Torpor in three species of Brazilian hummingbirds under semi-natural conditions

We measured body temperatures in three species of Brazilian hummingbirds, the Versicolored Emerald (Amazilia versicolor; body mass 4.1 g), the Black Jacobin (Me lantrochilus fuscus; body mass 7.7 g) and the Swallow-tailed Hummingbird (Eupetomena macroura; body mass 8.6 g), during overnight exposure to natural conditions of photoperiod and ambient temperatures. All three species entered torpor. In both A. versicolor and E. macroura, individuals entered torpor even if they had access to feeders up to the time of sunset. In contrast, M. fuscus was less prone to enter torpor and did so mainly if it had been fasting for more than two hours before sunset. Furthermore, M. fuscus often spent the whole night in torpor, whereas the two other species entered torpor for a variable, often short, period of the night. We observed more than one torpor bout during a single night in all three species. We suggest that multiple nocturnal torpors result from interruption of the normal torpor pattern by some (unknown) external stimuli. Any interrupted torpor was always followed by a new entry into torpor, supporting the view that there is a body mass threshold below which the hummingbirds must enter torpor Our data also indicate that these hummingbird species might use torpor even if they are not energetically stressed.

Injeção inadvertida de metoclopramida no espaço subaracnóideo: relato de caso

JUSTIFICATIVA E OBJETIVOS: Injeção inadvertida de medicamentos de uso não espinhal nos espaços peridural e subaracnóideo é uma complicação anestésica passível de ocorrer. Este relato apresenta um caso de injeção inadvertida de metoclopramida no espaço subaracnóideo. RELATO do CASO: Paciente do sexo feminino, 17 anos, 69 kg, IMC de 26.2, estado físico ASA I, 36 semanas e 4 dias de gestação, com diagnóstico de sofrimento fetal agudo, e indicação de cesariana. Apresentava freqüência cardíaca de 82 bpm, pressão arterial de 130 x 70 mmHg, SpO2 de 97%, ritmo cardíaco sinusal regular. A anestesia foi por via subaracnóidea com a associação de anestésico local e opióide, 15 mg de bupivacaína hiperbárica a 0,5% e 25 µg de fentanil. Após 5 minutos da instalação do bloqueio, a paciente referiu mal estar inespecífico. Aferidas pressão arterial, 190 x 120 mmHg, freqüência cardíaca, 145 bpm, e SpO2, 95%. Verificando-se as ampolas cujos conteúdos foram administrados encontrou-se uma de bupivacaína e uma de metoclopramida. O quadro se apresentou com cefaléia frontal intensa, visão turva, náuseas, vômitos e agitação inicial, que evoluiu para sonolência e torpor, além de hipertensão arterial e taquicardia. Foram administrados tramadol, dipirona, ondansetron e medidas de suporte. Após 30 minutos, a paciente apresentava-se assintomática, com PA de 150 x 100 mmHg e FC de 120 bpm. Recebeu alta para a enfermaria 140 minutos após permanência na SRPA, com total reversão dos bloqueios motor, sensitivo e autonômico, e normalização dos parâmetros hemodinâmicos. Recebeu alta hospitalar 48 horas após, sem apresentar seqüelas neurológicas, juntamente com o recém-nascido. CONCLUSÕES: Máxima atenção deve ser dada a qualquer medicamento administrado, seja qual for à via utilizada. Padronização de cores de ampolas, e dos locais de depósito, com o intuito de diminuir este tipo de acidente é recomendável.

Thermogenic capacity of three species of fruit-eating phyllostomid bats

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

Thermoregulation by an Australian murine rodent, the ash-grey mouse (Pseudomys albocinereus)

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

The relationship between diet quality and basal metabolic rate in endotherms: Insights from intraspecific analysis

In this article, we review intraspecific studies of basal metabolic rate (BMR) that address the correlation between diet quality and BMR. The food-habit hypothesis stands as one of the most striking and often-mentioned interspecific patterns to emerge from studies of endothermic energetics. Our main emphasis is the explicit empirical comparison of predictions derived from interspecific studies with data gathered from within-species studies in order to explore the mechanisms and functional significance of the putative adaptive responses encapsulated by the food-habit hypothesis. We suggest that, in addition to concentrating on the relationship among diet quality, internal morphology, and BMR, new studies should also attempt to unravel alternative mechanisms that shape the interaction between diet and BMR, such as enzymatic plasticity, and the use of energy-saving mechanisms, such as torpor. Another avenue for future study is the measurement of the effects of diet quality on other components of the energy budget, such as maximum thermogenic and sustainable metabolic rates. It is possible that the effects of diet quality operate on such components rather than directly on BMR, which might then push or pull along changes in these traits. Results from intraspecific studies suggest that the factors responsible for the association between diet and BMR at an ecological timescale might not be the same as those that promoted the evolution of this correlation. Further analyses should consider how much of a role the proximate and ultimate processes have played in the evolution of BMR.

Selection of environmental temperature by the yellow scorpion Tityus serrulatus Lutz & Mello, 1922 (Scorpiones, Buthidae)

The preferred temperature of the yellow scorpion Tityus serrulatus was investigated since its dispersion is a matter of concern. Adult T. serrulatus, weighing 1.24 ± 0.20 g (mean + sd) and with a standard length of 59.3 ± 2.5 mm, were used. A metallic corridor (120 cm long, 5 cm large and 10 cm high) with thermal gradient ranging from 0°C to 40°C was used. Tityus serrulatus chose and stayed in temperatures ranging from 14° C to 38°C when safe conditions were offered (dark and thigmotactic stimuli). The number of animals that remained in the 11°C-20°C, 21°C-30°C, and 31°C-40°C temperature zones were 8, 8, and 9, respectively. The chi-square test (degree of freedom = 2) showed that differences were not significant (p>0.05). Some animals moved to lower temperature areas (less than 8°C) when the corridor was completely illuminated and thigmotactic stimuli were absent, which led the animals to present a torpor state. It is concluded that T. serrulatus does not select a specific environmental temperature. Associated with the capacity of temporally surviving at low temperatures, this species seems to be highly adaptable to different thermal zones.

Metabolic, ventilatory, and hygric physiology of the gracile mouse opossum (Gracilinanus agilis)

We present the first complete study of basic laboratory-measured physiological variables (metabolism, thermoregulation, evaporative water loss, and ventilation) for a South American marsupial, the gracile mouse opossum (Gracilinanus agilis). Body temperature (Tb) was thermolabile below thermoneutrality (Tb = 33.5°C), but a substantial gradient between Tb and ambient temperature (Ta) was sustained even at Ta = 12°C (Tb = 30.6°C). Basal metabolic rate of 1.00 mL O2 g-1 h-1 at Ta = 30°C conformed to the general allometric relationship for marsupials, as did wet thermal conductance (5.7 mL O2 g-1 h-1 °C-1). Respiratory rate, tidal volume, and minute volume at thermoneutrality matched metabolic demand such that O2 extraction was 12.4%, and ventilation increased in proportion to metabolic rate at low T a. Ventilatory accommodation of increased metabolic rate at low Ta was by an increase in respiratory rate rather than by tidal volume or O2 extraction. Evaporative water loss at the lower limit of thermoneutrality conformed to that of other marsupials. Relative water economy was negative at thermoneutrality but positive below Ta = 12°C. Interestingly, the Neotropical gracile mouse opossums have a more positive water economy at low Ta than an Australian arid-zone marsupial, perhaps reflecting seasonal variation in water availability for the mouse opossum. Torpor occurred at low Ta, with spontaneous arousal when . T b > 20°C. Torpor resulted in absolute energy and water savings but lower relative water economy. We found no evidence that gracile mouse opossums differ physiologically from other marsupials, despite their Neotropical distribution, sympatry with placental mammals, and long period of separation from Australian marsupials. © 2009 by The University of Chicago. All rights reserved.

Morphological Variation of Primary Reproductive Structures in Males of Five Families of Neotropical Bats

Bats present unique features among mammals with respect to reproduction, and although neotropical bats do not have a hibernation period, many of their reproductive characteristics vary seasonally and interspecifically. Thus, this work aimed to examine the reproductive structures of 18 species belonging to five families of Brazilian bats. The gross anatomy of the testes varied little; however, the epididymis of Emballonuridae and Vespertilionidae showed exceptional structures with a large elongation of the caudal region. We observed a wide variation in the positioning of the testes: Phyllostomidae and Noctilionidae presented external testes; Emballonuridae and Molossidae presented migratory testes that may be in intra-abdominal or external positions; and Vespertilionidae displayed scrotal testes. In the histological evaluation, we observed a different pattern in vespertilionid species, with testicular regression and sperm retention/storage in the cauda epididymis in the five species analyzed. Similar testicular regression was observed in Molossops temminckii; however, sperm retention/storage was not observed in this species. These data suggest that although the species analyzed are tropical species that do not present a prolonged period of torpor (hibernation), they still maintain a period of seminiferous tubule regression and sperm storage very similar to that observed in hibernating bats. © 2012 Wiley Periodicals, Inc.

Uso de rastreadores de eventos adversos a medicamentos para farmacovigilância no âmbito hospitalar

Eventos adversos a medicamentos (EAM) ainda são uma das principais limitações nos serviços de cuidados com a saúde, causando risco aos pacientes, além de grande impacto econômico. Assim, fazem-se necessários métodos de identificação de eventos adversos mais eficazes que a tradicional notificação espontânea, a qual revela apenas 5% do total de eventos. A utilização de critérios rastreadores (ou trigger tools), elaborados pelo Institute for Healthcare Improvement, tem se mostrado como a alternativa mais válida e eficiente para a triagem dos EAM. Com o objetivo principal de identificar os principais eventos adversos e medicamentos envolvidos, uma seleção de três critérios rastreadores foi utilizada, a saber: INR (razão normalizada internacional) > 6, WBC (contagem de leucócitos) < 3000/mm³ ou registros de episódios de sedação excessiva, letargia ou queda. Informações sobre os rastreadores foram coletadas e analisadas a partir dos prontuários de pacientes internados no Hospital Estadual Américo Brasiliense internados, de novembro de 2011 a janeiro de 2012 e maio a julho de 2012, a fim de se confirmar a ocorrência de evento adverso. Foram analisados prontuários referentes a 3318 hospitalizações, nas quais foram detectados 69 eventos adversos, 49 dos quais foram causados por apenas quatro das 12 classes de medicamentos envolvidos em algum EAM: anticoagulantes orais, relacionados ao rastreador INR>6 (eficácia = 0,75), sedativos e antipsicóticos, relacionados ao rastreador de sedação excessiva, letargia ou queda (eficácia = 0,52), e antivirais, relacionados ao rastreador WBC<3000 (eficácia = 0,48). Quando os rastreadores eram acionados e não estavam relacionados a EAM, os fatores de confusão mais recorrentes foram: torpor secundário ao quadro clínico, acidentes não relacionados ao medicamento e pacientes propositalmente em regime de sedação. Apesar de valores-limite menos radicais poderem aumentar a ...

Moulting behavior in leaf-frogs of the genus phyllomedusa (Anura : hylidae)

The species belonging to the subfamily Phyllomedusinae presents physiological and behavioral adaptations to economise water such as secretion of lipids coupled with its spreading onto the skin surface through a complex behavior, adoption of diurnal torpor and secretion of uric acid. Here we describe other adaptation probably involved with water economy, registered in Phyllomedusa distincta, P. tarsius, P. tetraploidea and natural hybrids of P. distincta and P. tetraploidea - at dusk, these amphibians perform an elaborate moulting behavior that encompasses the cleaning of the body with the limbs plus gaping and body contractions. Our data show the daily moulting in P. distincta and suggest that the same mechanism occurs for the other species studied. We suppose that daily moulting improves the skin permeability to water being a characteristic of the phyllomedusines which spread lipids onto the skin surface.