242 resultados para CIRCULATORY AND RESPIRATORY PHYSIOLOGY


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Larvae of an estuarine grapsid crab Chasmagnathus granulata Dana 1851, from temperate and subtropical regions of South America, were reared in seawater (32 ‰) at five different constant temperatures (12, 15, 18, 21, 24 °C). Complete larval development from hatching (Zoea I) to metamorphosis (Crab I) occurred in a range from 15 to 24 °C. Highest survival (60% to the first juvenile stage) was observed at 18°C, while all larvae reared at 12°C died before metamorphosis. The duration of development (D) decreased with increasing temperature (T). This relationship is described for all larval stages as a power function (linear regressions after logarithmic transformation of both D and T). The temperature-dependence of the instantaneous developmental rate (D-1) is compared among larval stages and temperatures using the Q10 coefficient (van't Hoff's equation). Through all four zoeal stages, this index tends to increase during development and to decrease with increasing T (comparing ranges 12-18, 15-21, 18-24 °C). In the Megalopa, low Q10 values were found in the range from 15 to 24 °C. In another series of experiments, larvae were reared at constant 18°C and their dry weight (W) and respiratory response to changes in T were measured in all successive stages during the intermoult period (stage C) of the moulting cycle. Both individual and weight-specific respiration (R, QO2) increased exponentially with increasing T. At each temperature, R increased significantly during growth and development through successive larval stages. No significantly different QO2 values were found in the first three zoeal stages, while a significant decrease with increasing W occurred in the Zoea IV and Megalopa. As in the temperature-dependence of D, the respiratory response to changes in temperature (Q10) depends on both the temperature range and the developmental stage, however, with different patterns. In the zoeal stages, the respiratory Q10 was minimum (1.7-2.2) at low temperatures (12-18 °C), but maximum (2.2-3.0) at 18-24 °C. The Megalopa, in contrast, showed a stronger metabolic response in the lower than in the upper temperature range (Q10 = 2.8 and 1.7, respectively). We interpret this pattern as an adaptation to a sequence of temperature conditions that should typically be encountered by C. granulata larvae during their ontogenetic migrations: hatching in and subsequent export from shallow estuarine lagoons, zoeal development in coastal marine waters, which are on average cooler, return in the Megalopa stage to warm lagoons. We thus propose that high metabolic sensitivity to changes in temperature may serve as a signal stimulating larval migration, so that the zoeae should tend to leave warm estuaries and lagoons, whereas the Megalopa should avoid remaining in the cooler marine waters and initiate its migration towards shallow coastal lagoons.

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Incubating eggs (1,800 total) produced by a commercial flock of Cobb broiler breeders were used to determine the effects of storage duration (3 and 18 d) on gas partial pressure, thyroid hormones, and hatching parameters. Partial pressure of oxygen (pO2) and carbon dioxide (pCO2) were measured on d 18 and at internal pipping (IP) during incubation. Blood samples were collected for determination of triiodothyronine (T3), thyroxine (T4), and corticosterone concentrations in the embryos at IP and in newly hatched chicks. From 464 to 510 h of incubation, eggs were checked individually every 2 h to determine the timing and duration of IP, external pipping (EP), and total hatching time. At 18 d of incubation and at IP, pCO2 was greater in air cell of eggs stored for 3 d compared to those stored for 18 d (P < 0.05), but pO2 was greater in eggs stored for 18 d. At IP, T3 and corticosterone levels were higher in plasma of the embryos of eggs stored for 3 d compared to those stored for 18 d, but it was the reverse in newly hatched chicks (P < 0.05). Embryos from eggs stored for 18 d required more time to complete IP compared to embryos of eggs stored for only 3 d (P < 0.05), whereas the duration of EP was not affected by storage. The overall longer incubation was, however, not only due to prolonged IP but also to later occurrence of IP. It was concluded that prolonged IP as a result of long storage may be related to the late increase in corticosterone level, which may be a necessary stimulus for higher T 3/T4 ratio, late increase in pCO2 level, and decrease in pO2. The effect of long storage was a delay in hatching and a continuous increase in T3 due to higher corticosterone levels between IP and hatching, which may be an indication of the more stressful event of hatching of embryos from eggs stored longer. Differences in pCO2, pO2, T3, T4, and corticosterone levels in the incubating eggs may be manifestations of these changes culminating in altered hatching parameters and consequently differences in chick quality and growth potentials.

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Objective: The present study aimed at evaluating the occurrence and recurrence of middle ear effusion and possible associated factors in the first two years of life of 190 newborns and infants, participants in the interdisciplinary prevention, detection, and intervention program at the Clínica de Educação para Saúde of Universidade do Sagrado Coração, Methods: Newborns and infants were monthly submitted to anamneses, otoscopy, behavioral hearing assessment using sound instruments and pure tones (pediatric audiometry) and tympanometry. Results: The results revealed that 68.4% of infants presented one or more episodes of middle ear effusion during their two first years, with more recurrence among males. Peak occurrence was between four and 12 months of age and, the earlier the first episode, the higher the probability of recurrence. Greatest incidence was during May and August. It was found that, of the variables investigated, the period of exclusive breastfeeding actuated as a protector factor. With respect of risk factors, it was observed that passive smoking, gastro-esophageal reflux and respiratory allergy were related with the recurrences of effusion. Conclusion: Findings revealed the importance of periodic auditory follow-up for infants during their first two years of life, considered to be the critical period of auditory system maturation, during which sensory deprivation can be responsible for damage to the development of speech, language and other auditory abilities. Copyright © 2005 by Sociedade Brasileira de Pediatria.

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The regeneration of plant communities from seed depends, to a large extent, on the capacity of the seed remaining viable in the soil. The viability and germination of artificially buried Psychotria vellosiana seeds in cerrado soil were studied, with the purpose of discovering some physio-ecological aspects of dispersed seeds and evaluating their potential to constitute a soil seed bank. Seed samples were placed in nylon envelopes and buried in the soil of a Cerrado reserve at two different depths and sites. Buried seeds were retrieved periodically and tested for germination along with dry-stored seeds. In general, there was a reduction in seed germination with storage time, both in soil and dry stored conditions, and in some assays exhumed seeds germinated faster than dry stored ones. In general the soil storage favoured seed viability of ungerminated seeds as compared to dry stored ones, with the seeds remaining partially viable after 10 months of storage. The lack of germination of viable seeds suggests that seeds showed true dormancy and/or required an extended time to germinate. It was observed that some seeds had germinated while buried and such in situ germination tended to increase with rainfall. The water availability in the soil might be a limiting factor for successful germination of P. vellosiana in the field, and the seeds may constitute a persistent soil seed bank in the cerrado as dispersed seeds remain viable in the soil until the following period of seed dispersal.

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This study evaluated the efficacy of dietary vitamin C (ascorbic acid or AA), vitamin E (α-tocopherol or α-T), and C + E supplementation on the blood parameters of Arapaima gigas grown in net cages for 45 days. Four treatments were tested: control (commercial feed); C800; E500 and C + E (800 + 500) with supplementation of 800 mg AA kg- 1, 500 mg α-T kg- 1 and 800 + 500 mg AA + α-T kg- 1, respectively. Hematocrit (Ht), red blood cells (RBC), and hemoglobin concentration (Hb) (oxidative status indicators), thrombocytes and leukocytes (immunological indicators), plasma protein and glucose were evaluated. Fish fed vitamin C and C + E supplemented diets showed greater weight gain and survival. Dietary vitamin C and C + E diet supplementation resulted in increased Ht, Hb, RBC, MCHC, total leukocytes, total proteins, thrombocytes and eosinophils compared to the control and α-T. The α-tocopherol-supplemented diet reduced the number of total thrombocytes, lymphocytes and neutrophils and increased glucose and eosinophils relatively to the control. In general, leukocytes and thrombocytes were good indicators of the efficiency of vitamin on the defense mechanism of the A. gigas reared in cages. Results indicate that high α-T diet supplementation provides no benefit for the maintenance of the oxidative or the immunological status of A. gigas. However, it was demonstrated that high dietary AA improves A. gigas immunological status. Red blood cell indices and immune system indicators showed no synergistic effect between the vitamins after supplementing the A. gigas diet with α-T + AA. © 2006 Elsevier Inc. All rights reserved.

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The aim of this work was to evaluate the effect of physical preconditioning in the responsiveness of rat pulmonary rings submitted to lung ischemia/reperfusion (IR). Wistar rats were divided into three groups: Sedentary sham-operated (SD/SHAM); sedentary submitted to ischemia/reperfusion (SD/IR) and trained submitted to ischemia/reperfusion (TR/IR) animals. Exercise training consisted in sessions of 60 min/day running sessions, 5 days/week for 8 weeks. Left pulmonary IR was performed by occluding for 90 min and reperfusing for 120 min. After that, pulmonary arteries were isolated and concentration-response curves to acetylcholine (ACh), histamine (HIST), sodium nitroprusside (SNP), phenylephrine and U46619 were obtained. Neither potency (- log EC50) nor maximal responses (Emax) were modified for ACh and HIST in all groups. On the other hand, the potency for SNP was significantly increased in TR/IR group (8.23 ± 0.06) compared to SD/IR group (7.85 ± 0.04). Contractile responses mediated by a-adrenergic receptor were markedly decreased in IR groups (SD/IR: 6.75 ± 0.06 and TR/IR: 6.62 ± 0.04) compared to SD/SHAM (7.33 ± 0.05). No changes were seen for the U46619 in all groups. In conclusion, the present study shows that exercise training has no protective actions in the local blood vessel where the IR process takes place. © 2006 Elsevier Inc. All rights reserved.

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The objective of this study was to estimate the prevalence of adverse drug reactions (ADR) related to hospital admission of elderly people, identifying the use of potentially inappropriate medication (PIM), the ADR and the risk factors associated with the hospitalization. A cross-sectional study was conducted in a private hospital of São Paulo State, Brazil. All patients aged ≥ 60 years, admitted in the general practice ward in May 2006 were interviewed about the drugs used and the symptoms/complaints that resulted in hospitalization. More than a half (54.5 %) of elderly hospitalizations were related with ADR. The therapeutic classes involved with ADR were: cardiovascular (37.7 %), central nervous (34.6 %) and respiratory (5.7 %). The ADR observed were disorders in circulatory (28.4 %), digestive (20.0 %) and respiratory (18.9 %) tracts. 27 elderly had made PIM and in 20 of them this was the cause of hospitalization. Polypharmacy was an ADR risk factor (p = 0.021).These data allows the healthcare professionals upgrade, qualifying them in pharmcovigilance.

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Objective. Collate and update knowledge in relation to physical therapy in spinal cord injury (SCI) in the intensive care unit (ICU). Method. We performed a literature update in the databases Lilacs, PubMed and Scielo, crossing the descriptors spinal cord injury, cinesiotherapy, physiotherapy, mobilization, rehabilitation, intensive care unit, respiratory therapy and electrotherapy in the period of 2005 to 2010. Results. We found 21 studies, however, only five articles met the inclusion criteria. Kinesiotherapy is essential since the phase of spinal shock, since it favors the maintenance of joint range of motion and flexibility, and to prevent circulatory complications caused/ resulted from prolonged immobilization in bed. Respiratory therapy promotes bronchial hygiene, correction of abnormal respiratory patterns and respiratory diseases. The electrotherapy is a feature still little used by physiotherapists in the intensive care units. Conclusions. The physical therapy in SCI in ICU is focused on motor rehabilitation through kinesiotherapy and intervention through the respiratory bronchial hygiene and training of respiratory muscles. New treatment modalities such as electrotherapy, there have been in intensive environment, there is a need for more studies to confirm benefits and risks of this feature in the spinal cord.

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Orbifloxacin is a third generation of fluoroquinolone that exhibits increased antibacterial activity against the Enterobacteriaceae, gram-negative and gram-positive bacteria, anaerobes, and mycobacteria. This drug was synthesized in 1987 and developed as a veterinary chemotherapeutic to use for livestock and domestic pets. Orbifloxacin is labeled for the treatment of skin, soft tissue, and urinary tract infections in dogs, and skin and soft tissue infections in cats, but in some countries, orbifloxacin has been given for the treatment of gastrointestinal and respiratory infections in cattle and swine and other animals. The in vitro activity and clinical efficacy of orbifloxacin against naturally occurring bacterial infections of the skin, ear, soft tissue, udder, and gastrointestinal and respiratory systems in different animals have been evaluated and good responses have been found. The minimum inhibitory concentration of orbifloxacin has been determined in various different pathogens and the results found in the literature are shown in this work. The pharmacokinetics of orbifloxacin has been evaluated by different routes of administration in goats, horses, pigs, rabbits, dogs, cats, camels, cattle, sheep, and fish. Orbifloxacin exhibits excellent pharmacokinetic parameters that suggest that this drug may have good clinical effects on various bacterial infections in these species. All methods described in the scientific literature for determination of orbifloxacin in different matrices were collected and discussed. © 2013 Copyright Taylor and Francis Group, LLC.

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The effects of shading and water sprinkling on physiological responses and milk production were studied in Holstein cows managed in an equatorial semi-arid region. Five cows were observed for 36 days during May and June 2009. We studied the effects of sun, shade, shade plus single sprinkling, shade plus sprinkling every 2. h and shade plus sprinkling every hour on physiological responses, i.e., rectal temperature, coat surface temperature and respiratory rate, and on milk production. Environmental variables, i.e., air temperature, black globe temperature, mean radiant temperature, relative humidity and wind speed, were recorded every 30. min throughout the observation period. The statistical analysis utilized a 5×5 replicated latin square, and the results showed reduced values in physiological variables in cows that were protected from short wave radiation and that received water sprinkling; milk yield increased by approximately 3.5. kg in such animals relative to those not receiving such treatment. However, the milk yield for the morning milking presented similar mean values regardless of whether the animals received shading and sprinkling benefits, which indicates that frequency of sprinkling and amount of time (permanence) in the shade were critical for the effect on milk yield. © 2013 Elsevier B.V.

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The nucleus of the solitary tract (NTS) is the primary site of visceral afferents to the central nervous system. In the present study, we investigated the effects of lesions in the commissural portion of the NTS (commNTS) on the activity of vasopressinergic neurons in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei, plasma vasopressin, arterial pressure, water intake, and sodium excretion in rats with plasma hyperosmolality produced by intragastric 2 M NaCl (2 ml/rat). Male Holtzman rats with 15-20 days of sham or electrolytic lesion (1 mA; 10 s) of the commNTS were used. CommNTS lesions enhanced a 2 M NaCl intragastrically induced increase in the number of vasopressinergic neurons expressing c-Fos in the PVN (28 ± 1, vs. sham: 22 ± 2 c-Fos/AVP cells) and SON (26 ± 4, vs. sham: 11 ± 1 c-Fos/AVP cells), plasma vasopressin levels (21 ± 8, vs. sham: 6.6 ± 1.3 pg/ml), pressor responses (25 ± 7 mmHg, vs. sham: 7 ± 2 mmHg), water intake (17.5 ± 0.8, vs. sham: 11.2 ± 1.8 ml/2 h), and natriuresis (4.9 ± 0.8, vs. sham: 1.4 ± 0.3 meq/1 h). The pretreatment with vasopressin antagonist abolished the pressor response to intragastric 2 M NaCl in commNTS-lesioned rats (8 ± 2.4 mmHg at 10 min), suggesting that this response is dependent on vasopressin secretion. The results suggest that inhibitory mechanisms dependent on commNTS act to limit or counterbalance behavioral, hormonal, cardiovascular, and renal responses to an acute increase in plasma osmolality. © 2013 the American Physiological Society.

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Even though community-acquired methicillin resistant Staphylococcus aureus (CA-MRSA) was described a decade ago, reports from Brazil are scarce and cases occurred in large urban centers. We report MRSA sepsis in a 16-year-old male from a small town and who had no history of exposure to healthcare or recent travel. After trauma during a soccer match, he presented swelling in the right thigh, which evolved in a month to cellulitis complicated by local abscess, orchitis and pneumonia. The patient presented severe sepsis, with fever and respiratory failure. Laboratory findings included blood leukocyte counts above 40,000/mm3 and thrombocytopenia. He was submitted to mechanical ventilation and therapy with vancomycin and imipenem. He had a slow but favorable response to therapy and was discharged after six weeks of hospitalization. MRSA grew from blood cultures and respiratory aspirates obtained before antimicrobial therapy. The isolate belonged to sequence type 5, spa type t311, harbored SCCmec type IV and genes for Panton-Valentine leukocidin and Enterotoxin A. The pulsed-field gel electrophoresis pattern was distinct from North American classic CA-MRSA clones. However, the sequence type and the spa type revealed that the clone belong to the same clonal complex isolated in Argentina. This is the first CA-MRSA infection reported in that region, with significant epidemiologic and clinical implications. © 2013 Elsevier Inc.

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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

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Buffaloes and bovines are polyestrous and seasonal or annual livestock, respectively, that show reduced fertility during heat stress. To investigate whether reduced fertility is related to oocyte competence in both species, immature oocytes from buffalo and bovine heifers were collected during winter and summer and subjected to molecular analyses. In each season, heifers of both species had their follicular wave emergence synchronized with a standard protocol (Ferreira et al., 2011). Before being subjected to ovum pick up (OPU), cutaneous (CT; degrees C) and rectal (RT; degrees C) temperatures and respiratory rate (RR; breaths/min) were measured. Oocytes' RNA was extracted to evaluate the expression of target genes related to mtDNA replication/transcription (PPARGC1A, TFAM and MT-CO1), apoptosis (BAX and BCL2) and HS (HSP90AA1 and HSPA1AB). ACTB, HIST1H2AG and GAPDH were initially chosen as housekeeping genes. In buffaloes, CT (35.0 +/- 0.4 vs 23.8 +/- 0.5), RT (38.7 +/- 0.1 vs 38.0 +/- 0) and RR (21.3 +/- 1.2 vs 15.4 +/- 1.1) were higher during summer than winter. However, in bovine heifers, RT (38.7 +/- 0.1 vs 38.6 +/- 0.1) and RR (44.8 +/- 1.5 vs 40.6 +/- 1.5) were similar in both seasons, while CT (31.6 +/- 0.3 vs 30.2 +/- 0.3) was increased during summer. Reduced expression of ACTB, HIST1H2AG and GAPDH was evidenced during summer, disqualifying them as housekeeping genes. Similarly, the expression of all target genes was reduced during summer in oocytes of both species. In summary, physiological responses to heat stress seem to be more intense in buffalo than bovine heifers. However, in both species, negative effects of heat stress upon oocyte quality occur at the molecular level and affects genes related to several biological functions.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)