Heterogeneity in the preferential diet of neotropical bats impacts the pancreatic islet mass and α and ß cell distribution.

Whether there is a relationship between bats' dietary patterns and evolutionary endocrine pancreas adaptation is not clearly understood. Aiming to contribute to this topic, we evaluated some metabolic and structural parameters in the following adult bats: the frugivorous Artibeus lituratus, the nectarivorous Anoura caudifer, the hematophagous Desmodus rotundus, and the insectivorous Molossus molossus. A. lituratus and A. caudifer diets consist of high amounts of simple carbohydrates, while D. rotundus and M. molossus diets consist of high amounts of proteins or protein and fat, respectively. In our results, A. lituratus and A. caudifer bats exhibited the highest values of relative islet mass (%), islet density (number of islets per pancreas area), and the lowest values of intestinal length among the four species. When adjusted by the body mass (mg/g of body mass), both D. rotundus and A. caudifer bats exhibited the highest islet mass values among the groups. Blood glucose was similar between A. lituratus, D. rotundus, and M. molossus, with the lowest values for the A. caudifer bats. M. molossus bats had the highest plasma cholesterol values among the studied species but exhibited similar plasma triacylglycerol with D. rotundus and A. caudifer bats. ß- and α-cell distribution within A. lituratus, A. caudifer, and M. molossus islets achieved an approximate average value of âˆ¼ 66% and âˆ¼ 28%, respectively, a pattern inverted in D. rotundus islets (53% of α cells and 40% of ß cells). A. caudifer and D. rotundus exhibited the highest and the lowest ß/α-cells ratio per islet, respectively. We conclude that the macronutrient predominance in each bat-eating niche correlates with the morphophysiological pancreas features being the nectarivorous A. caudifer the species with the highest islet mass per body mass and ß/α-cells ratio, while the hematophagous D. rotundus showed the highest α-cells apparatus.

How do pesticides affect bats? - A brief review of recent publications.

Increased agricultural production has been increased use of pesticides worldwide, which poses a threat to both human and environmental health. Recent studies suggest that several non-target organisms, from bees to mammals, show a wide variety of toxic effects of pesticides exposure, including impaired behavior, development and reproduction. Among mammals, bats are usually a neglected taxon among ecotoxicological studies, although they play important ecological and economical roles in forest ecosystems and agriculture through to seed dispersal and insect population control. Considering their wide variety of food habits, bats are exposed to environmental pollutants through food or water contamination, or through direct skin contact in their roosting areas. In order to better understand the risk posed by pesticides to bats populations, we compiled studies that investigated the main toxicological effects of pesticides in bats, aiming at contributing to discussion about the environmental risks associated with the use of pesticides.

How do pesticides affect bats? - A brief review of recent publications / Como os pesticidas afetam os morcegos? - Uma breve revisão de publicações recentes

Increased agricultural production has been increased use of pesticides worldwide, which poses a threat to both human and environmental health. Recent studies suggest that several non-target organisms, from bees to mammals, show a wide variety of toxic effects of pesticides exposure, including impaired behavior, development and reproduction. Among mammals, bats are usually a neglected taxon among ecotoxicological studies, although they play important ecological and economical roles in forest ecosystems and agriculture through to seed dispersal and insect population control. Considering their wide variety of food habits, bats are exposed to environmental pollutants through food or water contamination, or through direct skin contact in their roosting areas. In order to better understand the risk posed by pesticides to bats populations, we compiled studies that investigated the main toxicological effects of pesticides in bats, aiming at contributing to discussion about the environmental risks associated with the use of pesticides.

O aumento da produção agrícola tem levado ao aumento do uso de pesticidas em todo o mundo, o que representa uma ameaça para a saúde humana e ambiental. Estudos recentes sugerem que vários organismos não-alvo, de abelhas a mamíferos, apresentam uma grande variedade de efeitos tóxicos após a exposição aos pesticidas a pesticidas, incluindo alterações de comportamento, no desenvolvimento e na reprodução. Entre os mamíferos, os morcegos geralmente são negligenciados entre os estudos ecotoxicológicos, embora desempenhem importantes papéis ecológicos e econômicos nos ecossistemas florestais e na agricultura por meio do controle de dispersão de sementes e de populações de insetos. Considerando sua ampla variedade de hábitos alimentares, eles estão expostos a poluentes ambientais através da contaminação de alimentos ou água, ou através do contato direto com a pele em suas áreas de descanso. Para entender melhor o risco que os agrotóxicos representam para as populações de morcegos, compilamos estudos que investigaram os principais efeitos toxicológicos de agrotóxicos em morcegos, visando à discussão sobre os riscos ambientais associados ao uso de agrotóxicos.

Low energy reserves are associated with fasting susceptibility in Neotropical nectar bats Glossophaga soricina / Baixas reservas energéticas corporais estão associadas à susceptibilidade ao jejum da espécie Glossophaga soricina

Abstract Neotropical nectar-feeding bats consume large amounts of sugar and use most of their energy-rich diet directly from the bloodstream, suggesting an adaptation towards lower body energy reserves. Here we tested the hypothesis that bats Glossophaga soricina spare the energy costs of storing energy reserves, even if this would represent a risky susceptibility during fasting. Blood glucose concentrations in 18 h fasted bats showed a 40% decrease. Breast muscle and adipose tissue lipids, as well as carcass fatty acids and liver glycogen, were also decreased following fasting. The inability to keep normoglycemia following a short-term fasting (i.e. 28 h) confirm that nectar bats invest little on storing energy reserves and show a severe fasting susceptibility associated to this pattern. Our study also support the general hypothesis that evolutionary specializations towards nectar diets involve adaptations to allow a decreased body mass, which reduces the energy costs of flight while increases foraging time.

Resumo Morcegos nectarívoros que ocorrem na região Neotropical consomem grandes quantidades de carboidratos, e usam a energia obtida da dieta diretamente, a partir da glicose na circulação sanguínea. Esta adaptação sugere que morcegos nectarívoros tenham evoluído no sentido de apresentar adaptações fisiológicas que permitam o baixo armazenamento de reservas energéticas corporais. Nós testamos a hipótese de que morcegos Glossophaga soricina poupam o gasto energético envolvido com a formação de reservas energéticas teciduais, mesmo que isso represente uma arriscada suscetibilidade da espécie frente ao jejum. As concentrações de glicose apresentaram uma diminuição de 40% após 18 h de jejum. As concentrações de lipídios do músculo peitoral e do tecido adiposo, bem como as de ácidos graxos da carcaça e glicogênio hepático também diminuíram após 18 h de jejum. A incapacidade de manter a normoglicemia observada após o jejum de curto-prazo confirma que morcegos nectarívoros desta espécie não investem na formação de reservas energéticas, e apresentam, consequentemente, uma severa susceptibilidade ao jejum. Este estudo suporta a hipótese de que adaptações evolucionárias da espécie envolvem diminuição da massa corporal, reduzindo o custo energético do voo e aumentado o tempo de forrageamento.

Low energy reserves are associated with fasting susceptibility in Neotropical nectar bats Glossophaga soricina.

Neotropical nectar-feeding bats consume large amounts of sugar and use most of their energy-rich diet directly from the bloodstream, suggesting an adaptation towards lower body energy reserves. Here we tested the hypothesis that bats Glossophaga soricina spare the energy costs of storing energy reserves, even if this would represent a risky susceptibility during fasting. Blood glucose concentrations in 18 h fasted bats showed a 40% decrease. Breast muscle and adipose tissue lipids, as well as carcass fatty acids and liver glycogen, were also decreased following fasting. The inability to keep normoglycemia following a short-term fasting (i.e. 28 h) confirm that nectar bats invest little on storing energy reserves and show a severe fasting susceptibility associated to this pattern. Our study also support the general hypothesis that evolutionary specializations towards nectar diets involve adaptations to allow a decreased body mass, which reduces the energy costs of flight while increases foraging time.

CHARACTERIZATION AND PERFORMANCE TESTS OF A NEW OSL/TL PERSONAL DOSEMETER FOR INDIVIDUAL MONITORING.

We propose a personal dosemeter based on the combination of thermoluminescence (TL) and optically stimulated luminescence (OSL) detectors employing the advantages of both techniques. The new OSL/TL dosemeter using a badge manufactured in a 3D printer was tested for assessment of photon doses in simulated and actual situations of exposure. Additionally, Brazilian national performance tests adapted to the new dosemeter were run as well as the performance tests of international standards on the passive dosimetry systems. The results showed the advantages of combined OSL and TL techniques when using the three different configurations of detector combination, Al2O3/BeO, BeO/CaSO4 and Al2O3/LiF. The dosemeter allowed corrections for radiation energy without the necessity of attenuation filters, the evaluation of single and accumulated doses and the triple check of the dose values. Further, the performance tests were consistent with national and international requirements, showing the viability of application of the new dosemeter to the assessment of equivalent doses.

Synthesis, characterization and photocatalytic properties of nanostructured CoFe2O4 recycled from spent Li-ion batteries.

In this study, cobalt (Co) was recycled from spent lithium ion batteries (LIBs) and used to synthesize cobalt ferrite (CoFe2O4-LIBs), which was applied as a catalyst for heterogeneous photo Fenton reactions that discolored methylene blue (MB) dye. The co-precipitation method was used to synthesize CoFe2O4-LIBs and CoFe2O4-R nanoparticles with spinel structures using as raw materials of the LIB cathodes and commercial reagents. X-ray diffraction (XRD) identified the formation of spinel-type CoFe2O4, which formed clusters that could be seen under scanning electron microscopy (SEM) analysis and nanometric particles seen under transmission electron microscopy (TEM). Inductively Coupled Plasma Optical Emission Spectrometer (ICP OES) analysis was used to determine the concentrations of metals present in the ferrite, which reached 6.5% (w/w) of Co. The optimal conditions for discoloring the dye were evaluated using a factorial design. Using CoFe2O4 as a catalyst, the best conditions for catalytic reaction were pH 3, 30.0 mg of catalyst, and 8.0 mL of H2O2 73% (v/v). Discoloration efficiencies of 87.3% and 87.7% were obtained from CoFe2O4-R and CoFe2O4-LIBs, respectively. Therefore, CoFe2O4-LIBs proved to be an efficient catalyst for discoloring MB dye using heterogeneous photo-Fenton reactions. This work is of scientific, social, economic, and environmental interest. It investigates the process of synthesizing,characterizing CoFe2O4LIBs and the efficiency of degrading MB dye, subjects that have economic and environmental, and therefore, social interest. The work has scientific interest particularly because of the correlation between the structure of the recycled material and its catalytic properties.

Pharyngeal Residue and Aspiration and the Relationship with Clinical/Nutritional Status of Patients with Oropharyngeal Dysphagia Submitted to Videofluoroscopy.

OBJECTIVES: The aim of this study was to investigate the association between the videofluoroscopic (VFS) signs of impaired efficacy (pharyngeal residue) and safety (aspiration) swallowing and the clinical/nutritional status of patients with suspect of dysphagia. DESIGN: A cross-sectional study was conducted with patients submitted to videofluoroscopy. SETTING AND PARTICIPANTS: Data of 76 patients were analyzed between March 2011 and December 2014. MEASUREMENTS: The clinical history and VFS exams of patients ≥ 38 years were retrospectively analyzed. RESULTS: 88% patients presented Oropharyngeal Dysphagia (OD), 44.7% presented laryngeal penetration and 32% presented aspiration. 78% patients presented pharyngeal residue. Aspiration was associated with Head Neck Cancer (HNC) [Prevalence Ratio (PR): 2.27, p = 0.028] and cardiovascular disease (PR 1.96, p = 0.027). Underweight [Body Mass Index < 18.5 kg/m2] was not associated with the presence of aspiration. Underweight patients with OD had a higher prevalence rate of pharyngeal residue than those normally nourished (100% vs. 78%) (PR 1.34, p = 0.011). Pharyngeal residue was associated with male sex (PR 1.32, p = 0.040), neurodegenerative disease (PR 1.57, p = 0.021), stroke (PR 1.62, p = 0.009), cerebral palsy (PR 1.76, p = 0.006) and HNC (PR 1.73, p = 0.002). CONCLUSION: In the present study, neurologic diseases, HNC, male sex and underweight were associated to impaired swallowing efficacy. Underweight, independently of the other variables, was not associated with impaired swallowing safety.

How do pesticides affect bats? A brief review of recent publications

Abstract Increased agricultural production has been increased use of pesticides worldwide, which poses a threat to both human and environmental health. Recent studies suggest that several non-target organisms, from bees to mammals, show a wide variety of toxic effects of pesticides exposure, including impaired behavior, development and reproduction. Among mammals, bats are usually a neglected taxon among ecotoxicological studies, although they play important ecological and economical roles in forest ecosystems and agriculture through to seed dispersal and insect population control. Considering their wide variety of food habits, bats are exposed to environmental pollutants through food or water contamination, or through direct skin contact in their roosting areas. In order to better understand the risk posed by pesticides to bats populations, we compiled studies that investigated the main toxicological effects of pesticides in bats, aiming at contributing to discussion about the environmental risks associated with the use of pesticides.

Resumo O aumento da produção agrícola tem levado ao aumento do uso de pesticidas em todo o mundo, o que representa uma ameaça para a saúde humana e ambiental. Estudos recentes sugerem que vários organismos não-alvo, de abelhas a mamíferos, apresentam uma grande variedade de efeitos tóxicos após a exposição aos pesticidas a pesticidas, incluindo alterações de comportamento, no desenvolvimento e na reprodução. Entre os mamíferos, os morcegos geralmente são negligenciados entre os estudos ecotoxicológicos, embora desempenhem importantes papéis ecológicos e econômicos nos ecossistemas florestais e na agricultura por meio do controle de dispersão de sementes e de populações de insetos. Considerando sua ampla variedade de hábitos alimentares, eles estão expostos a poluentes ambientais através da contaminação de alimentos ou água, ou através do contato direto com a pele em suas áreas de descanso. Para entender melhor o risco que os agrotóxicos representam para as populações de morcegos, compilamos estudos que investigaram os principais efeitos toxicológicos de agrotóxicos em morcegos, visando à discussão sobre os riscos ambientais associados ao uso de agrotóxicos.

Seasonal variation of energy reserves and reproduction in neotropical free-tailed bats Molossus molossus (Chiroptera: Molossidae).

Seasonal variation is a key factor regulating energy metabolism and reproduction in several mammals, including bats. This study aimed to track seasonal changes in the energy reserves of the insectivorous bat Molossus molossus associated with its reproductive cycle. Adult males were collected during the four neotropical annual seasons in Viçosa - MG, Brazil. Blood and tissues were collected for metabolic analysis and testes were removed for histology and morphometry. Our results show that liver and breast muscle glycogen concentrations were significantly lower in winter. The adiposity index was significantly higher in the fall compared to winter and spring. Seminiferous tubules were greater in diameter in animals captured in fall and winter, indicating a higher investment in spermatic production during these seasons. The percentage of Leydig cells was higher in summer compared to fall and winter. We suggest that M. molossus presents a type of seasonal reproduction with two peaks of testicular activity: one in fall, with higher sperm production (spermatogenesis), and another in summer, with higher hormone production (steroidogenesis). The metabolic pattern may be associated with reproductive events, especially due to the highest fat storage observed in the fall, which coincides with the further development of the seminiferous tubules.

Short-term effects of a spinosyn's family insecticide on energy metabolism and liver morphology in frugivorous bats Artibeus lituratus (Olfers, 1818).

A new class of insecticide derived from fermentation of Sacharopolyspora spinosa - spinosad, has been indicated as being of low toxicity and a natural alternative to classical pesticides. In order to elucidate several aspects related to the morphophysiological changes induced by spinosad in Artibeus lituratus, the effects of a seven-day administration on plasma glucose, glycogen, protein and lipid concentrations were evaluated, and possible changes in liver cells were examined by histological analysis. Animals were fed with spinosyn-contaminated fruit through immersion in a solution. Data reporting on metabolism revealed a decrease in hind limb muscle lipid concentration in the treated group. Morphological analysis indicated a significant increase in liver cell diameter in treated animals compared to the control group. This study indicates that spinosyn, used at its recommended dose, does not affect general energy metabolism in A. lituratus but may affect some ultrastructural characteristics of liver cells.

Energy reserves of Artibeus lituratus (Chiroptera: Phyllostomidae) in two areas with different degrees of conservation in Minas Gerais, Brazil.

Forest fragmentation associated with the expansion of human development is a phenomenon that occurs worldwide. Studies reveal that there have been both a decline in species diversity and a decrease in Neotropical bat population size because of habitat loss. The aim of this study was to investigate whether human action has been affecting the food availability to wildlife species, which could impact the storage of body energy reserves. For this purpose, fruit-eating bats (Artibeus lituratus) were collected in two areas in Minas Gerais state, Brazil. The concentrations of plasma glucose, as well as glycogen, lipids and protein in liver in muscles were performed, in addition to adipose tissue weight and carcass fatty acids. Our results indicate that fat reserves were significantly lower in most tested tissues (muscle of the hindlimbs, breast muscles, adipose tissue and carcass) in animals collected in the region with a higher degree of human disturbance. The other parameters showed no significant differences in the groups collected at different locations. In conclusion, we suggest that human action on the environment may be affecting the storage of body fat energy reserves of this species during the autumn, particularly in metropolitan region areas of Belo Horizonte, MG - Brazil, requiring special attention to the species conservation.

Fontes de óleos vegetais em dietas para acará-bandeira (Pterophyllum scalare, Cichlidae): crescimento e tolerância térmica / Vegetable oil sources in diets for freshwater angelfish (Pterophyllum scalare, Cichlidae): growth and thermal tolerance

The influence of fatty acid composition of the diets on the productive performance and on cold and heat tolerance of juvenile freshwater angelfish (Pterophyllum scalare), in three different phases, was studied. Phase I studied the productive performance of freshwater angelfish in a completely randomized experimental design with four treatments, canola, linseed, olive and soybean oils and four replicates during 50 days using 192 fish in 16 aquaria. Phase II studied the cold tolerance of juvenile freshwater angelfish using 72 juvenile freshwater angelfish, coming from phase I and maintained in 12 aquaria climatized chamber. The temperature was reduced 1ºC per day, until the observation of 100 percent fish mortality. Phase III, it was studied the heat tolerance of juvenile freshwater angelfish employing an identical procedure to phase II, but with a daily increase of 1ºC. Significant differences (P>0.05) were not observed for any parameters evaluated. Thus, it was concluded that the type of vegetable oil (canola, linseed, olive and soybean) used as a diet supplement did not affect the productive performance, nor the tolerance to cold and heat, of juvenile freshwater angelfish.

Avaliou-se a influência da suplementação de lipídeos na dieta, com diferentes composições de ácidos graxos, sobre o desempenho produtivo e tolerância ao frio e ao calor de juvenis de acará-bandeira (Pterophyllum scalare). O experimento foi realizado em três fases. Na fase um avaliou-se o desempenho produtivo dos peixes em delineamento inteiramente ao acaso com quatro tratamentos - óleos de canola, linhaça, oliva e soja - e quatro repetições, durante 50 dias usando 192 peixes distribuídos em 16 aquários. Na segunda fase, avaliou-se a tolerância ao frio, usando 72 peixes, procedentes da fase um, distribuídos em 12 aquários e mantidos em câmara climatizada. A temperatura foi reduzida de 1ºC por dia até a observação de 100 por cento de mortalidade dos peixes. Na fase três, avaliou-se a tolerância ao calor com procedimentos semelhantes aos da fase dois, porém a temperatura foi elevada 1ºC por dia. Não foram observadas diferenças significativas (P>0,05) para os parâmetros avaliados. Conclui-se que a suplementação de óleos vegetais nas dietas não inferiu no desempenho produtivo e na tolerância ao frio e ao calor de juvenis de acará-bandeira.

Energy metabolism and fasting in male and female insectivorous bats Molossus molossus (Chiroptera: Molossidae).

Metabolic adaptations induced by 24 and 48 hours of fasting were investigated in male and female insectivorous bats (Molossus molossus Pallas, 1766). For this purpose, plasma glucose, non esterified fatty acids (NEFA), glycogen, protein and lipids concentrations in liver and muscles were obtained. Data presented here demonstrate that fed bats showed plasma glucose levels similar to those reported for other mammal species. In response to fasting, glycemia was decreased only in 48 hours fasted females. Plasma NEFA levels were similar in both sexes, and did not exhibit any changes during fasting. Considering the data from energy reserve variations, fed females presented an increased content of liver glycogen as well as higher breast muscle protein and limbs lipids concentrations, compared to fed males. In response to fasting, liver and muscle glycogen levels remained unchanged. Considering protein and lipid reserves, only females showed decreased values following fasting, as seen in breast, limbs and carcass lipids and breast muscle protein reserves, but still fail to keep glucose homeostasis after 48 hours without food. Taken together, our data suggest that the energy metabolism of insectivorous bats may vary according to sexual differences, a pattern that might be associated to different reproduction investments and costs between genders.

Energy metabolism and fasting in male and female insectivorous bats Molossus molossus (Chiroptera: Molossidae) / Metabolismo energético e resposta ao jejum em morcegos insetívoros Molossus molossus (Chirpotera: Molossidae)

Metabolic adaptations induced by 24 and 48 hours of fasting were investigated in male and female insectivorous bats (Molossus molossus Pallas, 1766). For this purpose, plasma glucose, non esterified fatty acids (NEFA), glycogen, protein and lipids concentrations in liver and muscles were obtained. Data presented here demonstrate that fed bats showed plasma glucose levels similar to those reported for other mammal species. In response to fasting, glycemia was decreased only in 48 hours fasted females. Plasma NEFA levels were similar in both sexes, and did not exhibit any changes during fasting. Considering the data from energy reserve variations, fed females presented an increased content of liver glycogen as well as higher breast muscle protein and limbs lipids concentrations, compared to fed males. In response to fasting, liver and muscle glycogen levels remained unchanged. Considering protein and lipid reserves, only females showed decreased values following fasting, as seen in breast, limbs and carcass lipids and breast muscle protein reserves, but still fail to keep glucose homeostasis after 48 hours without food. Taken together, our data suggest that the energy metabolism of insectivorous bats may vary according to sexual differences, a pattern that might be associated to different reproduction investments and costs between genders.

As adaptações metabólicas induzidas pelo jejum foram investigadas em morcegos insetívoros machos e fêmeas (Molossus molossus Pallas, 1766) alimentados e submetidos ao jejum por 24 e 48 horas. Para este propósito, análises plasmáticas de glucose, ácidos graxos livres, glicogênio, proteína e lipídios do fígado e músculos foram analisados. Os dados obtidos demonstraram que o nível de glicose plasmática em morcegos alimentados foi similar ao apresentado por outras espécies de mamíferos. No entanto, em resposta ao jejum, a glicemia de fêmeas diminuiu significativamente após 48 horas, enquanto os níveis circulantes de machos permaneceram constantes. Os níveis de ácidos graxos não esterificados no plasma foram similares em ambos os sexos, e não houve mudança durante o jejum. Em relação às reservas energéticas, fêmeas alimentadas apresentaram maior teor de glicogênio no fígado, de proteína armazenada no músculo peitoral e lipídios nos músculos dos membros anteriores e posteriores, em comparação aos machos alimentados. Em resposta ao jejum, somente as fêmeas mostraram diminuição de algumas reservas energéticas, como a reserva lipídica dos músculos dos membros anteriores e posteriores, da carcaça e da reserva proteica do músculo peitoral. Apesar desta mobilização, as fêmeas, diferentemente dos machos, demonstraram uma incapacidade de manter a homeostase da glicose após 48 horas sem o alimento. Nossos dados sugerem que o metabolismo energético de morcegos insetívoros varia de acordo com o sexo, sendo que o padrão metabólico pode estar associado a diferenças de custo energético no investimento reprodutivo entre machos e fêmeas.

Seasonal variation and food deprivation in common vampire bats (Chiroptera: Phyllostomidae)

The aim of this study was to investigate the effects of seasonal variation and fasting on fat reserves of the common vampire bat Desmodus rotundus. Plasma free fatty acids (FFA), along with lipid content of the liver and muscles, and fatty acids from the carcass were obtained from bats fed bovine blood and from whom food was subsequently withheld for 24 and 48 h. Animals were caught during both dry and rainy seasons. In general, fat tissue stores were not significantly influenced by seasonal variation. Lipid content of liver, muscles, and carcass decreased during some food deprivation periods, although the concomitant increase expected in plasma FFA was not observed. Lipid metabolism is hypothesized as being continued by the tissues themselves. In addition, free access to food sources (e.g., domestic livestock) throughout the year is believed to contribute to the low seasonal variations in fat reserves observed in the common vampire bat.

Os efeitos da variação sazonal e do jejum sobre as reservas lipídicas do morcego vampiro comum (Desmodus rotundus) foram investigadas a fim de se estabelecer o padrão do metabolismo de lipídios da espécie e possíveis alterações sazonais. Foram determinadas as concentrações de Acidos Graxos Livres (AGL) e o conteúdo lipídico no fígado, músculos e na carcaça de animais alimentados (sangue bovino) e jejuados por 24 e 48 h, capturados durante as estações seca e chuvosa. Em geral, os depósitos lipídicos teciduais não apresentaram variações significativas em resposta às diferentes estações. As reservas de gordura diminuíram, no entanto, em resposta ao jejum, apesar de não ter sido observado nenhum aumento simultâneo dos AGL no plasma, aumento que normalmente indica mobilização lipídica. O metabolismo lipídico nestes tecidos parece importante para as necessidades energéticas dos próprios tecidos. Fatores como abundância e facilidade de acesso às presas (bovinos) podem estar contribuindo para a baixa variabilidade sazonal das reservas lipídicas teciduais.

Seasonal variation and food deprivation in common vampire bats (Chiroptera: Phyllostomidae).

The aim of this study was to investigate the effects of seasonal variation and fasting on fat reserves of the common vampire bat Desmodus rotundus. Plasma free fatty acids (FFA), along with lipid content of the liver and muscles, and fatty acids from the carcass were obtained from bats fed bovine blood and from whom food was subsequently withheld for 24 and 48 h. Animals were caught during both dry and rainy seasons. In general, fat tissue stores were not significantly influenced by seasonal variation. Lipid content of liver, muscles, and carcass decreased during some food deprivation periods, although the concomitant increase expected in plasma FFA was not observed. Lipid metabolism is hypothesized as being continued by the tissues themselves. In addition, free access to food sources (e.g., domestic livestock) throughout the year is believed to contribute to the low seasonal variations in fat reserves observed in the common vampire bat.

Dose measurements in chest diagnostic X rays: adult and paediatric patients.

This survey was carried out in the state of São Paulo, Brazil. The health services located in the state perform approximately 321 radiological examinations per 1000 inhabitants. A representative sample of 200 health services was selected using sampling techniques, and a postal dosimetric kit was sent to each one who agreed to participate. The kit evaluates entrance surface dose (ESD), making use of thermoluminescence dosemeters attached to the skin of patients. The radiographic technique employed and some physical data of patients were also gathered. In this stage of the survey, only chest examinations, projections AP, PA and LAT, were evaluated. A total of 917 ESD values were measured, which correspond to 588 patients and 74 examination rooms. The ESD to patients were analysed according to weight and age. Groups of standard patients (children and adults) were selected, and reference doses were determined. Large variations of ESD were observed, indicating that much can be done in order to reduce the patient doses by changing the technical parameters. Moreover, the results of ESD in paediatric radiology point to the necessity of special attention in the practice of radiological examinations in this age group.

Metabolic responses induced by fasting in the common vampire bat Desmodus rotundus.

This study explored the effects of fasting on body fuel mobilization in the common vampire bat (Desmodus rotundus) fed a high-protein diet (bovine blood). An uncommon fragility during food deprivation has been reported for this species to the point of untimely deaths after only 2-3 nights of fasting. The immediate biochemical responses to fasting, however, have not been established. Thus, blood glucose, plasma FFA, glycogen, protein, and fat concentrations in the liver and muscles were determined in fed and 24-, 48- and 72 h-fasted individuals. The results indicate that D. rotundus is unable to maintain adequate levels of blood glucose during fasting, probably due to low tissue stores of energy fuels or difficulty in mobilizing them. Other factors may play an important role in this species abundance, such as the previously reported behavior of reciprocal blood regurgitation.

An overview of doses to patients and irradiation conditions of diagnostic chest x ray examinations carried out in hospitals of the City of São Paulo, Brazil.

Recently the Brazilian health organisation published information conceming the number of hospitals, details of radiological equipment and frequency of medical examinations in the country. The information concerning the city of São Paulo is compiled here, complemented by a survey of absorbed doses to patients undergoing the most frequent examination: chest radiographs (postero-anterior (PA) and lateral (LAT) projections), as well as the physical parameters employed (tube voltage, current-time product, focus-film distance, field size). To collect the data, a sample of 12 hospitals (a representative sample of the 199 located in the city) was chosen, totalling 27 X ray machines. An anthropomorphic phantom was irradiated to simulate the patient. Absorbed doses were determined with thermoluminescence dosemeters placed in the phantom, externally and internally. Mean values of entrance surface dose (ESD) for PA and LAT projections were 0.22 mGy (from 0.07 to 0.61 mGy) and 0.98 mGy (from (1.30 to 4.01 mGy), respectively. The average organ doses per complete examination (PA and LAT) were 0.15 and 0.24 mGy to thyroid and lung, respectively. The thyroid was thus in the primary beam in many cases. The large variation in the ESD and organ doses indicates that much can be done in order to reduce the patient doses by adequate changes of physical parameters, without loss of image quality.