Effects of acute heat exposure on respiratory metabolism and blood glucose in freshwater fishes, Prochilodus scrofa (curimbatá) and Cyprinus carpio (carp) acclimatized to tropical winter

1. 1. Routine oxygen consumption and blood glucose were determined from freshwater fishes, Prochilodus scrofa and Cyprinus carpio, exposed at high temperatures for 1 hr. 2. 2. Prochilodus scrofa had a significantly higher rate of oxygen consumption at 30°C than at 25°C, and carp higher at 25°C than at 30°C. 3. 3. Blood glucose was significantly higher for Cyprinus carpio than for Prochilodus scrofa at 25 and 30°C; however, after exposure to these temperatures for 1 hr blood glucose did not change significantly for both species. 4. 4. The results suggest that these interspecific variations may be linked to the differences between native and foreign fishes and their way of life. © 1985.

The respiratory responses of an amphibious snail Pomacea lineata (spix, 1827), to temperature and oxygen tension variations

1. 1. The respiratory responses of Pomacea lineata to short-term (or acute) exposure to temperature and oxygen tension variations were investigated in animals acclimated to 25°C. 2. 2. The respiratory rates increased with rising temperatures; this increase was sharper between 15 and 25°C than at any other temperature interval; a tendency to a plateau in the RT curve was recorded between 25 and 35°C. 3. 3. All animals survived well to 1 hr exposure to the extreme temperatures used (5 and 40°C). 4. 4. In two different experimental approaches, the animals showed ability to regulate the respiratory rate in declining oxygen tensions, at least down to 10% (70.8 mmHg) oxygen. 5. 5. After 1 hr exposure to hypoxic conditions, P. lineata exhibited the pattern of underpayment of the oxygen debt acquired. 6. 6. Six out of ten animals survived after 40 days in anoxia (100% nitrogen). © 1987.

Thermoregulation and Respiratory Metabolism in two Brazilian Stingless Bee Subspecies of Different Climatic Distribution, Tetragonisca angustula fiebrigi and T a angustula (Hymenoptera: Apidae: Meliponinae)

The thermoregulatory capacity of colonies of the stingless bee subspecies Tetragonisca angustula fiebrigi Schwarz 1938, and Tetragonisca angustula angustula Latreille 1807, was investigated during winter and summer. The temperatures [T] inside and outside the nests were measured for 48 hh every 2 hh. In the brood area, the mean T observed for T a fiebrigi are 28.1° and 29.5° C, respectively, during winter and summer, whereas for T a angustula they are 28.6° and 31.6° C The ambient T in the same period range from 10.5° - 24.4° C (winter) and 20.1 - 36.3° C (summer). In workers, the respiratory rates [RR] increase with a rise in T, however, the differences between workers of the subspecies are not significant in contrast to the RR measured within subspecies in winter and summer. The Q10 values indicate an optimal T range from 15 - 25° C in winter, and from 20 - 30° C in summer for T a fiebrigi. For T a angustula the corresponding values were 25 - 35° C and 30 - 40° C, respectively.

Photosynthetic performance of freshwater Rhodophyta in response to temperature, irradiance, pH and diurnal rhythm

Responses of net photosynthetic rates to temperature, irradiance, pH/inorganic carbon and diurnal rhythm were analyzed in 15 populations of eight freshwater red algal species in culture and natural conditions. Photosynthetic rates were determined by oxygen concentration using the light and dark bottles technique. Parameters derived from the photosynthesis-irradiance curves indicated adaptation to low irradiance for all freshwater red algae tested, confirming that they tend to occur under low light regimes. Some degree of photoinhibition (β = -0.33-0.01 mg O2 g-1 DW h-1 (μmol photons m-2 s-1)-1) was found for all species/populations analyzed, whereas light compensation points (lc) were very low (≤ 2 μmol photons m- photons s-1) for most algae tested. Saturation points were low for all algae tested (lk = 6-54 μmol photons m-2 S-1; lS = 20-170 μmol photons m-2 s-1). Rates of net photosynthesis and dark respiration responded to the variation in temperature. Optimum temperature values for net photosynthesis were variable among species and populations so that best performances were observed under distinct temperature conditions (10, 15, 20 or 25°C). Rates of dark respiration exhibited an increasing trend with temperature, with highest values under 20-25°C. Results from pH experiments showed best photosynthetic performances under pH 8.5 or 6.5 for all but one species, indicating higher affinity for inorganic carbon as bicarbonate or indistinct use of bicarbonate and free carbon dioxide. Diurnal changes in photosynthetic rates revealed a general pattern for all algae tested, which was characterized by two relatively clear peaks, with some variations around it: a first (higher) during the morning (07.00-11.00 hours.) and a second (lower) in the afternoon (14.00-18.00 hours). Comparative data between the 'Chantransia' stage and the respective gametophyte for one Batrachospermum population revealed higher values (ca 2-times) in the latter, much lower than previously reported. The physiological role of the 'Chantransia' stage needs to be better analyzed.

Evaluation of cardiac rhythm in dogs treated with levamisole hydrochloride using 24-hour ambulatory electrocardiography

The objective of this study was to evaluate the electrocardiographic alterations in the cardiac rhythm in dogs treated with levamisole hydrochloride over a period of 24 hours. Thirty-six mixed-breed dogs, both male and female, all clinically healthy, were used in the experiment. The dogs were divided into 6 groups with 6 dogs in each group, according to dosage and route of administration. The Holter test was initiated immediately after the treatment, and was maintained for 24 hours. In the group treated with 10 mg/kg by way of subcutaneous injection, one of them showed ventricular premature complexes, sometimes isolated and other times in pairs, and ventricular tachycardia, concentrated mainly in the first hour after administration of the drug. In the group of 6 animals treated subcutaneously with 25mg/kg, four showed isolated ventricular premature complexes, ventricular bigeminy and trigeminy, mainly during the first 2 hours after administration of the drug. All the animals in the other groups showed sinus arrhythmia followed by sinus arrest. The disturbances in the cardiac rhythm observed in clinically healthy animals treated with levamisole hydrochloride, indicate that it is preferable to avoid subcutaneous administration of levamisole hydrochloride and that the oral administration of the drug should be done with caution. © 2003 Elsevier B.V. All rights reserved.

Acute and sustained effects of early administration of inhaled nitric oxide to children with acute respiratory distress syndrome

OBJECTIVE: To determine the acute and sustained effects of early inhaled nitric oxide on some oxygenation indexes and ventilator settings and to compare inhaled nitric oxide administration and conventional therapy on mortality rate, length of stay in intensive care, and duration of mechanical ventilation in children with acute respiratory distress syndrome. DESIGN: Observational study. SETTING: Pediatric intensive care unit at a university-affiliated hospital. PATIENTS: Children with acute respiratory distress syndrome, aged between 1 month and 12 yrs. INTERVENTIONS: Two groups were studied: an inhaled nitric oxide group (iNOG, n = 18) composed of patients prospectively enrolled from November 2000 to November 2002, and a conventional therapy group (CTG, n = 21) consisting of historical control patients admitted from August 1998 to August 2000. MEASUREMENTS AND MAIN RESULTS: Therapy with inhaled nitric oxide was introduced as early as 1.5 hrs after acute respiratory distress syndrome diagnosis with acute improvements in Pao(2)/Fio(2) ratio (83.7%) and oxygenation index (46.7%). Study groups were of similar ages, gender, primary diagnoses, pediatric risk of mortality score, and mean airway pressure. Pao(2)/Fio(2) ratio was lower (CTG, 116.9 +/- 34.5; iNOG, 62.5 +/- 12.8, p <.0001) and oxygenation index higher (CTG, 15.2 [range, 7.2-32.2]; iNOG, 24.3 [range, 16.3-70.4], p <.0001) in the iNOG. Prolonged treatment was associated with improved oxygenation, so that Fio(2) and peak inspiratory pressure could be quickly and significantly reduced. Mortality rate for inhaled nitric oxide-patients was lower (CTG, ten of 21, 47.6%; iNOG, three of 18, 16.6%, p <.001). There was no difference in intensive care stay (CTG, 10 days [range, 2-49]; iNOG, 12 [range, 6-26], p >.05) or duration of mechanical ventilation (TCG, 9 days [range, 2-47]; iNOG, 10 [range, 4-25], p >.05). CONCLUSIONS: Early treatment with inhaled nitric oxide causes acute and sustained improvement in oxygenation, with earlier reduction of ventilator settings, which might contribute to reduce the mortality rate in children with acute respiratory distress syndrome. Length of stay in intensive care and duration of mechanical ventilation are not changed. Prospective trials of inhaled nitric oxide early in the setting of acute lung injury in children are needed.

Effects of deltamethrin pyrethroid on the respiratory metabolism of the neotropical spirostreptid millipedes Gymnostreptus olivaceus and Plusioporus setiger

The effects of deltamethrin on the respiratory metabolism of Gymnostreptus olivaceus and Plusioporus setiger were investigated. Acetone solutions corresponding to half the LD50 values, i.e., 20 μg.g-1g for G. olivaceus and 4.40 μg.g-1 for P. setiger, were used. Metabolism was determined with a Warburg respirometer at 25°C. Respirometric measurements were performed 1, 3 and 6 hours after administration of the pyrethroid to the same groups of millipedes. After 24 hours, daily respirometric measurements lasting 1 hour each were made on different millipede groups for a period of 10 days. Significant differences were detected only between the groups treated with the pyrethroid and the two control groups. In G. olivaceus, respiratory rates increased by about 1.65-fold compared to normal immediately after administration of the pyrethroid, followed by a gradual decrease up to 72 hours and a return to normal levels thereafter. In P. setiger the increase was about 1.1-fold compared to normal, with a decrease up to 96 hours and a return to normal thereafter. Although increased oxygen consumption was observed, a detoxification process occurred in both species, so that the possible metabolism of the pyrethroid may justify the low toxicity of deltamethrin for G. olivaceus and P. setiger.

Respiratory and storage behavior of fresh cut 'Tommy Atkins' mango

The respiratory and storage behavior of fresh cut 'Tommy Atkins' mango, naturally ripened (NR) or with use of ethylene (RE), were studied. Fruits were selected, washed and disinfected (200 mgCl.L-1) and stored for 12 hours at 10°C. After this period, they were processed under hygienic conditions at 10°C, packaged in polyethylene terephthalate (PET) trays or in styrofoam trays wrapped with stretchable polyvinyl chloride (PVC) film and stored for up to 15 days at 3°C. The products were evaluated regarding the evolution of internal atmosphere in the packing (O2 and CO 2), development of weight, appearance, shelf life and consumer acceptability. The respiratory rate was measured before and after processing every two hours. The yield of 'Tommy Atkins' mango to produce fresh cut product was 48.09±0.95%. Increase of the respiration rate of both mango samples was verified one hour after the preparation (NR = 17.75 mL CO 2.kg-1.h-1; RE = 28.29 mL CO 2.kg-1.h-1), followed by stabilization at 3.76 and 8.07 mL CO2/kg.h, respectively. The percentage of O2 in packages was stable in all treatments, 15-20% in PVC trays, 18-20% in PET tray. The percentage of CO2 was steady around 1.5-2.5%. The products lost fresh mass during the storage, from 0.06% to 0.30% for PET trays and from 0.15% to 1.61% for trays covered with PVC. The appearance was considered appropriate for commercialization until the 13th day, whereas product from mangoes ripened with application of ethylene was for 11 days, presenting browning in the external surface. The naturally ripened mango presented the best flavor and consumer preference in relation to the mango ripened with application of ethylene for 11 days of storage. The control of hygienic conditions during the production and storage was good and with safety for until 10 days.

Respiratory chemoreceptor function in vertebrates - Comparative and evolutionary aspects

The sensing of blood gas tensions and/or pH is an evolutionarily conserved, homeostatic mechanism, observable in almost all species studied from invertebrates to man. In vertebrates, a shift from the peripheral O2-oriented sensing in fish, to the central CO2/pH sensing in most tetrapods reflects the specific behavioral requirements of these two groups whereby, in teleost fish, a highly O2-oriented control of breathing matches the ever-changing and low oxygen levels in water, whilst the transition to air-breathing increased the importance of acid-base regulation and O2-related drive, although retained, became relatively less important. The South American lungfish and tetrapods are probably sister groups, a conclusion backed up by many similar features of respiratory control. For example, the relative roles of peripheral and central chemoreceptors are present both in the lungfish and in land vertebrates. In both groups, the central CO2/pH receptors dominate the ventilatory response to hypercarbia (60-80), while the peripheral CO2/pH receptors account for 20-30. Some basic components of respiratory control have changed little during evolution. This review presents studies that reflect the current trends in the field of chemoreceptor function, and several laboratories are involved. An exhaustive review on the previous literature, however, is beyond the intended scope of the article. Rather, we present examples of current trends in respiratory function in vertebrates, ranging from fish to humans, and focus on both O2 sensing and CO2 sensing. As well, we consider the impact of chronic levels of hypoxia - a physiological condition in fish and in land vertebrates resident at high elevations or suffering from one of the many cardiorespiratory disease states that predispose an animal to impaired ventilation or cardiac output. This provides a basis for a comparative physiology that is informative about the evolution of respiratory functions in vertebrates and about human disease. Currently, most detail is known for mammals, for which molecular biology and respiratory physiology have combined in the discovery of the mechanisms underlying the responses of respiratory chemoreceptors. Our review includes new data on nonmammalian vertebrates, which stresses that some chemoreceptor sites are of ancient origin.

Positive selection results in frequent reversible amino acid replacements in the G protein gene of human respiratory syncytial virus

Human respiratory syncytial virus (HRSV) is the major cause of lower respiratory tract infections in children under 5 years of age and the elderly, causing annual disease outbreaks during the fall and winter. Multiple lineages of the HRSVA and HRSVB serotypes co-circulate within a single outbreak and display a strongly temporal pattern of genetic variation, with a replacement of dominant genotypes occurring during consecutive years. In the present study we utilized phylogenetic methods to detect and map sites subject to adaptive evolution in the G protein of HRSVA and HRSVB. A total of 29 and 23 amino acid sites were found to be putatively positively selected in HRSVA and HRSVB, respectively. Several of these sites defined genotypes and lineages within genotypes in both groups, and correlated well with epitopes previously described in group A. Remarkably, 18 of these positively selected tended to revert in time to a previous codon state, producing a flipflop phylogenetic pattern. Such frequent evolutionary reversals in HRSV are indicative of a combination of frequent positive selection, reflecting the changing immune status of the human population, and a limited repertoire of functionally viable amino acids at specific amino acid sites.

Nucleotide and phylogenetic analysis of human papillomavirus types 6 and 11 isolated from recurrent respiratory papillomatosis in Brazil

There are few studies about the distribution of natural molecular variants of low-risk HPVs. Our aim was to evaluate the E6 early gene variability among HPV-6 and HPV-11 isolates detected in recurrent respiratory papillomatosis (RRP) samples obtained in a cohort of Brazilian patients. We also performed a phylogenetic analysis in order to compare nucleotide sequences identified in our study with previously reported isolates from different anatomic sites (laryngeal papillomas, genital warts, cervical cancer and anal swabs) obtained from other parts of the world to determine the phylogenetic relationships of variants detected in Brazil. The complete coding region of the E6 gene of 25 samples was cloned and sequenced: 18 isolates of HPV-6 (72%) and 7 isolates of HPV-11 (28%). A total of four different HPV-6 genomic variants and two HPV-11 genomic variants was identified. It was not possible to correlate specific variants with disease severity. Phylogenetic trees for both HPV types were constructed enclosing both E6 sequences detected in our study and formerly published sequences. In both phylogenetic trees, the sequences from Brazil did not group together. We could not establish a geographical association between HPV-6 or HPV-11 variants, unlike HPV-16 and HPV-18. © 2013 Elsevier B.V.

Versão brasileira do Chronic Respiratory Questionnaire: estudo da validade de constructo e reprodutibilidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliações cardiovasculares e comportamentais em gatos após a injeção intravenosa de amitraz ou xilazina

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Avaliação da anestesia por isofluorano em eqüinos submetidos à infusão contínua de medetomidina ou xilazina

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

Avaliação clínica da cardiomiopatia chagásica crônica em cães

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)