Experimental Infection of Mexican Free-Tailed Bats (Tadarida brasiliensis) with SARS-CoV-2.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus is thought to have originated in wild bats from Asia, and as the resulting pandemic continues into its third year, concerns have been raised that the virus will expand its host range and infect North American wildlife species, including bats. Mexican free-tailed bats (Tadarida brasiliensis) live in large colonies in the southern United States, often in urban areas and, as such, could be exposed to the virus from infected humans. We experimentally challenged wild T. brasiliensis with SARS-CoV-2 to determine the susceptibility, reservoir potential, and population impacts of infection in this species. Of 10 bats oronasally inoculated with SARS-CoV-2, 5 became infected and orally excreted moderate amounts of virus for up to 18 days postinoculation. These five subjects all seroconverted and cleared the virus before the end of the study with no obvious clinical signs of disease. We additionally found no evidence of viral transmission to uninoculated subjects. These results indicate that while T. brasiliensis are susceptible to SARS-CoV-2 infection, infection of wild populations of T. brasiliensis would not likely cause mortality. However, the transmission of SARS-CoV-2 from T. brasiliensis to or from humans, or to other animal species, is a possibility requiring further investigation to better define. IMPORTANCE As the COVID-19 pandemic has continued for 3+ years, there has been increasing concern that the SARS-CoV-2 virus will enter wildlife populations and potentially create new reservoirs where the virus could adapt to a new host and create variants. This is particularly possible with species that reside in man-made structures, in proximity to infected human populations. Mexican free-tailed bats (Tadarida brasiliensis) live in large colonies, often in urban settings and, thus, can be exposed by infected humans and potentially transmit the virus to new hosts. We experimentally challenged T. brasiliensis with SARS-CoV-2 and revealed that they are susceptible to the virus and excrete moderate amounts for up to 18 days postinoculation. This is important information for wildlife biologists, wildlife rehabilitation workers, and the general public that may contact these animals.

Experimental infection of Mexican free-tailed bats ( Tadarida brasiliensis) with SARS-CoV-2.

The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus originated in wild bats from Asia, and as the resulting pandemic continues into its third year, concerns have been raised that the virus will expand its host range and infect North American wildlife species, including bats. Mexican free-tailed bats ( Tadarida brasiliensis : TABR) live in large colonies in the southern United States, often in urban areas, and as such, could be exposed to the virus from infected humans. We experimentally challenged wild TABR with SARS-CoV-2 to determine the susceptibility, reservoir potential, and population impacts of infection in this species. Of nine bats oronasally inoculated with SARS-CoV-2, five became infected and orally excreted moderate amounts of virus for up to 18 days post inoculation. These five subjects all seroconverted and cleared the virus before the end of the study with no obvious clinical signs of disease. We additionally found no evidence of viral transmission to uninoculated subjects. These results indicate that while TABR are susceptible to SARS-CoV-2 infection, infection of wild populations of TABR would not likely cause mortality. However, the transmission of SARS-CoV-2 from TABR to or from humans, or to other animal species, is a distinct possibility requiring further investigation to better define.

Descriptive assessment of adverse events associated with midazolam-etomidate versus saline-etomidate in healthy hydromorphone premedicated dogs.

OBJECTIVES: To determine the frequency, severity and duration of adverse events including myoclonus, pain on injection, hypersalivation, regurgitation and apnoea after administration of midazolam or saline followed by etomidate in hydromorphone premedicated dogs. MATERIALS AND METHODS: Dogs undergoing elective dental prophylaxis or soft tissue surgeries were enrolled in this randomised trial. Dogs were premedicated with hydromorphone 0.1 mg/kg IV. Sixty seconds later, midazolam 0.3 mg/kg or saline at an equivalent volume was administered IV. Sixty seconds after that, etomidate 1.5 mg/kg IV was administered over 60 seconds. Additional doses of 0.5 mg/kg etomidate were administered until endotracheal intubation was successful. Observers were blinded to the treatment. Frequency, duration and a severity score of 0 to 3 were recorded for myoclonus, pain on injection, hypersalivation and regurgitation. Duration of apnoea and frequency of any additional complications was recorded. RESULTS: Forty variable breed healthy dogs were enrolled in the study. Myoclonus, pain on injection, regurgitation, hypersalivation, gagging, tachypnoea and pigmenturia occurred, respectively, in 10%, 40%, 0%, 15%, 35%, 25% and 5% of dogs in the saline group and 0%, 65%, 0%, 10%, 45%, 15% and 5% of dogs in the midazolam group. Apnoea occurred for 115 seconds (range 0 to 660 seconds) and 160 seconds (range 0 to 600 seconds) in the saline and midazolam groups, respectively. Two dogs developed pigmenturia. The trial was stopped early due to the occurrence of pigmenturia. CLINICAL SIGNIFICANCE: Due to early stopping of the trial, the predefined sample size was not reached. Further investigation is needed to determine if midazolam reduced the incidence of adverse events or improved the induction quality when combined with hydromorphone and etomidate.

The effect of induction with propofol or ketamine and diazepam on quality of anaesthetic recovery in dogs.

OBJECTIVE: To evaluate the quality of recovery in dogs undergoing elective orthopaedic surgery induced with either propofol or a combination of ketamine and diazepam. MATERIALS AND METHODS: Sixty client-owned dogs undergoing single-limb elective orthopaedic procedures were enrolled. Dogs were randomly assigned to receive induction with propofol (4 mg/kg) (group P) or ketamine (5 mg/kg) with diazepam (0.25 mg/kg) (group KD) to which all scorers were blinded. The recovery monitoring period lasted for 1 hour following extubation. The recovery period was video-recorded for blinded scoring at a later time. Scoring for quality of recovery was carried out using three different systems (lower numbers=better quality): a simple descriptive scale (1 to 5), a visual analogue scale (0 to 10 cm) and a numeric rating scale (0 to 10). Videos were reviewed by three ACVAA board-certified anaesthesiologist raters. RESULTS: Five dogs were deemed to be ineligible. The mean (±SD) duration of anaesthesia was 260.4 ±57.84 minutes in group KD and 261.1 ±51.83 minutes in group P. There was no difference between groups for time to extubation, head lift or sternal recumbency. The number of dogs having a recovery that was scored overall as bad (mean simple descriptive scale > 4, mean visual analogue scale or numeric rating scale > 5) was not different between groups. Dogs in group KD had significantly lower scores than group P dogs (simple descriptive scale P=0.01, numeric rating scale P=0.03, visual analogue scale P=0.03). CLINICAL SIGNIFICANCE: Induction with ketamine and diazepam resulted in a smoother recovery from anaesthesia than induction with propofol.

Treatment time, ease of use and cost associated with use of Equashield™, PhaSeal® , or no closed system transfer device for administration of cancer chemotherapy to a dog model.

This prospective experimental simulation study evaluated the efficiency, ease of use (EOU) and cost of administering chemotherapy with two closed system transfer devices (CSTD, Equashield™ and PhaSeal® ) and no CSTD. Forty-six veterinary technicians (VT) working in oncology specialty practices were timed during chemotherapy administration simulated with water and a model canine limb 10 times with each system and with no CSTD. EOU and likelihood of recommending each system were rated by VT using visual analog scales. Costs were obtained from veterinary distributors. Administration was fastest with Equashield™ (P = 0.0003), but the difference was not enough to affect case flow. Equashield™ was easier to use than PhaSeal® or no CSTD (P = 0.002), however VT recommended both CSTD more strongly than no CSTD (P < 0.0001). Equashield™ cost less than PhaSeal® but was sold only in bulk quantities. CSTD did not decrease efficiency in administering chemotherapy and were readily accepted by VT.

Prospective evaluation of the safety of compounded bulk material L-asparaginase in dogs with lymphoma.

Use of compounded L-asparaginase became routine in veterinary oncology when manufacturing of Elspar® was discontinued in 2012. The objective of this study was to evaluate the safety of compounded L-asparaginase (CLASP, KRS Global Biotechnology, Boca Raton, FL, USA) in comparison with Elspar® (Lundbeck LLC, Deerfield, IL, USA). In addition, we documented the response to CLASP in combination with a corticosteroid in this population of dogs with lymphoma. Dogs were prospectively treated with 10 000 IU/m2 CLASP or Elspar® subcutaneously. Corticosteroids were administered concurrently. Adverse events (AE) were assessed according to the Veterinary Cooperative Oncology Group Common Terminology Criteria for Adverse Events v1.1 (VCOG-CTCAE). Response was recorded. Seventy-three dogs received 75 treatments (CLASP, n = 47; Elspar® , n = 28). No AE were attributed to CLASP. Grade I and II AE probably or possibly related to treatment were observed following two Elspar® treatments. The overall response rate to the combination of CLASP and a corticosteroid was 80% (24% CR and 56% PR). In combination with a steroid, the compounded L-asparaginase evaluated in this study is safe and demonstrates activity against canine lymphoma. In the face of the discontinuation of Elspar® , veterinarians should seek compounded LASP products that have been tested for activity, purity, and sterility.

The effect of midazolam on the recovery quality, recovery time and the minimum alveolar concentration for extubation in the isoflurane-anesthetized pig.

There are no reported studies evaluating the effect of midazolam on recovery quality, recovery time or minimum alveolar concentration (MAC) at which extubation occurs (MAC extubation). Our hypotheses were that midazolam administered prior to recovery would decrease MAC extubation, prolong recovery time but provide a smoother recovery. Sixteen Yorkshire pigs were anesthetized with isoflurane for approximately 5 h. The end-tidal isoflurane concentration was then stabilized at 1.4% for 20 min. Pigs were randomly assigned to receive midazolam or saline. The vaporizer was decreased by 10% every 10 min until extubation. Pigs were declared awake by a blinded observer and were assigned a recovery score by the same observer. Mean MAC extubation was not significantly different for pigs receiving saline prior to recovery compared with those pigs receiving midazolam. The overall mean MAC extubation for both groups was 0.6 ± 0.4 vol%. Time to extubation was not significantly longer with midazolam (124 ± 36 min) compared with the saline group (96 ± 61 min; P = 0.09). Recovery score was not significantly different between groups (midazolam, 0.86 ± 1.1; saline 0.5 ± 0.5; P = 0.26). In conclusion, midazolam did not affect MAC extubation. There was no advantage of administering midazolam in the recovery period when performing step-down titration of isoflurane anesthesia.

Refinement of the dose of doxapram to counteract the sedative effects of acepromazine in dogs.

OBJECTIVES: To evaluate the effectiveness of two doses of doxapram in reversing acepromazine sedation in dogs. METHODS: Using a crossover design, 10 adult mixed-breed dogs received 0·05 mg/kg acepromazine, intramuscularly (im) followed 30 minutes later by one of the three randomly determined treatments: 0·0625 mL/kg saline, intravenously (iv), 1·25 mg/kg doxapram, iv or 2·5 mg/kg doxapram, iv. Sedation scores were obtained by a single, blinded observer at 0, 15 and 30 minutes after acepromazine administration and at 5, 15 and 30 minutes after the treatment administration. RESULTS: The mean baseline sedation score of all the treatments was not different among treatments. All the dogs had a significant increase in sedation score at 30 minutes after acepromazine administration. Both the low and high doses of doxapram showed a significant decrease in sedation score compared to saline, but there was no significant difference between the two doses. Five dogs in the high dose group panted after treatment injection, and this was significantly more than in the low dose group. CLINICAL SIGNIFICANCE: Doxapram is effective in reducing the sedative effects of acepromazine over a short period of time. A dose of 1·25 mg/kg effectively decreases acepromazine sedation without causing panting.

The adrenocortical response of greater sage grouse (Centrocercus urophasianus) to capture, ACTH injection, and confinement, as measured in fecal samples.

Investigators of wildlife populations often utilize demographic indicators to understand the relationship between habitat characteristics and population viability. Assessments of corticosterone may enable earlier detection of populations at risk of decline because physiological adjustments to habitat disturbance occur before reproductive diminutions. Noninvasive methods to accomplish these assessments are important in species of concern, such as the greater sage grouse (GRSG). Therefore, we validated a radioimmunoassay that measures immunoreactive corticosterone metabolites (ICM) in fecal samples and used it to characterize the adrenocortical response of 15 GRSG exposed to capture, intravenous injection of 50 IU/kg adrenocorticotrophic hormone (ACTH) or saline, and 22 h of confinement. Those animals injected with ACTH exhibited a more sustained (P = 0.0139) and less variable (P = 0.0012) response than those injected with saline, indicating different levels of adrenocortical activity. We also found that potential field-collection protocols of fecal samples did not alter ICM concentrations: samples held at 4 degrees C for up to 16 h contained similar levels of ICM as those frozen (-20 degrees C) immediately. This study demonstrates a multiphasic adrenocortical response that varied with the level of stimulation and indicates that the assay used to measure this phenomenon is applicable for studies of wild GRSG.

Sample size and statistical power in the small-animal analgesia literature.

OBJECTIVE: To document the power and required sample sizes to achieve certain treatment objectives in the veterinary analgesia literature. METHODS: Pubmed's MEDLINE database and selected journals were searched. Only publications produced between 1994 and 2004 that reported 'no difference' between experimental groups in the abstract, results or conclusion sections and those that were randomised, prospective and blinded were reviewed. The data reported in the publications were then subjected to power analyses to determine the power and necessary sample size (to achieve a power of 0.8) to allow detection of 20 per cent, 50 per cent and 80 per cent treatment effects. RESULTS: Twenty-two studies provided sufficient data for analysis. Five out of 22 (23 per cent) had sufficient power to detect a 20 per cent treatment effect, 12 of 22 (54 per cent) had sufficient power to detect a 50 per cent treatment effect and 18 of 22 (82 per cent) had sufficient power to detect an 80 per cent treatment effect. The mean number of animals required per group to document a 20 per cent, 50 per cent and 80 per cent treatment effect were 90, 15 and 7, respectively. CLINICAL SIGNIFICANCE: Publications that report no significant difference between analgesic regimens may have committed a Type II error. The reader may inappropriately conclude that there is no difference between treatments when there may, in fact, be a superior analgesic regimen. Clinical practice based on the principles of evidence-based medicine could therefore result in suboptimal care for patients.

Chondrolysis and joint destruction secondary to snake envenomation.

Although snakebite injuries to the hand are common, intra-articular envenomation has rarely been reported. In this article, we describe a patient who was bitten by a rattlesnake and whose left-index-finger distal interphalangeal joint sustained intra-articular envenomation that resulted in aseptic chondrolysis and severe joint destruction 1.5 years later. Multiple cultures and biopsies were negative, and histology was consistent with nonspecific degenerative changes secondary to necrosis of the articular cartilage from retained toxins. The patient chose arthrodesis; 24 months postoperatively, he was pain-free and had returned to work.

Functional cystic thyroid adenoma in a cat.

A 9-year-old cat with hyperthyroidism was referred for radioactive iodine treatment. The cat also had a ventral cervical mass that the owners reported had been present for several years and had increased in size during the past few weeks. On physical examination, the mass was found to have caused lateral displacement of the trachea, esophagus, jugular vein, and common carotid artery. The mass was aspirated and was determined to be cystic in nature. Concentrations of thyroid hormones in the cystic fluid were similar to serum concentrations, and nuclear scintigraphy revealed thyroactive tissue lining the cyst wall. Magnetic resonance imaging suggested that the cyst originated from the right lobe of the thyroid gland. The cat was treated with sodium iodide I 131 but died 4 days later, presumably as a result of aspiration of gastric or esophageal contents. A necropsy was not performed, but histologic examination of a biopsy specimen of the mass indicated that it was a cystic thyroid adenoma.

Serodiagnosis of human granulocytic ehrlichiosis by using novel combinations of immunoreactive recombinant proteins.

A panel of seven recombinant antigens, derived from Ehrlichia phagocytophila (the agent of human granulocytic ehrlichiosis), was evaluated by class-specific enzyme-linked immunosorbent assays (ELISAs) for utility in the diagnosis of the infection. Fourteen genomic fragments, obtained by serologic expression screening, contained open reading frames (ORFs) encoding 16 immunodominant antigens. Eleven of these antigens were members of the major surface protein (MSP) multigene family. Alignment of their predicted protein sequences revealed a pattern of conserved sequences, which contained short direct repeats, flanking a variable region. In addition, two genomic clones contained two and three MSP ORFs, respectively, indicating that these genes are clustered in tandem copies. The implications for this pattern of both genomic and protein arrangements in antigenic variations of MSPs and in their utilities in a diagnostic assay are discussed. In addition to two MSP recombinant antigens (rHGE-1 and -3) and a fusion protein of these antigens (rErf-1), five further recombinants were evaluated by ELISA. Two of these antigens (rHGE-14 and -15) were novel, while a third (rHGE-2), with no known function, has been described. The final two recombinant antigens (rHGE-9 and -17) represent overlapping segments of the ankyrin gene (ank). The addition of rHGE-9 ELISA data resulted in the detection of 78% (21 of 27) of acute-phase sera. When serologic data for all recombinants are combined, 96.2% (26 of 27) of convalescent-phase patient serum samples and 85.2% (23 of 27) of acute-phase patient serum samples are detected, indicating the potential of these antigens for use in the development of a rapid serologic assay for the detection of E. phagocytophila infection.

The role of midcarpal arthroscopy in the diagnosis of disorders of the wrist.

The findings of midcarpal versus radiocarpal arthroscopic examinations were compared in the diagnosis of a variety of wrist pathology in 89 patients. During 15 months 89 midcarpal arthroscopic examinations were performed in conjunction with radiocarpal arthroscopic examinations. Eighty-one wrists underwent arthroscopy for acute or chronic intracarpal instability. Eight wrists underwent arthroscopy for arthroscopy-assisted intra-articular distal radius fracture reduction. In the acute wrist instability group midcarpal arthroscopy added to the radiocarpal diagnosis in 21 of 26 (82%) of the wrists. In the chronic wrist instability group midcarpal arthroscopy added to the radiocarpal diagnosis in 46 of 55 (84%) of the wrists. In the distal radius group 5 of 8 wrists had additional pathology on the midcarpal arthroscopy examination, leading to additional surgical intervention. These results demonstrate that midcarpal arthroscopy added statistically significant information to the radiocarpal examination compared with wrist arthroscopy performed without a midcarpal examination.

Gestational attenuation of Lyme arthritis is mediated by progesterone and IL-4.

Infection of different strains of laboratory mice with the agent of Lyme disease, Borrelia burgdorferi, results in arthritis, the severity of which has been correlated with the dominance of Th1 cytokines. In this study, we demonstrate that changes in B. burgdorferi-specific immunologic responses associated with pregnancy can alter the outcome of Lyme arthritis in mice. Whereas nonpregnant female C3H mice consistently developed severe Lyme arthritis, pregnant mice had a marked reduction in arthritis severity that was associated with a slight reduction in IFN-gamma and markedly increased levels of IL-4 production by B. burgdorferi-specific T cells. Similar reductions in arthritis severity and patterns of cytokine production were observed in nonpregnant, progesterone-implanted mice. Ab neutralization of IL-4 in progesterone-implanted mice resulted in severe arthritis. Our results are consistent with the known shift toward Th2 cytokine expression at the maternal-fetal interface, and are the first to show a pregnancy-related therapeutic effect in an infectious model.

Necrotizing fasciitis as complication of injection into greater trochanteric bursa.

Necrotizing fasciitis is a limb- and life-threatening soft-tissue infection that frequently involves the extremities. This article describes the first case of necrotizing fasciitis developing from a single steroid injection of the greater trochanteric bursa. Despite early resuscitation and aggressive surgical management that included a hip disarticulation, the patient expired. Potential contributing factors are reviewed.

Results of anterior cruciate ligament reconstruction in the adolescent female.

This study evaluated the functional results and complications of anterior cruciate ligament (ACL) surgery in adolescent females. We studied 22 consecutive female patients younger than 20 years who underwent arthroscopic ACL reconstruction. Average follow-up was 31 months. One hundred percent of the patients were satisfied. Seven patients returned to intercollegiate or high school sports. The mean Lysholm score was 94, and the International Knee Documentation Committee score was 40% normal, 60% nearly normal. KT-1000 arthrometer side-to-side differences were

Quantitative detection of Borrelia burgdorferi with a microtiter-based competitive polymerase chain reaction assay.

BACKGROUND: The current understanding of the inflammation associated with Lyme disease directly involves infection caused by Borrelia burgdorferi within specific target tissues, accompanied by a significant host immunologic component driving the inflammatory process. The measurement of spirochetal tissue burden may thus be useful for studying animal models of Lyme disease pathogenesis. Widely available methods based on the culture of spirochetes from tissues do not provide quantitative information. METHODS: We developed and evaluated a quantitative-competitive polymerase chain reaction assay based on amplification of the B. burgdorferi flagellin gene. The assay makes use of a competitive internal standard and a commercially available enzyme-linked immunosorbent assay detection kit. RESULTS AND CONCLUSION: The assay clearly discriminated between infected and uninfected mouse tissues, and an accurate quantitation range of 500 to 20,000 spirochetes per milligram of tissue was obtained. C3H mice were shown to harbor greater amounts of spirochetal genomic DNA than BALB/c mice. Normalization of samples by tissue weight and genomic DNA content both provided acceptable results. These data indicate this assay can be used to provide reliable and meaningful measurements of spirochetal infectious burden, which will be extremely useful for the study of Lyme disease pathogenesis in the murine model.

Evaporation of Accretion Disks around Black Holes: The Disk-Corona Transition and the Connection to the Advection-dominated Accretion Flow.

We apply the disk-corona evaporation model (Meyer & Meyer-Hofmeister) originally derived for dwarf novae to black hole systems. This model describes the transition of a thin cool outer disk to a hot coronal flow. The mass accretion rate determines the location of this transition. For a number of well-studied black hole binaries, we take the mass flow rates derived from a fit of the advection-dominated accretion flow (ADAF) model to the observed spectra (for a review, see Narayan, Mahadevan, & Quataert) and determine where the transition of accretion via a cool disk to a coronal flow/ADAF would be located for these rates. We compare this with the observed location of the inner disk edge, as estimated from the maximum velocity of the Halpha emission line. We find that the transition caused by evaporation agrees with this determination in stellar disks. We also show that the ADAF and the "thin outer disk + corona" are compatible in terms of the physics in the transition region.

Population dynamics of a naturally occurring heterogeneous mixture of Borrelia burgdorferi clones.

Two unique isolates of Borrelia burgdorferi, differing in plasmid content and outer surface protein C expression, were cultured on sequential captures of a single free-living Peromyscus leucopus mouse and were examined for differences in transmissibility. Both isolates were transmissible from inoculated C.B-17 mice to larval Ixodes scapularis ticks and, subsequently, from infected nymphal ticks to C3H/HeJ mice. Plasmid and protein analyses suggested that the original isolates were a mixed population of B. burgdorferi, and cloning by limiting dilution resulted in the identification of two clonal groups. In addition to being heterogeneous in plasmid and genomic macrorestriction analyses, the clones varied with respect to the electrophoretic mobilities and antigenicity of their OspC proteins, as shown by their reactivity to a panel of monoclonal antibodies. Plasmid analysis of sequential isolates from C3H mice experimentally infected with the primary isolate or various mixtures of its subclones showed an apparently random fluctuation in clonal dominance in the majority of mice. Surprisingly, mice infected with each subclone were permissive to superinfection with the heterologous subclone, despite the presence of anti-B. burgdorferi antibodies at the time of the secondary challenge. These results show conclusively that mice captured at Lyme disease enzootic sites may be infected by mixed populations of genetically and antigenically distinct B. burgdorferi clones and that these infections can be acquired by coinfection or by sequential infection. The lack of cross-immunization between clones existing within a naturally occurring population may play a role in the maintenance of the genetic heterogeneity of B. burgdorferi in nature.