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1.
Pak J Biol Sci ; 12(5): 406-12, 2009 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-19579979

RESUMO

The effect of salinity on morphological characters of salt tolerant genotypes PVSB9, PVSB19, PNR381, PNR519, Iratom24 and salt sensitive genotype NS15 along with one standard check salt tolerant rice cultivar Pokkali were assessed in two factors Completely Randomized Design with four replications. Seven rice genotypes in combination with six levels of salinity (0, 3, 6, 9, 12 and 15 dS m(-1)) were randomly assigned in 168 experimental plastic pots. The different morphological characters studied include plant height, total number of tillers, Root Dry Weight (RDW), Shoot Dry Weight (SDW) and Total Dry Matter (TDM) content of the selected rice genotypes in view to evaluate their response at different salinity levels. The results on the effect of morphological characters indicated that plant height, total tillers, root, shoot and total dry matter were significantly decreased by the application of salinity. The genotypes Pokkali, PVSB9, PVSB19 showed significantly higher values and the lowest value of all these characters were recorded in NS15. A sharp decrease in percent relative-plant height, RDW, SDW, TDM, total tillers were found in susceptible genotype NS 15 after 3 dS m(-1) level of salinity, but these characters were found to decrease slowly in tolerant genotypes.


Assuntos
Oryza/genética , Oryza/fisiologia , Tolerância ao Sal/genética , Genótipo , Oryza/anatomia & histologia , Raízes de Plantas/anatomia & histologia , Brotos de Planta/anatomia & histologia , Distribuição Aleatória , Salinidade
2.
Int J Artif Organs ; 24(12): 870-7, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11831592

RESUMO

Biological valves display a dependence of valve resistance and valve area on flow and a phase shift between systolic flow through the valves and pressure difference across the valves. The pressure-flow relations of stenosed valves raise questions about the "best measure of stenosis". There is a need for quantitative evaluation of the hydrodynamic performance of homografts and allografts. In the present paper, we report on in vitro studies of the hydrodynamic behavior of homografts from human donors, allografts from different animal species as well as three valve models. Valve model I was designed to simulate flow-dependence of valve area, valve model II was designed to simulate restricted valve opening independent of flow, and valve model III was designed to simulate a flow-dependent movement of valve root in flow direction. Among other aspects, the effect of increased viscosity of the test fluid on the pressure difference and the effects of water absorption by valve tissue on valve characteristics were investigated. The results of the present studies clearly indicate that any biological valve may be modelled as a serial connection of a model I type valve and a model II type valve. From the results, the dependence of the characteristic pressure-flow relationship of a valve on valve size and valve distensibility can be clearly seen and the clinical significance of the characteristic coefficients of the pressure-flow relationship of a valve can be elucidated. Further, it was shown that the characteristic phase shift between flow and pressure difference displayed by biological valves is due to their movable valve plane similar to that of valve model III.


Assuntos
Estenose da Valva Aórtica/cirurgia , Próteses Valvulares Cardíacas , Animais , Estenose da Valva Aórtica/fisiopatologia , Velocidade do Fluxo Sanguíneo , Modelos Cardiovasculares , Modelos Estruturais , Fluxo Pulsátil/fisiologia , Sensibilidade e Especificidade , Suínos , Transplante Homólogo
3.
J Invest Surg ; 10(5): 281-6, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9361992

RESUMO

A device designed specifically for mild to severe concussions was used to produce quantitative experimental blunt brain injury in male Wistar rats. We have examined the effects of varying magnitudes of cerebral trauma on the maximal binding capacity (Bmax) of D1 and D2 dopamine (DA) receptors. The Bmax for each receptor subtype was obtained from Scatchard analyses of [3H]-SCH 23390 and [3H]Spiperone binding to striatal membrane. Anesthetized rats were injured--one, two, or three times--once every 24 h, with either a 68- or 268-g rubber-headed reflex hammer accelerated from a predetermined distance. Uninjured nonanesthetized (NA) and anesthetized (A) rats served as controls. No significant difference in receptor density was observed between NA and A rats for each receptor subtype. Immediately (0 h) following injury from the 68-g hammer weight, the density of D1 receptors decreased (50%), then increased (30%) above control levels by 24 h. The same pattern was observed with the 268-g hammer weight. Analysis of variance (ANOVA) showed that there was no overall effect of number of injuries or treatment on the density of D1 and D2 receptor subtypes. However, there was an interaction of both variables on the D1, but not D2, receptor subtype. Partial ANOVA for receptor densities after rats were injured either one, two, or three times showed that receptor density was altered only after the rats were injured one time. These results suggest that striatal DA D1 receptors are downregulated and then upregulated following isolated injury to the cerebral cortex.


Assuntos
Lesões Encefálicas/metabolismo , Corpo Estriado/química , Receptores de Dopamina D1/análise , Receptores de Dopamina D2/análise , Ferimentos não Penetrantes/metabolismo , Animais , Benzazepinas/metabolismo , Masculino , Ratos , Ratos Wistar , Espiperona/metabolismo
4.
Vopr Onkol ; 36(8): 935-40, 1990.
Artigo em Russo | MEDLINE | ID: mdl-2219834

RESUMO

Method of immunodiffusion titration of rabbit monospecific antiserum (The I. M. Mechnikov Central Research Institute of Vaccines and Sera of the USSR Ministry of Health) in agar was used to measure blood C-reactive protein (C-RP) level in patients with acute pneumonia (32), protracted pneumonia or activation of chronic non-specific lung pathology (101) and lung cancer (153) after a 3-4-week course of complex antiinflammatory treatment and a 10-14-day course of immunostimulation with pyrogenal (The N. F. Gamaleya Research Institute of Epidemiology and Microbiology). A decrease in the incidence (from 81.2% to 14.2%) and level (from 1.4 +/- 0.3 to 0.3 +/- 0.03 mg%) of C-RP was observed in cases of non-tumor pathology whereas in patients with lung cancer those values rose in step with tumor progression (from 72.2% and 0.4 +/- 0.07 mg% at stage I to 96.3% and 1.2 +/- 0.12 mg% at stage IV). Treatment with pyrogenal allowed to identify C-RP in patients with false-negative reaction in all subgroups. Two-week dynamic C-RP curves characterizing non-tumor and tumor pathology of the lung were plotted.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Proteína C-Reativa/biossíntese , Lipopolissacarídeos/uso terapêutico , Pneumopatias Obstrutivas/terapia , Neoplasias Pulmonares/terapia , Pneumonia/terapia , Feminino , Humanos , Imunoterapia , Pneumopatias Obstrutivas/tratamento farmacológico , Neoplasias Pulmonares/tratamento farmacológico , Masculino , Pneumonia/tratamento farmacológico , Estimulação Química
5.
J Biomech Eng ; 108(3): 259-65, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2943939

RESUMO

Blood flow velocity was measured in the dog aorta distal to mechanically induced constrictions of various degrees of severity employing an 8-MHz pulsed Doppler ultrasound velocimeter and a phase-lock loop frequency tracking method for extracting velocity from the Doppler quadrature signals. The data were analyzed to construct ensemble average velocity waveforms and random velocity disturbances. In any individual animal the effect of increasing the degree of stenosis beyond approximately 25 percent area reduction was to produce increasing levels of random velocity disturbance. However, variability among animals was such that the sensitivity of random behavior to the degree of stenosis was degraded to the point that it appears difficult to employ Doppler ultrasound measurements of random disturbances to discriminate among stenoses with area reductions less than approximately 75 percent. On the other hand, coherent vortex structures in velocity waveforms consistently occurred distal to mild constrictions (25-50 percent area reduction). Comparison of the phase-lock loop Doppler ultrasound data with simultaneous measurements using invasive hot-film anemometry, which possesses excellent frequency response, demonstrates that the ultrasound method can reliably detect those flow phenomena in such cases. Thus, the identification of coherent, rather than random, flow disturbances may offer improved diagnostic capability for noninvasively detecting arteriosclerotic plaques at relatively early stages of development.


Assuntos
Estenose da Valva Aórtica/fisiopatologia , Velocidade do Fluxo Sanguíneo , Animais , Cães , Reologia
7.
J Thorac Cardiovasc Surg ; 73(3): 458-69, 1977 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-839836

RESUMO

The hemodynamic effects of multiple noncritical lesions in series were studied in in vitro experiments and in 15 animals. Flow visualization studies were also carried out to obtain insight into the flow pattern in the region of stenosis. Symmetrical stenosis pieces with a 50 per cent reduction in area were placed inside a plexiglass tube and used for both in vitro and in vivo experiments. Varying the number of stenoses and the spacing between them enabled us to study twelve different stenosis configurations during both pulsatile and steady flow. Flow conditions encountered clinically were simulated by varying the average Reynolds number between 30 and 380. Pressure drops across the stenosis test section were measured with a differential pressure transducer and used to calculate critical values for multiple, uniform, noncritical stenoses and for combinations of stenoses of different degrees. Results from steady and pulsatile flow in vitro were comparable, as were those results from the in vivo experiments. The pressure drop across a series of noncritical stenoses was nearly the sum of the individual pressure drops, with only slight dependence upon the spacing between stenoses, Thus it is concluded, from both experimental results and from the theoretical calculations, that the total effect of a series of noncritical stenoses may become critical and produce symptoms of arterial insufficiency.


Assuntos
Arteriopatias Oclusivas/complicações , Extremidades/irrigação sanguínea , Isquemia/etiologia , Animais , Modelos Animais de Doenças , Cães , Hemodinâmica , Modelos Biológicos , Fluxo Sanguíneo Regional
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