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PubMed2025

Broad geographical circulation of a novel vesiculovirus in bats in the Mediterranean region.

Bats are the natural reservoirs for a variety of emerging and re-emerging viruses. Among them, rabies virus (genus Lyssavirus, family Rhabdoviridae) is one of the first and most emblematic described in these animals. Since its first description, several new bat lyssaviruses have been regularly identified. In addition to lyssaviruses, other bat rhabdoviruses have also been discovered, including members of the genera Vesiculovirus, Ledantevirus and, more recently, Alphanemrhavirus and Tupavirus. However, the family Rhabdoviridae is one of the most abundant and diverse viral families, with 434 officially recognized species, divided into 5 subfamilies and 56 different genera. The number of rhabdoviruses associated with bats is therefore probably higher than that currently available. In this study, we first developed and validated a combined nested RT-qPCR technique (pan-rhabdo RT-nqPCR) dedicated to the broad detection of animal rhabdoviruses. After validation, this technique was used for a large retrospective screening of archival bat samples (n = 1962), including blood (n = 816), brain (n = 723) and oral swab (n = 423). These samples were collected from various bat species over a 12-year period (2007-2019) in 9 different countries in Europe and Africa. A total of 23 samples (1.2%) from bat species Miniopterus schreibersii, Rhinolophus euryale and Rhinolophus ferrumequinum tested positive for rhabdovirus infection, including 17 (2.1%) blood and 6 (1.4%) oral swab samples, all collected from bats originating from the Mediterranean region. Complete virus genome sequences were obtained by next-generation sequencing for most of the positive samples. Molecular and phylogenetic analysis of these sequences demonstrated that the virus isolates, named Mediterranean bat virus (MBV), were closely related and represented a new species, Mediterranean vesiculovirus, within the genus Vesiculovirus. MBV was more specifically related to other bat vesiculoviruses previously described from China and North America, together clustering into a distinct group of bat viruses within this genus. Interestingly, our results suggest that MBV is widespread, at least in the western part of the Mediterranean region, where it circulates in the blood of several bat species. These results expand the host range and viral diversity of bat vesiculoviruses, and pave the way for further studies to determine the transmission route and dissemination dynamics of these viruses in bat colonies, as well as to assess their potential threat to public health.

Animals↗
PubMed1989

Bat rabies in Illinois: 1965 to 1986.

From 1968 to 1986, Illinois (USA) citizens and agencies submitted 4,272 bats to the Illinois Department of Public Health for rabies testing. Of this number, 6% tested positive, a rate comparable to similar studies from other parts of North America. Due to sampling biases, the true infection rate among bats in Illinois is probably lower than 6%. Additional analysis relied on a subsample (n = 2,433) of the specimens collected from 1965 to 1986. Prevalences were significantly different among years, but no linear trends were found over the study period. Evidence for a local outbreak of bat rabies was found. Prevalences for the species with sample sizes adequate for statistical analysis were, from high to low: hoary bat (Lasiurus cinereus), 11%; red bat (L. borealis), 5%; silver-haired bat (Lasionycteris noctivagans), 4%; little brown bat (Myotis lucifugus), 4%; big brown bat (Eptesicus fuscus), 3%; Keen's bat (Myotis keenii), 2%; and evening bat (Nycticeius humeralis), 2%. The higher prevalences found among the non-colonial species (hoary, red and silver-haired bats) were consistent with similar studies. Considerable annual variation in prevalences was found within species, and the prevalence rankings of the species varied over the study period. Prevalences were significantly higher in females (6%) than in males (4%) when species were pooled, but no significant differences between sexes were found within species. In contrast to the other species analyzed, all of which had sex ratios favoring females, the big brown bat sample had a large majority of males. Prevalences were significantly higher in adults (6%) than in juveniles (3%) when species were pooled. Within individual species, significant differences between age groups were found only for hoary and red bats; in two species, juveniles had higher prevalences. Above average prevalences were observed in May and August to November. Southern Illinois had the highest prevalences; prevalences were intermediate in the north and lowest in the central region. Overall, the patterns of rabies prevalence among bats submitted by the public in Illinois from 1965 to 1986 were similar to those reported from other parts of North America.

Age Factors↗
PubMed2004

Rabies in a captive colony of big brown bats (Eptesicus fuscus).

Our research has focused on the ecology of commensal populations of big brown bats (Eptesicus fuscus) in Fort Collins, Colorado (USA), in relation to rabies virus (RV) transmission. We captured 35 big brown bats (Eptesicus fuscus) in late summer 2001 and held them captive for 4.8 mo. The bats were initially placed in an indoor cage for 1 mo then segregated into groups of two to six per cage. Two of the bats succumbed to rabies virus (RV) within the first month of capture. Despite group housing, all of the remaining bats were healthy over the course of the investigation; none developed rabies, although one of the rabid bats was observed to bite her cage mates. Reverse transcription-polymerase chain reaction (RT-PCR) and Taqman real-time PCR analysis of the RNA derived from the brain tissue, salivary glands, and oral swab samples confirmed RV infection in the dead bats. Rabies virus was also isolated from the brain tissue upon passage in mouse neuroblastoma cells. Nucleotide sequence analysis of the RV nucleoprotein (N) gene showed 100% identity with the N gene sequence of a 1985 E. fuscus isolate from El Paso County, Colorado. Bat sera obtained six times throughout the study were assayed for RV neutralizing antibodies using the rapid fluorescent focus inhibition test. The RV neutralizing activity in the serum was associated with the IgG component, which was purified by binding to protein G Sepharose. Five bats were RV seropositive prior to their capture and maintained titers throughout captivity. Two adult bats seroconverted during captivity. Two volant juvenile bats had detectable RV antibody titers at the first serum collection but were negative thereafter. Four seronegative bats responded to a RV vaccine administration with high titers of RV antibodies. A serologic survey of big brown bats in the roost from which one of the captive rabid bats had originated showed a significant rise in seroprevalence during 2002.

Animals↗
PubMed1996

Bifunctional NHS-BAT ester for antibody conjugation and stable technetium-99m labeling: conjugation chemistry, immunoreactivity and kit formulation.

UNLABELLED: Conjugation chemistry and kit formulated binding of the NHS ester of 6-(4'-(4"-carboxyphenoxy)butyl)-2, 10-dimercapto-2,10-dimethyl-4,8-diazaundecane (NHS-BAT ester) to monoclonal antibodies (MAbs) was investigated. The functionalities of the resulting BAT conjugated and 99mTc-labeled MAbs BW 431/26, MAb 425 and bispecific MDX210 (fragment construct) were tested by immunoreactivity and immunoscintigraphy. METHODS: The kinetics and chemistry of the conjugation reaction were monitored by high-performance liquid chromatography, size-exclusion chromatography and positive fast-atom-bombardment mass spectra (FAB-MS). The 99mTc BAT-MAbs were tested with various immunoreactivity assays. The biodistribution of 99mTc-BAT-BW 431/26 in rats was compared with directly labeled BW 431/26. RESULTS: At pH 8.5 and 25 degrees C, the reactivity of the NHS-BAT ester was high with 90% completion after 30 min. The conjugation yield of 19 microM MAb and 228 microM NHS-BAT ester amounted to 30%. Higher NHS-BAT ester concentrations afforded higher BAT-to-MAb ratios. According to FAB-MS, the conjugation competing hydrolysis surprisingly occurred at the NHS ring. Almost quantitative 99mTc labeling was achieved after 5 min at 25 degrees C. Immunoreactivity of the 99mTc-BAT antibodies showed > 90% recovery and proved to be insensitive to BAT-to-MAb ratios of up to 10. The 99mTc-BAT-BW 431/26 showed similar organ distribution but revealed less urinary excretion compared with the directly labeled BW 431/26. Immunoscintigraphy with 99mTc-labeled and BAT-BW 431/26 and BAT-MAb 425 showed the respective biological function in vivo. CONCLUSION: According to straightforward conjugation chemistry, the ease of 99mTc labeling and the application of a simple ultrafiltration technique, the NHS-BAT ester represents a nondestructive, universally applicable biofunctional ligand to introduce stable 99mTc protein binding sites. Kit formulated conjugation/labeling can be performed with little time requirements and laboratory experience.

Animals↗
PubMed2003

99mTcO(BAT-NI), a novel nitroimidazole tracer: in vivo uptake studies in ischaemic myocardium.

Myocardial perfusion single-photon emission tomography (SPET) performed with cationic technetium-99m complexes indicates ischaemic areas as cold lesions. By contrast, nitroimidazole derivatives labelled with fluorine-18 or (99m)Tc have recently shown promising results for hot spot imaging of ischaemic myocardium. This study evaluates (99m)TcO(BAT-NI), a new (99m)Tc complex comprising the nitroimidazole ligand, 2,10-dimercapto-2,10-dimethyl-4,8-diaza-6-[4-(2-nitroimidazolyl)butyl]undecane, in a low-flow in vivo model of myocardial ischaemia in thoracotomised rats. To elucidate the influence of the 2-nitroimidazole group on ischaemia-induced uptake, comparisons with ligand derivatives were performed where (a) the 2-nitro group was deleted [(99m)TcO(BAT-I)], (b) the 2-nitroimidazole functionality was replaced by a Br atom [(99m)TcO(BAT-Br)] and (c) the (99m)TcO(BAT) moiety was replaced by an iodine-125 iodophenoxybutyl ligand ((125)IP-NI). The radiolabelled compounds were i.v. injected 15 min after reducing resting myocardial blood flow by 50-60% and the uptake of radioactivity was assessed 90 min post injection. Autoradiography of left ventricular short-axis slices showed median uptake ratios of ischaemic/non-ischaemic myocardium (I/N) of 3.4, 4.5 and 3.4 for (99m)TcO(BAT-NI), (99m)TcO(BAT-I) and (99m)TcO(BAT-Br), respectively. In contrast, (125)IP-NI was not preferentially taken up by ischaemic myocardium. Accumulation of (99m)TcO(BAT-NI) in ischaemic heart regions was comparable to that in the liver. Biodistribution studies showed a median uptake of 0.65% ID/g of (99m)TcO(BAT-NI) in ischaemic tissue and an I/N of 3.3. On planar images of the thorax and upper abdomen the ischaemic hearts were visualised faintly; the median heart to lung count ratio for (99m)TcO(BAT-NI) was 1.7, and the median heart to liver count ratio was 1.0. We conclude that uptake of (99m)TcO(BAT-NI) in ischaemic myocardium does not depend on the nitroimidazole moiety but is intrinsic to the BAT complex. Clinical use of the (99m)TcO(BAT)-labelled tracers seems unlikely owing to their low uptake and their low ischaemic tissue contrast on planar images in vivo.

Animals↗
PubMed2000

Torpor, thermal biology, and energetics in Australian long-eared bats (Nyctophilus).

Previous studies have suggested that Australian long-eared bats (Nyctophilus) differ from northern-hemisphere bats with respect to their thermal physiology and patterns of torpor. To determine whether this is a general trait of Australian bats, we characterised the temporal organisation of torpor and quantified metabolic rates and body temperatures of normothermic and torpid Australian bats (Nyctophilus geoffroyi, 7 g and N. gouldi, 10 g) over a range of air temperatures and in different seasons. The basal metabolic rate of normothermic bats was 1.36 +/- 0.17 ml g(-1) h(-1) (N. geoffroyi) and 1.22 +/- 0.13 ml g(-1) h(-1) (N. gouldi), about 65% of that predicted by allometric equations, and the corresponding body temperature was about 36 degrees C. Below an air temperature of about 25 degrees C bats usually remained normothermic for only brief periods and typically entered torpor. Arousal from torpor usually occurred shortly after the beginning of the dark phase and torpor re-entry occurred almost always during the dark phase after normothermic periods of only 111 +/- 48 min (N. geoffroyi) and 115 +/- 66 min (N. gouldi). At air temperatures below 10 degrees C, bats remained torpid for more than 1 day. Bats that were measured overnight had steady-state torpor metabolic rates representing only 2.7% (N. geoffroyi) and 4.2% (N. gouldi) of the basal metabolic rate, and their body temperatures fell to minima of 1.4 and 2.3 degrees C, respectively. In contrast, bats measured entirely during the day, as in previous studies, had torpor metabolic rates that were up to ten times higher than those measured overnight. The steady-state torpor metabolic rate of thermoconforming torpid bats showed an exponential relationship with body temperature (r2 = 0.94), suggesting that temperature effects are important for reduction of metabolic rate below basal levels. However, the 75% reduction of metabolic rate between basal metabolic rate and torpor metabolic rate at a body temperature of 29.3 degrees C suggests that metabolic inhibition also plays an important role. Torpor metabolic rate showed little or no seasonal change. Our study suggests that Australian Nyctophilus bats have a low basal metabolic rate and that their patterns of torpor are similar to those measured in bats from the northern hemisphere. The low basal metabolic rate and the high proclivity of these bats for using torpor suggest that they are constrained by limited energy availability and that heterothermy plays a key role in their natural biology.

Adaptation, Physiological↗
PubMed1994

Brain activity patterns in flying, echolocating bats (Pteronotus parnellii): assessment by high resolution autoradiographic imaging with [3H]2-deoxyglucose.

Brain activity patterns during echolocation and flight were assessed in mustached bats (Pteronotus parnellii parnellii). Bats were injected intraperitoneally with [3H]2-deoxyglucose and restrained in a foam holder or allowed to fly for 20 min. Under resting conditions, low levels of [3H]2-deoxyglucose uptake were observed throughout the forebrain but relatively high uptake was found in brainstem auditory and vestibular centers. In flying, echolocating bats, marked increases in regional [3H]2-deoxyglucose uptake were apparent. All structures of the classical ascending auditory pathway were intensely labeled in autoradiograms. Other brain regions that exhibited high [3H]2-deoxyglucose uptake in flying bats included the cingulate cortex, stratum lacunosum-moleculare of the hippocampus, thalamus, caudate-putamen, superior colliculus, pontine reticular formation, nucleus ambiguus, parts of the midbrain central gray, and cerebellum. In the cerebellum, the most prominent increase in [3H]2-deoxyglucose uptake was found in discrete patches of the granule cell layer. The results provide the first overview of brain activity patterns during echolocation and flight in bats. In addition, uptake of [14C]fluorodeoxyglucose was used to compare brain activity patterns in flying bats to bats that were imaging their environment via biosonar while hanging in a wire cage. The echolocating-not-flying bats emitted 6931 +/- 1226 pulses in 20 min compared to 8972 +/- 1273 pulses in 20 min for flying bats. The uptake of the metabolic marker was significantly more in the flying bats compared to the emitting-not-flying bats in the medial geniculate, superior colliculus, auditory cortex, cingulate cortex and thalamus. In the nucleus ambiguus, cochlear nucleus, and inferior colliculus, uptake was similar for the flying and emitting-not-flying bats. These results suggest that the high metabolic activity observed in forebrain auditory regions of flying bats is related in part to neural processes that involve sensory motor integration during flight and not simply the perception of acoustic information.

Animals↗
PubMed2004

Effect of grip strength and grip strengthening exercises on instantaneous bat velocity of collegiate baseball players.

Bat velocity is considered to be an important factor for successful hitting. The relationship between grip strength and bat velocity has not been conclusively established. The purposes of this study were to determine the relationship of grip strength to bat velocity and to ascertain whether the performance of resistance training exercises designed to specifically target the forearms and grip would significantly alter bat velocity. The subjects for this study were 23 male members (mean +/- SD, age = 19.7 +/- 1.3 years, height = 182.5 +/- 5.9 cm, weight = 85.4 +/- 15.5 kg, experience = 14.4 +/- 1.7 years) of a varsity baseball team at a National Collegiate Athletic Association Division II school. The Jamar hand dynamometer was used to test grip strength, and the SETPRO Rookie was used to measure instantaneous bat velocity at the point of contact with the ball. Subjects were randomly divided into an experimental group and a control group. For 6 weeks, both groups participated in their usual baseball practice sessions, but the experimental group also performed extra forearm and grip strengthening exercises, whereas the control group did not. Pretest and posttest correlations between grip strength and bat velocity revealed no significant relationship between grip strength and bat velocity (pretest r = 0.054, p = 0.807; posttest r = 0.315, p = 0.145). A dependent t-test performed on all subjects revealed that a significant (p = 0.001) increase in bat velocity did occur over the course of the study. A covariate analysis, employing pretest bat velocity as the covariate, revealed no significant difference (p = 0.795) in posttest bat velocity scores between the experimental and control groups. Thus, increases in bat velocity occurred, but the differences were similar for both the experimental and control groups. The findings of this study suggest that grip strength and bat velocity are not significantly related, and that the allocation of time and energy for added training of the forearms in order to improve grip strength for the purpose of increasing bat velocity may not be warranted.

Adult↗
PubMed1986

Rabies in insectivorous bats of western Canada, 1979 to 1983.

A total of 1,745, 362, and 536 bats collected in Alberta, British Columbia, and Saskatchewan, respectively, was tested for rabies virus between 1979 and 1983. Only one (0.1%) of 769 bats collected at random from buildings was infected with rabies virus in contrast to 95 (5%) of 1,874 symptomatic, rabies-suspect bats submitted for testing. The pattern of infection in the rabies-suspect bats was similar in Alberta and Saskatchewan, but differed in British Columbia. Rabies was diagnosed in four species of bats in each of Alberta and Saskatchewan, but in seven species in British Columbia. Annual prevalence in rabies-suspect bats was similar in colonial species within each province. Rabies was found rarely in suspect little brown bats (Myotis lucifugus) (less than 1%). In suspect big brown bats (Eptesicus fuscus), the prevalence was low in Saskatchewan (3%), moderate in Alberta (10%), and high in British Columbia (25%). Big brown bats accounted for over 55% of the rabid bats detected in each province. Annual prevalence reported in silver-haired bats (Lasionycteris noctivagans) and hoary bats (Lasiurus cinereus) was variable in all three provinces. Rabies is enzootic in northern insectivorous bats.

Animals↗
PubMed2006

Bat rabies in Europe: a review.

Bats are legally protected in most European countries under some international treaties and national nature conservation legislations that prohibit deliberate capture and killing of bats except under permit from the competent authorities. However, bat rabies research is necessary to gain insight into whether bat rabies is a real problem for public health and whether bat conservation efforts are in conflict with public health interests. It is also important to know the incidence of rabies in different bat species. Thus far, passive surveillance of bat rabies seems to be a sufficient mean of obtaining information about the occurrence of bat rabies that is not in conflict with bat conservation. Knowledge about the occurrence of bat rabies, the prevalence of rabies in particular species of bats, and the possible risk for public and animal health is also important for improving public awareness for bat conservation in conjunction with public health. There should, therefore, be good cooperation between bat conservationists and rabies research bodies.

Animal Technicians↗
PubMed2000

Characterisation of a recently isolated lyssavirus in frugivorous zoo bats.

In July 1997 a lyssavirus was isolated in Denmark from a colony of Egyptian flying foxes (Rousettus aegyptiacus) originating from a Dutch zoo. Sequencing of a 400 nucleotides coding region of the nucleoprotein and of a major part of the G-protein ectodomain encoding region of the newly isolated virus, revealed a very high similarity with European Bat Lyssavirus subtype 1a (EBL-1a). For characterisation of the recently isolated lyssavirus in frugivorous zoo bats, 16 frugivorous bats (Rousettus aegyptiacus) of the same colony and 80 mice were experimentally infected with the Rousettus isolate or with a well defined EBL-1a strain isolated from a Dutch insectivorous bat (Eptesicus serotinus). Inoculation viruses were titrated in mice to determine LD50's of both isolates. Clinical signs of inoculated bats were recorded during 6 weeks. After showing neurological signs or at the end of the experimental infection all animals were euthanized. During the experimental infection sera and various tissues of inoculated bats were collected. Immunoassays, mouse inoculation tests (MIT) and polymerase chain reaction (PCR) were employed for detection of lyssavirus specific antibodies, antigen or RNA. Five bats inoculated with the Rousettus isolate and 2 bats inoculated with the Eptesicus isolate showed neurological signs. The remaining 9 bats survived and cleared the virus; at least under the detection limit of the used assays. Despite a much higher pathogenicity of the Rousettus isolate observed in mice, LD25's in bats were quite the same for the 2 isolates. The pathogenicity of both isolates suggested that like many other mammals, Rousettus aegyptiacus bats could be victims of lyssavirus infection besides reservoir hosts of infectious EBL1a. There was no significant difference in detecting the different lyssavirus isolates in Rousettus aegyptiacus bats. An employed immunoperoxidase staining (IP) method was very useful for sensitive detection and localization of lyssavirus antigen in histologic preparates.

Animals↗
PubMed2004

DDT and metabolites residues in the southern bent-wing bat (Miniopterus schreibersii bassanii) of south-eastern Australia.

The southern bent-wing bat (Miniopterus schreibersii bassanii) is an insectivorous, obligate cave dwelling species found in south-eastern South Australia and western Victoria, Australia. In recent times, the finger of blame for an apparent population decline at Bat Cave, Naracoorte (one of only two known maternity roosts for this species, the other being Starlight Cave, Warrnambool) has been pointed at pesticide use in the region, following the finding of organochlorine and organophosphate insecticide residues in bat guano. This study sampled juvenile southern bent-wing bats from Bat Cave and Starlight Cave, and determined DDT, DDD and DDE concentrations in liver, pectoral muscle, brain and back-depot fat tissues. DDT was detected in only three tissue samples (highest concentration, 126 microg kg(-1) (wet weight) in back-depot fat), DDD was detected only in brain tissue (highest concentration, 115 microg kg(-1) (wet weight)), but DDE was detected in most tissues (highest concentration, 24,200 microg kg(-1) (wet weight) in back-depot fat). A minimum DDE body burden was estimated for each bat, and then for each sex at each site, from the data from all tissues sampled. The DDE body burdens estimated were highest in male bats from Starlight Cave (114 microg kg(-1)), then females from Starlight Cave (54.5 microg kg(-1)), and males from Bat Cave (53.2 microg kg(-1)). Female bats at Bat Cave contained the lowest estimated body burden (24.2 microg kg(-1)). Comparisons of DDE concentrations between the sexes showed that contamination was not statistically different within each maternity site. The different chemical concentrations observed in the Bat Cave and Starlight Cave bats is suggestive of different feeding locations, and perhaps an emerging population split, further threatening a species already at risk as a result of landscape scale changes to land use across their range.

Adipose Tissue↗
PubMed1994

The epidemiology of bat rabies in New York State, 1988-92.

In 1993 New York and Texas each reported a human rabies case traced to a rare variant of rabies virus found in an uncommon species of bat. This study examined the epidemiology of bat rabies in New York State. Demographic, species, and animal-contact information for bats submitted for rabies testing from 1988-92 was analysed. The prevalence of rabies in 6810 bats was 4.6%. Nearly 90% of the 308 rabid bats identified to species were the common big brown bat (Eptesicus fuscus), which comprised 62% of all submissions. Only 25 submissions were silver-haired bats (Lasionycterus noctivagans), the species associated with the two 1993 human cases of rabies, and only two of these bats were positive. Rabies was most prevalent in female bats, in bats submitted because of human [corrected] contact, and in animals tested during September and October. These results highlight the unusual circumstances surrounding the recent human rabies cases in the United States. A species of bat rarely encountered by humans, and contributing little to the total rabies cases in bats, has been implicated in the majority of the indigenously acquired human rabies cases in the United States. The factors contributing to the transmission of this rare rabies variant remain unclear.

Animals↗
PubMed1990

Biosonar behavior of mustached bats swung on a pendulum prior to cortical ablation.

1. The biosonar signal (pulse) of the mustached bat, Pteronotus parnellii parnellii, has four harmonics (H1-4), each consisting of a long constant-frequency component (CF1-4) followed by a short frequency-modulated component (FM1-4). As the bat approaches a target, it systematically modifies its pulses to optimize the extraction of information from the echoes. These behavioral responses include 1) Doppler-shift (DS) compensation in which the bat adjusts the frequency of its pulses to correct for the DS in the echoes. This maintains the echo CF2 at a frequency to which the bat's cochlea is very sharply tuned, slightly above the CF2 frequency of the bat's pulses when it is at rest (Frest, approximately 61 kHz); 2) echo intensity compensation, in which the bat lowers its pulse intensity as it approaches a large target, thus maintaining the echo intensity within a suitable range for auditory processing; and 3) and 4) duration and rate adjustments, in which the bat first increases its pulse duration to facilitate target identification, then shortens its pulse duration while increasing its pulse rate to facilitate target analysis. 2. We examined these responses, especially DS compensation, by swinging bats on a pendulum toward a large target over a distance of 3.6 m. Eight bats were given 15-30 swings per day for 6-25 days. 1) On 97% of all swings the bats showed strong DS compensation as the pendulum approached the target. They did not show DS compensation on the backswing. 2) On 40-50% of all swings, the bats clearly displayed the other responses. The bats typically increased their pulse intensity a small amount early in the pendulum swing, then decreased pulse intensity by as much as 18 dB as the target was more closely approached. They increased their pulse intensity during the backswing. 3) Pulse duration increased from approximately 20 to 23 ms early in the forward swing, decreased to approximately 18 ms as the target was more closely approached, and then increased to 20 ms by the end of the backswing. 4) The instantaneous repetition rate increased from approximately 17 pulses/s at the start of the forward swing to approximately 28 pulses/s near the target, then decreased to approximately 10 pulses/s by the end of the backswing. Pulses usually occurred in trains of 1-2 pulses, with longer trains occasionally occurring near the target. 3. The maximum DS on the pendulum was 1.34 kHz, and the maximum DS compensation was 146 +/- 98 (SD) Hz less than this value.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed2025

Metagenomic analysis of viral diversity in Portuguese bats.

Bats are highly diverse mammals and known reservoirs of numerous zoonotic viruses. Their role in the ecology of emerging infectious diseases continues to be of significant interest. This study aimed to evaluate the occurrence of coronaviruses (CoVs) in Portuguese bats and predict the affinity of their spike proteins with the aminopeptidase N (APN) receptor of several host species. The study also explored the viral diversity in bat samples using metagenomic sequencing. Ten bats (five Myotis myotis and five Miniopterus schreibersii) were captured at an underground roost in 2022 (Central Portugal), and fecal samples, oral, and anal swabs were collected (n = 27). A Pan-CoV nested RT-PCR was used for initial screening, followed by viral metagenomic sequencing of all fecal samples and one CoV-positive buccal swab. In silico protein docking studies were performed between a Portuguese bat CoV spike protein and APNs of bats, pigs, and humans. Pan-CoV nested RT-PCR identified three positive samples: two fecal samples and one buccal sample. Metagenomic sequencing allowed us to determine two near complete CoV genomes. Protein docking predicted strong binding of this spike protein to bat, porcine, and human APN receptors. Metagenomics also identified picornaviruses, adenovirus, and dependoparvovirus in fecal samples. This study reports the first near complete genome sequences of two members of the Alphacoronavirus genus from a Portuguese bat The identification of other viral families highlights the diverse virome of these cave-dwelling bat species. Protein docking studies suggest a potential for cross-species transmission of this bat CoV between bats, porcines and humans, though further research is needed to confirm these interactions.

Animals↗
PubMed2026

Integrated transcriptomic analysis of mRNA and miRNA in Brown adipose tissue of the greater horseshoe bats during hibernation.

Hibernation enables animals survive harsh environments by conserving energy through reduced metabolism and body temperature. Brown adipose tissue (BAT) plays a critical role in non-shivering thermogenesis, crucial for warming up during arousal phase. The greater horseshoe bats (Rhinolophus nippon) are typical hibernators and non-shivering thermogenesis in BAT tissue may persist throughout the arousal process in bats. This study examines gene expression and regulatory changes in BAT of these bats across active, hibernation, and arousal phases using transcriptome and miRNA sequencing. A total of 2721 differentially expressed mRNAs and 268 differentially expressed miRNAs were identified. The results reveal that the BAT transcriptome undergoes state-dependent remodeling throughout the hibernation process. The most pronounced divergence occurs between the active phase and torpor, involving cell cycle arrest, immunosuppression, thermogenic signal desensitization, and upregulation of lipid metabolism and autophagy pathways, reflecting the coordinated adaptation of energy conservation and thermogenic reserve. In contrast, transcriptional alterations between torpor and arousal are extremely limited, indicating that torpid BAT is already pre-primed for thermogenesis and requires only modest transcriptional adjustments to activate heat production. Notably, although body temperature recovers to active-phase levels during arousal, the molecular signature of BAT remains highly similar to that of the torpid state. Furthermore, the core thermogenic gene UCP1 showed no significant expression differences across the three groups. In conclusion, this study systematically delineates the miRNA-mRNA regulatory landscape of bat BAT across the hibernation process, and deepens our understanding of the thermoregulatory mechanisms underlying mammalian hibernation.

BAT↗
PubMed1997

Enhancement of 67Cu-2IT-BAT-LYM-1 therapy in mice with human Burkitt's lymphoma (Raji) using interleukin-2.

BACKGROUND: Lymphomas have been shown to be responsive to 131I immunoconjugates in studies conducted in mice and patients. We have observed that copper 67 (67Cu)-labeled Lym-1 remains in lymphomatous tissue longer than 131I-Lym-1 and, consequently, results in higher absorbed radiation doses to tumors. In addition, recombinant interleukin-2 (rIL-2) has been reported to increase tumor uptake of radiolabeled antibody. Therefore, we examined the efficacy of 67Cu-labeled Lym-1 and the ability of rIL-2 to enhance this efficacy in athymic mice implanted with Raji xenografts. METHODS: 6[p-(bromoacetamido) benzyl]-1,4,8,11-tetraazacyclotetradecane-N,N', N'',N'''-tetraacetic acid (BAT) was conjugated to Lym-1 via 2-iminothiolane (2IT) to prepare 2IT-BAT-Lym-1, which was labeled with 67Cu. Mice with Raji xenografts were treated with 335-500 microCi (12.4-18.0 MBq) of 67Cu-2IT-BAT-Lym-1 with or without 48,000-144,000 IU of rIL-2 once or were treated b.i.d. for 5 days beginning simultaneously with 67Cu-2IT-BAT-Lym-1. Mouse weight, blood counts, and mortality were monitored to assess toxicity, and tumor size was measured to assess efficacy. In addition, groups of mice were sacrificed to assess the biodistribution of 67Cu-2IT-BAT-Lym-1 with and without rIL-2. RESULTS: In mice treated with 335 microCi of 67Cu-2IT-BAT-Lym-1 alone, 28% of tumors were cured. When 48,000 IU of rIL-2 were added, 50% were cured. The overall response-rate was 50% for both regimens. In mice treated with 400 microCi of 67Cu-2IT-BAT-Lym-1 alone, 42% responded, all of which were cured. When 48,000 IU of rIL-2 were added, 77% of tumors responded, and 38% were cured. Larger or multiple doses of rIL-2 did not result in additional therapeutic enhancement. The tumor uptake and radiation dose after 67Cu-2IT-BAT-Lym-1 were about two times greater when a single dose of rIL-2 was added: This may be the basis for enhanced therapeutic efficacy. Mortality was not altered for 335 microCi or 400 microCi doses of 67Cu-2IT-BAT-Lym-1 by rIL-2 nor were other toxicity parameters. Mortality was increased at 500 microCi by the addition of rIL-2. CONCLUSIONS: 67Cu-2IT-BAT-Lym-1 provided a therapeutic and frequently curative dose of radiation to tumored mice at tolerated doses. The therapeutic effectiveness of 67Cu-2IT-BAT-Lym-1 may have been enhanced by rIL-2.

Animals↗
PubMed2003

Evaluation of an algorithm for calculation of serum "bioavailable" testosterone (BAT).

OBJECTIVES: To evaluate a recently published algorithm for calculation of serum "Bioavailable" Testosterone (BAT) using serum Total Testosterone (TT), Sex Steroid Binding Globulin (SSBG) [also commonly known as Sex Hormone Binding Globulin (SHBG)] and albumin concentrations as parameters, in comparison with a locally available "salting-out" BAT method. If satisfactory, this calculation could serve as a substitute for the BAT assay, which would amount to a major cost saving and faster turnaround time. DESIGN AND METHODS: During a 6-month period, 426 serum samples referred for BAT analysis to the Hospitals In-Common Laboratory of Toronto were also analyzed in-house for TT, SSBG and albumin for computation of comparison calculated BAT results. RESULTS: A good statistical correlation was obtained, but only after unexpectedly drastic empirical modification of the association constant values: r=0.95, Calculated %BAT=0.971 x Measured %BAT + 0.008. The endocrinologist/andrologist of our team (JB), who was the responsible physician for all patients included in this study, reviewed the tabulated and charted calculated BAT results and verified that they were clinically equivalent. CONCLUSIONS: Although it is feasible to calculate BAT, the algorithm is not directly portable. Before adopting such a calculation each laboratory should compare it with the locally available BAT method and consider adjusting the calculation to optimize the correlation. Future reassessment may be necessary whenever the SSBG, TT or BAT assay is changed.

Algorithms↗