RESUMO
In this work the skin coating of some vertebrate marine animals is modeled considering only dermis, epidermis and basal layers. The biological process takes into account: cellular diffusion of the epidermis, diffusion inhibition and long-range spatial interaction (nonlocal effect on diffusive dispersal) for cells of dermal tissue. The chemical and physical interactions between dermis and epidermis are represented by coupling quadratic terms and nonlinear terms additional. The model presents an interesting property associated with their gradient form: a connection between some physical, chemical and biological systems. The model equations proposed are solved with numerical methods to study the spatially stable emergent configurations. The spatiotemporal dynamic obtained of the numerical solution of these equations, present similarity with biological behaviors that have been found recently in the cellular movement of chromatophores (as contact-dependent depolarization and repulsion movement between melanophores, xanthophores and iridophores). The numerical solution of the model shows a great variety of beautiful patterns that are robust to changes of boundary condition. The resultant patterns are very similar to the pigmentation of some fish.
Assuntos
Peixes/anatomia & histologia , Modelos Biológicos , Pigmentação da Pele , Algoritmos , Animais , Comunicação Celular/fisiologia , Cromatóforos/fisiologia , Células Epidérmicas , Células Epiteliais/fisiologia , Mecanotransdução Celular/fisiologia , Pele/citologiaRESUMO
The atmospheres of the gas giant planets (Jupiter and Saturn) contain jets that dominate the circulation at visible levels. The power source for these jets (solar radiation, internal heat, or both) and their vertical structure below the upper cloud are major open questions in the atmospheric circulation and meteorology of giant planets. Several observations and in situ measurements found intense winds at a depth of 24 bar, and have been interpreted as supporting an internal heat source. This issue remains controversial, in part because of effects from the local meteorology. Here we report observations and modelling of two plumes in Jupiter's atmosphere that erupted at the same latitude as the strongest jet (23 degrees N). The plumes reached a height of 30 km above the surrounding clouds, moved faster than any other feature (169 m s(-1)), and left in their wake a turbulent planetary-scale disturbance containing red aerosols. On the basis of dynamical modelling, we conclude that the data are consistent only with a wind that extends well below the level where solar radiation is deposited.
RESUMO
Saturn has an intense and broad eastward equatorial jet with a complex three-dimensional structure mixed with time variability. The equatorial region experiences strong seasonal insolation variations enhanced by ring shadowing, and three of the six known giant planetary-scale storms have developed in it. These factors make Saturn's equator a natural laboratory to test models of jets in giant planets. Here we report on a bright equatorial atmospheric feature imaged in 2015 that moved steadily at a high speed of 450 ms-1 not measured since 1980-1981 with other equatorial clouds moving within an ample range of velocities. Radiative transfer models show that these motions occur at three altitude levels within the upper haze and clouds. We find that the peak of the jet (latitudes 10° N to 10° S) suffers intense vertical shears reaching +2.5 ms-1 km-1, two orders of magnitude higher than meridional shears, and temporal variability above 1 bar altitude level.
RESUMO
BACKGROUND: The elevated incidence of malnutrition in the elderly and its close relation with the prevalence and evolution of determined diseases raises the need for early identification. Despite the existence of numerous indicators, specificity, sensitivity or occasionally both are lacking. METHODS: One hundred fifteen institutionalized elderly of which 19 females and 12 males had signs of malnutrition were studied. A dietetic survey was carried out on all of those studied by means of a 24 hour recollection-interview, during which triceps fold (TF) and muscular area of the arm (MAA) were measured and serum concentrations of prealbumin (PA) protein bound to retinol (PBR), albumin (ALB), trasferrin (TNF) and complement factor 3 (C3) were determined. RESULTS: Not only caloric but also proteic intake were significantly lower in the undernourished (p less than 0.001) as with ALB (p less than 0.001), TNF (p less than 0.001) and C3 (p less than 0.02 in males and p less than 0.05 in females). However, the sensitivity demonstrated by the dietetic survey (77% in males and 73% in females) was higher to that presented by ALB (44% in males and 53% in females), TNF (33% in males and 53% in females) and C3 (0 in both sexes). CONCLUSIONS: The results obtained demonstrate that the dietetic survey is a valid method for detecting not only the risk but also the subclinical presence of malnutrition, in contrast to ALB, TNF and C3 which, to that end, were of less use.
Assuntos
Inquéritos sobre Dietas , Distúrbios Nutricionais/epidemiologia , Fatores Etários , Idoso , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Humanos , Distúrbios Nutricionais/sangue , Distúrbios Nutricionais/diagnóstico , Estado Nutricional , Fatores Sexuais , Espanha/epidemiologia , Fatores de TempoRESUMO
We studied the role played by an adequate metabolic control on lipids, lipoproteins, apolipoprotein A (apo A), apolipoprotein A-I (apo A-I) and apolipoprotein B (apo B), in 30 type I diabetic patients at different states of the diseases. We did not observe significant differences, comparing the mean values of lipids and lipoproteins, in the group of patients with good metabolic control. Patients, without appropriate diabetic control, showed values significantly higher in triglycerides and VLDL-C and significantly lower in HDL-C compared to the values of the control group. In respect of the apoprotein pattern, we did not observe significant differences between controlled diabetic patients; while non-controlled diabetic patients showed mean values higher of apo B, but no differences between apo A and apo A-I. Our results support the previous evidence published by other authors, confirming the relationship between an adequate diabetic control and the onset of lipoprotein changes, that can play a causal role in arteriosclerosis.
Assuntos
Apoproteínas/sangue , Diabetes Mellitus Tipo 1/sangue , Lipídeos/sangue , Lipoproteínas/sangue , Adolescente , Adulto , Glicemia/metabolismo , Criança , Feminino , Humanos , MasculinoRESUMO
The effects of the inhalation of 2.2 mg of nicotine in 20 persons with normal blood pressure and heavy smokers were studied. Blood pressure, heart rate, plasmatic renin activity, aldosterone and angiotensin-converting enzyme (ACE) changes were registered 10 and 20 minutes after the inhalation. Systolic and diastolic blood pressure increased significantly, as well as heart rate. Although the plasmatic renin activity did not alter during the study, aldosterone and the ACE activity increased significantly, being undoubtedly correlated. part from the adrenergic response and the possible effects of ACTH on aldosterone, secondary to nicotine, the results showed a possible modification of the renin-angiotensin-aldosterone, directly related to tobacco inhalation.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Nicotiana , Peptidil Dipeptidase A/efeitos dos fármacos , Plantas Tóxicas , Fumaça/efeitos adversos , Adulto , Feminino , Humanos , Masculino , Nicotina/efeitos adversos , Peptidil Dipeptidase A/sangue , Sistema Renina-Angiotensina/efeitos dos fármacos , Fumar/efeitos adversos , Fumar/sangue , Fatores de TempoRESUMO
42 persons with normal blood pressure were studied. Only 31 of them were smokers. We did not find any differences in the basal blood pressure, heart rate, ACTH nor cortisol levels, but there were significant differences in the levels of biological markers of tobacco (cotinine and nicotine). When the smokers were induced to smoke 2 cigarettes which had 2.2 mg of nicotine, we observed an increase in the diastolic and systolic blood pressure as well as the heart rate, plasma levels of ACTH (basal: 21.61 +/- 12.52, 10 minutes: 28.06 +/- 21.01, p less than 0.05; 20 minutes: 26.06 +/- 18.56 ng/ml) and cortisol (basal: 14.56 +/- 3.84; 10 minutes: 14.60 +/- 4.7; 20 minutes: 16.55 +/- 6.61 ug/dl, p less than 0.01). At the same time, the nicotine and cotinine levels were significantly higher (p less than 0.0001) and correlated. Our results suggest that apart from the adrenergic response to tobacco exposure, nicotine can produce other hormonal changes which affect the regulating systems of blood pressure. Nicotine and cotinine are the election biological markers to monitor the response to passive or active tobacco smoke inhalation.
Assuntos
Pressão Sanguínea/efeitos dos fármacos , Nicotiana , Nicotina/efeitos adversos , Plantas Tóxicas , Fumaça/efeitos adversos , Hormônio Adrenocorticotrópico/sangue , Adulto , Cotinina/sangue , Feminino , Humanos , Hidrocortisona/sangue , Masculino , Nicotina/sangue , Valores de Referência , Fumar/efeitos adversos , Fumar/sangueRESUMO
The changes produced by administering a calcium channel antagonist on the releasing of growth hormone (GH) induced by the growth hormone-releasing factor (GHRF), are studied. The study was performed on 7 healthy males between 25 and 35 years old, fasting and in bed. We measured the release of GH after the intravenous administration of 250 micrograms of GHRF on 2 successive occasions; one baseline and the second after 3 previous continuous days of 240 mg/day of verapamil. There were no statistically significant differences between the basal concentrations of GH before and after the administration of verapamil. However, the response of GH to GHRF, measured as maximum increase (before verapamil: 12.5 +/- 5.3; after verapamil: 9.5 +/- 3.9 ng/ml and total increase (before verapamil: 29.6 +/- 12.4; after verapamil: 21.6 +/- 11.9 ng/ml) was significantly lower after verapamil produces a partial blockade of GH release induced by GHRF.
Assuntos
Hormônio Liberador de Hormônio do Crescimento/farmacologia , Hormônio do Crescimento/antagonistas & inibidores , Verapamil/farmacologia , Adulto , Depressão Química , Hormônio do Crescimento/sangue , Humanos , Masculino , Valores de Referência , Fatores de TempoRESUMO
The aim of this study is to prove the existence of a major tendency of platelet aggregation in elderly patients compared to medium-aged adults and, also, to detect whether it is affected by the presence of diabetes mellitus. Plasmatic concentrations of B2 thromboxane (TXB2) and antithrombin III (AT III) were determined in 73 elderly patients of both sexes; 56 without metabolic disease known (Group a) and 17 diabetic patients, 7 type I (Group bI) and 10 of type II (Group bII); and 12 healthy adults (control group). Medium plasmatic concentration of TXB2 was significantly higher (p less than 0.001) in Group a (55 +/- 14 ng/ml) compared to the control group (37 +/- 9 ng/ml) and there was no difference between Group bI (53 +/- 19 ng/ml) and bII (57 +/- 15 ng/ml). No variations were noted in ATIII concentration between the adults (27.4 +/- 2.3 mg/dl) and elderly patients (a = 29.6 +/- 4.4, bI = 29 +/- 2.6, bII = 31.2 +/- 5.9 mg/dl). In elderly patients, there appears to be a state of platelet pro-aggregation without influence of any risk factor, such as diabetes. This could explain the thrombogenic tendency of this age group.
Assuntos
Antitrombina III/análise , Tromboxano B2/sangue , Idoso , Feminino , Humanos , Masculino , Agregação Plaquetária , Trombose/sangueAssuntos
Cotinina/sangue , Nicotina/sangue , Fumar/sangue , Adulto , Biomarcadores/sangue , Feminino , Humanos , MasculinoRESUMO
The atmospheres of the giant planets Jupiter and Saturn have a puzzling system of zonal (east-west) winds alternating in latitude, with the broad and intense equatorial jets on Saturn having been observed previously to reach a velocity of about 470 m x s(-1) at cloud level. Globally, the location and intensity of Jupiter's jets are stable in time to within about ten per cent, but little is known about the stability of Saturn's jet system. The long-term behaviour of these winds is an important discriminator between models for giant-planet circulations. Here we report that Saturn's winds show a large drop in the velocity of the equatorial jet of about 200 m x s(-1) from 1996 to 2002. By contrast, the other measured jets (primarily in the southern hemisphere) appear stable when compared to the Voyager wind profile of 1980-81.
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A patient suffering Cushing disease is presented in whom the administration of ciproheptadine, bromocriptine and sodium valproate in a single dose did not manage to control the clinical-biologic manifestations of the process. Combined treatment with 1.200 mg/day of sodium valproate and 15 mg/day of bromocriptine induced a complete clinical-biological remission, being arterial pressure the last parameter to normalize. The patient who has always refused to undergo surgery has stayed with this treatment for three years, maintaining remission and without appearance of side effects. On two occasions (after one and a half years and after two and half years) the transitory interruption of treatment induced in a few weeks an increase in plasma cortisol levels which again normalized after treatment was re-established. There were no clinical-biological data, pharmacological tests which permitted the prediction of these therapeutic results and therefore, the therapeutic response obtained is not indicative of any specific etiological subtype of Cushing disease.
Assuntos
Bromocriptina/uso terapêutico , Síndrome de Cushing/tratamento farmacológico , Ácido Valproico/uso terapêutico , Doença Crônica , Ciproeptadina/uso terapêutico , Quimioterapia Combinada , Feminino , Humanos , Pessoa de Meia-Idade , Indução de Remissão , Fatores de TempoRESUMO
In order to evaluate whether plasma beta-thromboglobulin (as a marker of the degree of platelet function) in patients presenting clinically evident atherosclerosis is related to the presence or absence of different risk factors (smoking habit, arterial hypertension, hypercholesterolemia, diabetes, hypertriglyceridemia, obesity, hyperuricemia, alcoholism), 40 patients have been studied in whom mean beta-thromboglobulin levels was 54 +/- 25.56 ng/ml, which is very superior to levels considered normal. However, the presence of one or more risk factors did not lead to significant variations in b-thromboglobulin concentrations, and no differences were found either when each risk factor was considered separately. The positive correlation (r = 0.98; p less than 0.01) between beta-thromboglobulin and apo B levels is highlighted. The results suggest that platelet hyperfunction seems to be due to a greater extent to the atherosclerotic process rather than to the existence of a particular risk factor.
Assuntos
Arteriosclerose/sangue , beta-Tromboglobulina/análise , Idoso , Alcoolismo/complicações , Apolipoproteínas B/sangue , Arteriosclerose/etiologia , Complicações do Diabetes , Feminino , Humanos , Hipertensão/complicações , Lipídeos/sangue , Masculino , Obesidade/complicações , Fatores de Risco , Fumar , Ácido Úrico/sangueRESUMO
Effects of calorie/protein malnourishment have been studied on plasma concentrations of cholesterol, triglycerides, HDL-C, LDL-C and apolipoproteins A and B, in institutionalized elderly people, 53 males and 62 females, of whom 19 females and 12 males were malnourished. In malnourished patients, total cholesterol and LDL-C were significantly lower both in males and in females, but HDL-C was lower only in females. No significant differences in plasma triglycerides were found between the control and the malnourished groups. Apolipoprotein A showed no significant changes on malnourished males, but did show a significant lowering in malnourished females. On the opposite, apolipoprotein B was lower in males than in females. The lowering in cholesterol in malnourished patients leads us to think that this could be a early predictor of nutritional risk in the elderly.
Assuntos
Apolipoproteínas A/análise , Apolipoproteínas B/sangue , Colesterol/sangue , Desnutrição Proteico-Calórica/sangue , Triglicerídeos/sangue , Idoso , Idoso de 80 Anos ou mais , Biomarcadores , Feminino , Humanos , Masculino , Fatores SexuaisRESUMO
In order to investigate the mechanisms by which gastrin cause GH release in humans we measured the GH response to pentagastrin alone (1.5 micrograms/kg/hour from 120 to 210 min) and following pretreatment with GHRH (GHRH 1-29,250 micrograms, iv at 0 min) in normal male subjects. Prior GHRH administration abolished the GH response to the second bolus of GHRH (1 micrograms/kg) administered two hours later. Pentagastrin infusion induced a rise in GH levels maximal at 60 min (9.1 + 0.6 ng/ml, mean + SE), but this rise was abolished by pretreatment with GHRH. Finally, we found that gastrin did not modify basal GH release or GH responses to GHRH by rat anterior pituitary cells in monolayer culture. Taken together, these data suggest that gastrin regulates GH secretion by acting at hypothalamic level.
Assuntos
Hormônio Liberador de Hormônio do Crescimento/fisiologia , Hormônio do Crescimento/metabolismo , Pentagastrina/farmacologia , Adulto , Animais , Células Cultivadas , Gastrinas/farmacologia , Hormônio Liberador de Hormônio do Crescimento/farmacologia , Humanos , Cinética , Fragmentos de Peptídeos/farmacologia , Adeno-Hipófise/efeitos dos fármacos , Adeno-Hipófise/metabolismo , RatosRESUMO
The alterations in serum concentration of thyroxine (T4), tri-iodine-thyronine (T3), reverse tri-iodinetiroinine (rT3), thyrotropine (TSH and free thyroxine index (IT4L), are studied in 37 patients diagnosed of sepsis who were divided into two groups according to their evolution: Group A: 22 patients who evolved favourably, and Group B: 15 patients who died, as well as in 14 healthy controls; this was carried out in order to establish, on one hand, its prognostic value, and, on the other, which of these parameters is most useful in the evaluation of thyroid function in these patients. A decrease in serum T3 levels was observed in patients from both groups (p less than 0.001) which was accompanied by an increase in rT3 levels (p less than 0.001) and a decrease in It4L (p less than 0.001); No significant modifications were observed in T4 and TSH. On follow up of 12 patients from group A and 14 from group B, an increase in mean T3 concentration was observed (p less than 0.02) only in the first patient from both groups. The greatest discriminative efficacy of thyroid hormones study with an unfavorable sepsis evolution corresponded to a T3 value below 35 ng/dl.