phytochrome family. In transgenic Arabidopsis, the activity of a reporter enzyme under the control of the -453 to +67 fragment of an Lhcb1*2 promoter shows very low fluence responses (VLFRs) and high-irradiance responses (HIRs) mediated by phytochrome A and low-fluence responses (LFRs) mediated by phytochrome B. A 5' deletion of the promoter to -134 abolished the HIR without affecting VLFR or LFR. In transgenic tobacco, VLFR and LFR were observed for the -176 to -31 or -134 to -31 fragments of Lhcb1*2 fused to 35S cauliflower mosaic virus minimal promoters, but only the largest fragment showed HIR. We propose that sustained activation of phytochrome A with far-red light initiates a signaling cascade that deviates from phytochrome B signaling and transient phytochrome A signaling and that this divergence extends as far as the Lhcb1*2 promoter.
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Células Fotorreceptoras , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Fitocromo/metabolismo , Regiões Promotoras Genéticas , Transdução de Sinais , Fatores de Transcrição , Arabidopsis/metabolismo , Proteínas de Arabidopsis , Sequência de Bases , Caulimovirus/genética , Primers do DNA , Fitocromo A , Fitocromo B , Plantas Geneticamente ModificadasRESUMO
El pseudoquiste del pancreas es una entidad de cierta presentacion en la práctica clinica, generalmente secundaria a un proceso inflamatorio o al trauma pancreático. Su tratamiento se realiza mediante puncion o con derivaciones entre la pared del quiste y una viscera adyacente como estomago, duodeno o yeyuno. Estas derivaciones se pueden realizar por tecnica convencional abierta, por via endoscopica y por via laparoscopica ultimamente descrita. Se presenta la tecnica de Cistoyeyunostomia via laparoscopica sin necesidad de realizar una Y de Roux, llevada a cabo en 3 pacientes durante los años 1998-1999, sin tener complicacion alguna, y con seguimiento a 2 años en el primero de los casos. Se concluye que la Cistoyeyunostomia via laparoscópica es una alternativa fácil y con las ventajas que representa la cirugia minimamente invasora.
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Laparoscopia , Cisto Pancreático/cirurgia , JejunostomiaRESUMO
The authors interviewed an age- and occupation-stratified sample of 466 women, aged 18-40, from 12 Tijuana neighborhoods, about sociodemographic characteristics, work and reproductive history, and musculoskeletal complaints. A total of 29.8% reported experiencing aches or pain in the low back, 38.3% in the upper back, 26.4% in the neck/shoulders, 18.2% in the hand/wrist, and 28.3% in the legs in the preceding year. Both sociodemographic and occupational factors were associated with these complaints. Very low educational attainment, having substandard housing, being the head of household, and being a migrant were each associated with an increased prevalence of one or more musculoskeletal complaints. In general, working outside the home increased the risk of musculoskeletal complaints. Compared with women who had not worked in the preceding 30-month period, those working in the maquiladora had 40-90% higher risks of upper back, neck/shoulder, and hand/wrist pain. Compared with women working outside the maquiladora, maquiladora women workers had 20% higher risks of low back, upper back, and neck/shoulder complaints. More detailed studies of the incidences of musculoskeletal disorders and of specific etiologic risk factors within the maquiladora industry are warranted. Future studies should concurrently evaluate sociodemographic risk factors.
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Doenças Musculoesqueléticas/epidemiologia , Adolescente , Adulto , Dor nas Costas/epidemiologia , Estudos Transversais , Feminino , Humanos , México/epidemiologia , Cervicalgia/epidemiologia , Projetos Piloto , Fatores de Risco , Dor de Ombro/epidemiologia , Fatores SocioeconômicosRESUMO
Non-modulators are a subset of essential hypertensive individuals in whom renal hemodynamic and adrenal aldosterone responses to angiotensin II fail to modulate appropriately during high dietary salt intake. The main aim of this study was to investigate the familial aggregation of non-modulation and several erythrocyte Na+ transport systems in normotensive and hypertensive individuals as well as offspring of hypertensive parents. An additional aim was to evaluate the effect of treatment with enalapril on erythrocyte Na+ transport. We studied 15 normotensive subjects (6 males, 27+/-6 years), 14 untreated modulating essential hypertensive subjects (7 males, 38+/-7 years), 12 untreated non-modulating essential hypertensive subjects (7 males, 38+/-6 years), 14 modulating offspring of hypertensive parents (8 males, 25+/-6 years), and 14 non-modulating offspring of hypertensive parents (8 males, 26+/-4 years). Blood pressure was recorded with an oscillometric device and renal plasma flow and glomerular filtration rate by clearances of para-aminohippurate and inulin, respectively. Non-modulating subjects were identified as individuals who failed to increase effective renal plasma flow by 30% and decrease filtration fraction by at least 30% 10 days after changing from a low (20 mmol/d) to a high (250 mmol/d) sodium intake. Erythrocyte Na+ transport was characterized by measurements of the Na+-K+ pump, Na+-Li+ countertransport, Na+-K+-Cl- cotransport, passive Na+ permeability, and Na+ content. After the initial studies, hypertensive individuals were treated with enalapril (20 mg/d P.O.) for 6 months, after which erythrocyte Na+ transport measurements were again made. The main findings were that Na+-Li+ countertransport is increased in non-modulating hypertensive subjects and non-modulating offspring of hypertensive parents, that the increase in blood pressure in response to high salt intake is greater in non-modulating than modulating hypertensive subjects, and that enalapril decreases Na+-Li+ countertransport activity to normal in non-modulating hypertensive subjects. These findings provide support for a possible genetic role in the development of salt sensitivity and suggest that Na+-Li+ countertransport and non-modulation are related phenotypes.
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Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Anti-Hipertensivos/uso terapêutico , Enalapril/uso terapêutico , Eritrócitos/metabolismo , Hipertensão/tratamento farmacológico , Hipertensão/genética , Lítio/sangue , Sódio/sangue , Adulto , Inibidores da Enzima Conversora de Angiotensina/administração & dosagem , Anti-Hipertensivos/administração & dosagem , Transporte Biológico , Cloretos/metabolismo , Interpretação Estatística de Dados , Enalapril/administração & dosagem , Feminino , Humanos , Hipertensão/metabolismo , Lítio/análise , Masculino , Pessoa de Meia-Idade , Sódio/análise , Sódio/metabolismo , Sódio na Dieta/efeitos adversos , ATPase Trocadora de Sódio-Potássio/metabolismo , Espectrofotometria Atômica , Fatores de TempoRESUMO
The occurrence of very-low-fluence responses (VLFR), low-fluence responses (LFR) and high-irradiance responses (HIR) of phytochrome was investigated for the expression of the gene of beta-glucuronidase (gusA) under the control of the tobacco Lhcb1*2 promoter, in etiolated transgenic tobacco seedlings. The activity of beta-glucuronidase (GUS) showed biphasic responses to the calculated proportion of Pfr provided by light pulses. The first phase (i.e. the VLFR) showed a maximum for Pfr levels characteristic of far-red light. The second phase (i.e. the LFR) was observed at higher Pfr levels and was reversible by far-red light pulses. The strong effect of continuous far-red light (i.e. HIR) was fluence-rate-dependent and could not be replaced either by hourly pulses of the same spectral composition and total fluence or by very low fluences of red light. Deletion of the Lhcb1*2 promoter to -453 caused little loss of GUS activity. The -453 to -31, -270 to -31 and -176 to -31 fragments of the Lhcb1*2 promoter conferred proportionally normal VLFR, LFR and HIR to a truncated (-46 to +8) CaMV 35S minimal promoter. This is the first demonstration of the presence of three phytochrome action modes in the control of the transcriptional activity of a single gene. The cis-acting regulatory elements necessary for VLFR, LFR and HIR are present in a 146 bp fragment of the tobacco Lhcb1*2 promoter.
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Caulimovirus/genética , Nicotiana/fisiologia , Fitocromo/fisiologia , Plantas Tóxicas , Regiões Promotoras Genéticas , Sequência de Bases , Expressão Gênica/efeitos da radiação , Glucuronidase/biossíntese , Cinética , Luz , Dados de Sequência Molecular , Fitocromo/efeitos da radiação , Regiões Promotoras Genéticas/genética , Proteínas Recombinantes de Fusão/biossíntese , Nicotiana/genéticaRESUMO
Knowledge about the viscoelastic behaviour of the arterial wall has been proved to have physiological importance and clinical usage. Our purpose was to study the changes of the systemic arterial wall's elastic properties non-invasively, in patients with established essential and with borderline hypertension, and to evaluate its possible determinants. Three groups of normotensive, borderline and established essential hypertensive patients were evaluated. Arterial pulse wave velocity (PWV) was measured and arterial compliance (Cm) was derived in all patients. Pulse wave velocity was obtained from the pressure values of digitized carotid and radial arteries. Arterial compliance (Cm = dD/dP with P pressure and D diameter) was calculated using a formula derived from the Bramwell and Hill equation: Cm = (1,334 x D)/(2 rho x PWV2), where for D humeral diameter was used as measured by high resolution echograph, and rho is the blood density (rho = 1.06). Pulse wave velocity was significantly higher in established essential hypertensive patients with respect to normotensive patients (p < 0.05). Arterial compliance was significantly diminished in established and in borderline hypertensive patients with respect to normotensive patients (p < 0.05), which implies early alterations in hypertensive cardiovascular disease. Multiple regression analysis of the cofactors showed that age and diastolic pressure are independent determinants of Cm. Impairment of the arterial wall's intrinsic elastic properties was demonstrated in established essential hypertension, independent of age and diastolic pressure.
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Artérias/fisiopatologia , Hipertensão/fisiopatologia , Adolescente , Adulto , Fatores Etários , Idoso , Algoritmos , Artérias/diagnóstico por imagem , Artérias/patologia , Velocidade do Fluxo Sanguíneo/fisiologia , Pressão Sanguínea/fisiologia , Viscosidade Sanguínea/fisiologia , Artéria Carótida Primitiva/diagnóstico por imagem , Artéria Carótida Primitiva/patologia , Artéria Carótida Primitiva/fisiopatologia , Diástole , Elasticidade , Feminino , Frequência Cardíaca/fisiologia , Humanos , Úmero/irrigação sanguínea , Úmero/diagnóstico por imagem , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Fluxo Pulsátil/fisiologia , Artéria Radial/diagnóstico por imagem , Artéria Radial/patologia , Artéria Radial/fisiopatologia , Ultrassonografia , Capacitância Vascular/fisiologia , ViscosidadeRESUMO
The role of abscisic acid (ABA) and gibberellic acid (GA) in determining the dormancy level of developing sorghum (Sorghum bicolor [L.] Moench.) seeds from varieties presenting contrasting preharvest sprouting behavior (Redland B2, susceptible; IS 9530, resistant) was investigated. Panicles from both varieties were sprayed soon after pollination with fluridone or paclobutrazol to inhibit ABA and GA synthesis, respectively. Fluridone application to the panicles increased germinability of Redland B2 immature caryopses, whereas early treatment with paclobutrazol completely inhibited germination of this variety during most of the developmental period. Incubating caryopses in the presence of 100 [mu]M GA4+7 overcame the inhibitory effect of paclobutrazol, but also stimulated germination of seeds from other treatments. IS 9530 caryopses presented germination indices close to zero until physiological maturity (44 d after pollination) in control and paclobutrazol-treated particles. However, fluridone-treated caryopses were released from dormancy earlier than control and paclobutrazol-treated caryopses. Incubation in the presence of GA4+7 stimulated germination of caryopses from all treatments. Our results support the proposition that a low dormancy level (which is related to a high preharvest sprouting susceptibility) is determined not only by a low embryonic sensitivity to ABA, but also by a high GA content or sensitivity.