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Experimental hendra virus infectionin pregnant guinea-pigs and fruit Bats (Pteropus poliocephalus).

Antibodies to Hendra virus (HeV) have been found in a high percentage of fruit bats (Pteropus spp.) in Australia, indicating a possible reservoir for the virus. The aim of the experiments reported here was to investigate transplacental infection as a possible mode of transmission of the virus in fruit bats and other animals. In a first experiment, 18 pregnant guinea-pigs in the mid-stage of gestation were inoculated with HeV, as an experimental model in a conventional laboratory animal. Nine developed HeV disease as confirmed by viral isolation, histopathology and immunohistochemistry. In five of the nine clinically affected guinea-pigs there was necrosis and strong positive immunostaining in the placentas in an indirect immunoperoxidase (IPX) test for HeV antigen. One of these five guinea-pigs aborted and HeV was isolated from its three fetuses, one of which was also positive to the IPX test. In three other sick guinea-pig dams, virus was isolated from fetuses, and there was positive immunostaining in two of the latter. In a second experiment, four fruit bats were inoculated with a similar dose of HeV. (A further four guinea-pigs inoculated at the same time developed severe disease, indicating adequate virulence.) Two bats were killed at 10 days post-inoculation and two were killed at 21 days. In these bats, no overt clinical disease was observed, but subclinical disease occurred, as indicated by viral isolation, seroconversion, vascular lesions and positive immunostaining. Transplacental transmission was indicated by positive immunostaining in two placentas and confirmed by isolation of virus from one of the associated fetuses.

Animals↗
PubMed1992

Analysis of nuclear 3,3',5-triiodothyronine receptor in the brown adipose tissue (BAT) of the postnatal lamb.

Postnatal thermogenesis in sheep is associated with increased sympathoadrenal activities, a T3 surge and an enhanced brown adipose tissue (BAT) type II 5'-monodeiodinating (5'-MDI) activity. The latter peaks 3-4 days after birth and is known to be important in generating intracellular T3 for nuclear receptor binding. In order to further investigate the mechanism(s) responsible for neonatal thermogenesis, thyroid hormone nuclear receptor (T3NR) binding characteristics were quantified in lamb BAT from newborn (NB) to 30d of postnatal age. Maximal binding capacities (MBC, mean +/- SEM fmoles T3/mg DNA) in BAT showed a decrease as studied by ANOVA during the first 11 days (NB to 1d, 148 +/- 24 [N = 5, p < 0.01, cf. 3-5d group]; 3-5 d, 61 +/- 5.5 [N = 5]; 10-11d, 72 +/- 9.1 [N = 4]). Afterwards, MBC increased at 30d (196 +/- 32, N = 4, p less than 0.01, cf. 3-5d group). BAT T3NR binding affinities (10(9) M-1) were comparable in all age groups studied (NB-1d, 2.8 +/- 0.3; 3-5d, 3.4 +/- 0.3; 10-11d, 4.0 +/- 1.1; 30d, 2.4 +/- 0.4). The data suggest that the postnatal surge in T3 and type II 5'-MDI is accompanied with a concurrent decrease in MBC of BAT T3NR. The latter may represent a down-regulation of T3NR presumably in an attempt to regulate the overall effect of thyroid hormone in neonatal thermogenesis.

Adipose Tissue, Brown↗
PubMed2001

Bat predation on nocturnally migrating birds.

Bat predation on birds is a very rare phenomenon in nature. Most documented reports of bird-eating bats refer to tropical bats that occasionally capture resting birds. Millions of small birds concentrate and cross over the world's temperate regions during migration, mainly at night, but no nocturnal predators are known to benefit from this enormous food resource. An analysis of 14,000 fecal pellets of the greater noctule bat (Nyctalus lasiopterus) reveals that this species captures and eats large numbers of migrating passerines, making it the only bat species so far known that regularly preys on birds. The echolocation characteristics and wing morphology of this species strongly suggest that it captures birds in flight.

Animals↗
PubMed2001

Diet, phylogeny, and basal metabolic rate in phyllostomid bats.

Aside from the pervasive effects of body mass, much controversy exists as to what factors account for interspecific variation in basal metabolic rates (BMR) of mammals; however, both diet and phylogeny have been strongly implicated. We examined variation in BMR within the New World bat family Phyllostomidae, which shows the largest diversity of food habits among mammalian families, including frugivorous, nectarivorous, insectivorous, carnivorous and blood-eating species. For 27 species, diet was taken from the literature and BMR was either measured on animals captured in Brazil or extracted from the literature. Conventional (nonphylogenetic) analysis of covariance (ANCOVA), with body mass as the covariate, was first used to test the effects of diet on BMR. In this analysis, which assumes that all species evolved simultaneously from a single ancestor (i.e., a "star" phylogeny), diet exerted a strong effect on mass-independent BMR: nectarivorous bats showed higher mass-independent BMR than other bats feeding on fruits, insects or blood. In phylogenetic ANCOVAs via Monte Carlo computer simulation, which assume that species are part of a branching hierarchical phylogeny, no statistically significant effect of diet on BMR was observed. Hence, results of the nonphylogenetic analysis were misleading because the critical values for testing the effect of diet were underestimated. However, in this sample of bats, diet is perfectly confounded with phylogeny, because the four dietary categories represent four separate subclades, which greatly reduces statistical power to detect a diet (= subclade) effect. But even if diet did appear to exert an influence on BMR in this sample of bats, it would not be logically possible to separate this effect from the possibility that the dietary categories differ for some other reason (i.e., another synapomorphy of one or more of the subclades). Examples such as this highlight the importance of considering phylogenetic relationships when designing new comparative studies, as well as when analyzing existing data sets. We also discuss some possible reasons why BMR may not coadapt with diet.

Journal Article↗
PubMed1980

Synthesis of DNA as shown by the deoxyuridine suppression test is normal in the vitamin B12-deficient fruit bat (Rosettus Aegyptiacus).

1. DNA synthesis in the bone marrow and lymphocytes of the vitamin B12-deficient fruit bat (Rosettus Aegyptiacus) has been studied via the deoxyuridine (dU) suppression test. 2. In contrast to vitamin B12 deficiency in man, the dU suppression test was not abnormal in the vitamin B12-deficient bat, and this correlates with the reported finding that the latter does not develop megaloblastic anaemia. 3. The protection of haemopoiesis from vitamin B12 deficiency in the bat is probably related to the presence in the bat of separate pools of methylfolate and tetrahydrofolate, which enables the bat to overcome the trapping of methylfolate attendant on vitamin B12 deficiency. 4. These results confirm the central role of the vitamin B12 and folate-dependent pathway of de novo synthesis of DNA in the pathogenesis of vitamin B12-deficient megaloblastic anaemia.

Animals↗
PubMed2000

A review of batting in men's cricket.

In this review, we critically evaluate the scientific research into the morphology and physiology of cricket batsmen. We consider all aspects of the motor control of this skill, in the context of research into dynamic interceptive actions, the biomechanics (kinematics and kinetics) of the various phases of batting strokes and injuries to batsmen. Some attention is also devoted to batting equipment and to psychological factors in batting. Because of the lack of published scientific research into women's cricket, this review focuses on the men's game and covers research on batsmen of various playing standards. For the future, we see as a high priority research into injury mechanisms, rather than simple injury statistics, and the role of cricket equipment design in injury prevention. A second priority is for multi- or inter-disciplinary research, linking the biomechanics of batting to the underlying motor control of the movements and the effect of environmental information. Biomechanical studies of the variability of the batsman's movements are needed, and these should be related to the compensatory variability proposal of ecological psychology. Clearly, there is also a need for scientific research into batting in women's cricket, which has been inadequately researched to date.

Anthropometry↗
PubMed2005

Non-parametric entrainment by natural twilight in the microchiropteran bat, Hipposideros speoris inside a cave.

The study aimed to determine the influence of repeated natural dawn and dusk twilight pulses in entraining the circadian flight activity rhythm of the microchiropteran bat, Hipposideros speoris, free-running in constant darkness in a natural cave. The bats were exposed to repeated dawn or dusk twilight pulses at eight circadian phases. All bats exposed to dawn twilight pulses were entrained by advancing transients, and the stable entrainment was reached when the onset of activity occurred about 12 h before the lights-on of the pulses, irrespective of the initial phase at which the bats were exposed to twilight. All bats exposed to dusk twilight pulses, however, were entrained by delaying transients, and the stable entrainment was reached when the onset of activity occurred about 1.6 h after the lights-on of the pulses. The entrainment caused by dawn and dusk twilight pulses is discussed in the context of the postulated two photoreceptors: the short wavelength sensitive (S) photoreceptors mediating entrainment via dusk twilight, and the medium wavelength sensitive (M) photoreceptors mediating entrainment via dawn twilight.

Animals↗
PubMed2001

Renal structure in neotropical bats: using stable isotopes to explore relationships between diet and morphology.

The relationship between kidney structure and diet was examined in several species of bats from the tropics. The trophic level of the bats was determined by their stable nitrogen isotopic composition (delta15 N). The results indicate that the relative thickness of the renal medulla is directly related to the trophic level of the bats. Additionally, we also determined the relationship between body mass and kidney structure. Relative medullary thickness was reciprocally related to body mass in animalivorous bats but no relationship was found in phytophagous bats. Stable isotope analysis provided a quantitative approximation of diet to test its relationship with kidney structure.

Animals↗
PubMed2001

An architectonic comparison of the ventrobasal complex of two megachiropteran and one microchiropteran bat: implications for the evolution of Chiroptera.

The architectonic features of the thalamic ventrobasal complex (Vb) of two species of Megachiropteran (Grey-headed flying fox, Pteropus poliocephalus, and the Eastern tube-nosed bat, Nyctimene robinsoni) are compared with those of a Microchiropteran (Australian ghost bat, Macroderma gigas). The somatosensory system was chosen for comparison as it represents a sensory system that has undergone analogous modifications in both Chiropteran lineages (the evolution of the wing). The components of Vb were examined as there are taxon-specific features in this region of the brain. Within the Megachiropteran Vb, four subnuclei were recognized: the ventral posterior medial (VPM), the ventral posterior lateral (VPL), the ventral posterior inferior (VPI), and the basal ventral medial (VMb). In the ghost bat only VPM and VPL were identified with certainty. No VPI was evident in the ghost bat, however a putative VMb was observed. Vb of the ghost bat also lacked the arcuate lamina, which distinguishes VPM from VPL in the Megachiropterans and many other mammals. These taxon-specific differences lend support to the proposal that the order Chiroptera has a diphyletic origin.

Animals↗
PubMed2006

Ammonia excretion increased and urea excretion decreased in urine of a new world nectarivorous bat with decreased nitrogen intake.

We determined the effect of water and nitrogen intake on nitrogenous waste composition in the nectarivorous Pallas's long-tongued bat Glossophaga soricina (Phyllostomidae) to test the hypothesis that bats reduce excretion of urea nitrogen and increase the excretion of ammonia nitrogen as nitrogen intake decreases and water intake decreases. Because changes in urine nitrogen composition are expected only in animals whose natural diets are low in nitrogen and high in water content, we also measured maintenance nitrogen requirements (MNR). We hypothesized that, similar to other plant-eating vertebrates, nectarivorous bats have low MNR. Our nitrogen excretion hypothesis was partly proved correct. There was an increase in the proportion of N excreted as ammonia and a decrease in the proportion excreted as urea in low-nitrogen diets. The proportion of N excreted as ammonia and urea was independent of water intake. Most individuals were ureotelic (n = 28), and only a few were ureo-ammonotelic (n = 3) or ammonotelic (n = 2). According to our nitrogen requirement hypothesis, apparent MNR (60 mg kg(-0.75) d(-1)) and truly digestible MNR (54 mg N kg(-0.75) d(-1)) were low. A decrease in urea excretion in low-nitrogen diets may result from urea recycling from liver to the gut functioning as a nitrogen salvage system in nectarivorous bats. This mechanism probably contributes to the low MNR found in Pallas's long-tongued bats.

Ammonia↗
PubMed2006

The influence of ambient temperature and the energy and protein content of food on nitrogenous excretion in the Egyptian fruit bat (Rousettus aegyptiacus).

The diets of frugivorous and nectarivorous vertebrates contain much water and generally have high energy but low protein contents. Therefore, we tested the prediction that to save energy under conditions of high energy demands and high water intake, frugivorous Egyptian fruit bats (Rousettus aegyptiacus) will increase both the absolute quantity and the proportion of ammonia in their urine. We also examined whether such changes occur when protein intake is low and water intake is high. We did three feeding trials. In trials 1 and 2, bats were fed one of four liquid diets containing constant soy protein concentrations but varying in sucrose concentration and were kept at ambient temperatures (T(a)) of 30 degrees Celsius and 12 degrees Celsius, respectively. In trial 3, bats were kept at Ta=12 degrees Celsius and fed one of four liquid diets with equal sucrose concentrations but varying protein concentrations. In trial 1, food intake at a sucrose concentration of 256 mmol/kg H(2)O was initially high but decreased to a constant rate with further increases in sucrose concentration, while in trial 2, food intake decreased exponentially with increasing sucrose concentration. As predicted, at 12 degrees Celsius with varying sucrose concentration, both the absolute quantity and the fraction of ammonia in the bats' urine increased significantly with food intake (P<0.02), while the absolute quantity of urea and the fraction of urea nitrogen excreted decreased significantly with food intake (P<0.03). Varying sucrose concentration had no significant effect on nitrogen excretion at Ta=30 degrees Celsius. Varying protein concentration had no significant effect on nitrogen excretion at Ta=12 degrees Celsius. We suggest that Egyptian fruit bats can increase ammonia excretion in response to increased energetic demands, and we calculate that they can save energy equal to approximately 2% of their daily metabolic rate by doing so.

Animals↗
PubMed2001

Apoptosis-related gene and protein expression in human lymphoma xenografts (Raji) after low dose rate radiation using 67Cu-2IT-BAT-Lym-1 radioimmunotherapy.

Despite low radiation dose rates, radioimmunotherapy (RIT) has proven particularly effective in the treatment of malignancies, such as lymphoma. Apoptosis has been suggested to be a major mechanism for cell death from continuous low-dose rate radiation from radioimmunotherapy. The goal of this study was to examine Raji lymphoma xenografts for induction of apoptosis and modulation of apoptosis-related gene and protein expression in response to 67Cu-2IT-BAT-Lym-1 RIT. In preclinical and clinical trials, 67Cu-2IT-BAT-Lym-1 has shown an exceptionally long tumor residence time associated with substantial cumulated radiation doses. The Raji model mirrors human lymphomas that have mutant p53 and increased BCL2 expression. Untreated athymic BALB/c nu/nu mice and mice treated with 400 micrograms Lym-1, or 335-500 microCi 67Cu on less than 400 micrograms Lym-1 antibody, were observed for toxicity and response over 84 days. Subgroups of 4-5 mice were sacrificed at 3, 6 and 24 h after therapy so that tumors could be examined for poly(ADP-ribose) polymerase (PARP) and DNA ladder evidence for apoptosis and for BCL2, p53, p21, GADD45, TGF-beta 1 and c-MYC gene and protein expression. Untreated tumors had little evidence of apoptosis and Lym-1 had no effect on apoptosis or gene expression. 67Cu-2IT-BAT-Lym-1 RIT induced an overall response rate of 50% with tolerable toxicity, and 29% of the tumors were cured at cumulated tumor radiation doses of about 1800 cGy. Apoptosis was greatly increased in the RIT treated Raji xenografts as evidenced by cleavage of PARP to the characteristic 85 kD fragment at 3 and 6 h and by the DNA cleavage pattern. BCL2 gene and protein expression were substantially decreased at 3 and 24 h, respectively, after 67Cu-2IT-BAT-Lym-1 RIT despite only modest cumulated radiation doses (56 cGy at 3 h). Evidence for apoptosis preceded tumor regression by 4-6 days. In these therapy-resistant, human lymphoma tumors treated with 67Cu-2IT-BAT-Lym-1, apoptosis was convincingly demonstrated to be a major mechanism for the effectiveness of RIT and occurred by p53-independent mechanisms.

Animals↗
PubMed2004

The north-east-Brazilian Liana, Adenocalymna dichilum (Bignoniaceae) pollinated by bats.

BACKGROUND AND AIMS: Of the set of syndromes displayed by specialized (euphilic) flowers, adaptation to pollination by bats (chiropterophily) is the least known. Accumulated new evidence reveals that this pollination mode plays a considerable role in tropical communities, especially in the neotropics. One family in which bat-pollinated species are known in several genera is the Bignoniaceae. Here is reported, for the first time, bat pollination and floral ecology in Adenocalymna dichilum (tribe Bignonieae). METHODS: Floral features of this species growing in Bahia (north-east Brazil) indicated possible chiropterophily, which was subsequently confirmed by direct observation and from photographs of bat visits. Timing of anthesis and nectar parameters were monitored in the field, and floral morphology was investigated with fixed flowers. KEY RESULTS: One to two flowers open per night on the upright, simple racemes of A. dichilum during several weeks in a 'steady state' mode. The bilabiate, cream-coloured corollas are functional for only a single night and wilt during the following day. A stout corolla, with a musky odour, and a large nectary disc with large quantities of watery nectar also conform to the syndrome. Glossophaga soricina (Glossophaginae) visited and pollinated the flowers in a trap-lining manner. Whilst hovering, the bats put their heads into the corolla mouth for less than 1 s to feed, thereby effecting the transfer of pollen which is deposited on their backs. CONCLUSIONS: Adenocalymna, a New World genus comprising approx. 50 species, exhibits floral adaptive radiation including species pollinated by bees, birds and possibly moths. The discovery of chiropterophily in A. dichilum adds another facet to the array of floral syndromes represented in the genus.

Animals↗
PubMed2001

DNA variants of BAT-25 in Japanese, a locus frequently used for analysis of microsatellite instability.

BAT-25 is a DNA marker, intragenic to the c-kit protooncogene, assigned to 4q12, containing a polythymine tract, mostly repeats of 25 poly(T) (T25). The BAT-25 locus is frequently used in the analysis of microsatellite instability (MSI) in cancer tissues. The number of poly(T) repeats at BAT-25 is reported to be quasi-monomorphic and this property permits the easy identification of the MSI status. We report DNA variants of BAT-25, in one patient with hereditary nonpolyposis colorectal cancer presenting T21 and T25 alleles and another carrying T18 and T25 alleles in the analysis of 100 normal Japanese donors. Observed allelic frequencies were 0.5% for both T21 and T18 alleles. So far, DNA variants of BAT-25 locus have been reported in African Americans with relatively high frequencies, but not in Japanese.

Colorectal Neoplasms, Hereditary Nonpolyposis↗
PubMed2004

A morphological and immunohistochemical comparison of mammary tissues from the short-tailed fruit bat (Carollia perspicillata) and the mouse.

In the present study, mammary tissues from the fruit bat (Carollia perspicillata) and mouse (Mus musculus) were compared using histological and immunohistochemical methods. Because the female bat exhibits greater reproductive similarities to humans, it might provide a useful animal model for studying mammary physiology and disease with relevance to our own species. In lactating and recently lactating specimens, bat tissue had significantly fewer adipocytes and more collagenous connective tissue compared to the mouse. The proteins Stat5a, keratin 5, Npt2b, and E-cadherin were all similarly localized in mouse and bat mammary tissues taken from lactating animals. The present study demonstrates that whereas the epithelial compartment and the presence of differentiation markers are conserved between the mouse and bat, differences exist in the stromal compartment.

Animals↗
PubMed1985

Control of plasma sex steroid-binding protein (SBP) in the little brown bat: effects of thyroidectomy and treatment with L- and D-thyroxine on the induction of SBP in adult males.

The male little brown bat is a seasonally reproductive mammal that exhibits dramatic increases in plasma concentrations of sex steroid-binding protein (SBP) in the spring, following arousal from hibernation. Adult male bats, aroused prematurely from hibernation, were found to exhibit increases in plasma SBP titers that were comparable to those observed during normal spring arousal. To evaluate the role of the thyroid gland in the control of SBP in this species, plasma SBP concentrations were determined at weekly intervals in adult male bats that were either thyroparathyroidectomized (TRX) or sham operated (SHAM) after arousal from hibernation. Plasma SBP titers in SHAM males increased markedly within the first week after arousal and by 3 wk had reached levels 20-fold higher than those measured in hibernating controls. In contrast, plasma SBP values in the TRX animals did not increase significantly following arousal but were maintained at low basal levels throughout the experiment. The postarousal rise in SBP, which was blocked by TRX, was completely restored by implantation of either L- or D-thyroxine pellets. In male bats, TRX also hindered the normal postarousal atrophy of the sex accessory glands and resulted in attenuation of the postarousal increases in plasma testosterone concentrations. These effects of TRX were also prevented by treatment with thyroxine. Thus, the thyroid appears to play a significant role in the control of the postarousal rise of SBP in the little brown bat and may be an important factor in the regulation of reproductive function in this species.

Animals↗
PubMed2006

Bipolar anastomosis technique (BAT) enables "fast-to-do", high-quality venous end-to-end anastomosis in a new vascular model.

The interrupted suture technique is most commonly used for microsurgical venous anastomosis. Needle-stitch trauma and intraluminal suture, however, potentially cause vascular wall damage, thrombosis, intimal hyperplasia or even stenosis. Therefore, the present study aimed to show the feasibility and reliability of a modified cuff technique (bipolar anastomosis technique (BAT)) for venous end-to-end anastomosis in a new chicken throat vascular model. In ex vivo experiments, freshly resected chicken jugular veins (N = 96) were used to find ideal BAT time to current settings for venous end-to-end anastomosis. Thereafter, the left jugular vein of chickens (N = 40) was dissected in vivo and subsequently anastomosed using BAT. The quality of anastomosis was evaluated by Doppler sonography immediately, at two hours and at two, six, 12, 16, and 29 weeks after surgery. Additional histological examination took place at two hours (N = 8) and at two (N = 6), six (N = 6), 12 (N = 6), 16 (N = 6) and 29 (N = 6) weeks after surgery. Immediately after surgery (N = 40) and at two hours (N = 38) venous anastomoses were found to be patent in Doppler sonography. Anastomotic rupture caused death in two animals within one hour after surgery. Thrombotic occlusion was found in one animal at six weeks after surgery. In the remaining animals (N = 37) only minimal stenosis which decreased to almost normal levels was sonographically found. The average time needed for anastomosis using BAT was less than two minutes. BAT allows fast venous end-to-end anastomosis in a chicken throat vascular model.

Anastomosis, Surgical↗
PubMed2006

Correlated evolution between hearing sensitivity and social calls in bats.

Echolocating bats are auditory specialists, with exquisite hearing that spans several octaves. In the ultrasonic range, bat audiograms typically show highest sensitivity in the spectral region of their species-specific echolocation calls. Well-developed hearing in the audible range has been commonly attributed to a need to detect sounds produced by prey. However, bat pups often emit isolation calls with low-frequency components that facilitate mother-young reunions. In this study, we examine whether low-frequency hearing in bats exhibits correlated evolution with (i) body size; (ii) high-frequency hearing sensitivity or (iii) pup isolation call frequency. Using published audiograms, we found that low-frequency hearing sensitivity is not dependent on body size but is related to high-frequency hearing. After controlling for high-frequency hearing, we found that low-frequency hearing exhibits correlated evolution with isolation call frequency. We infer that detection and discrimination of isolation calls have favoured enhanced low-frequency hearing because accurate parental investment is critical: bats have low reproductive rates, non-volant altricial young and must often identify their pups within large crèches.

Animals↗