Journal of the American Association for Laboratory Animal Science : JAALAS最新文献

Schistosomiasis, a parasitic disease caused by trematodes of the genus Schistosoma, was eliminated on the island of Saint Kitts in the 1950s after an intense program that targeted the snail intermediate host and improved sanitation. However, recently, 3 cases of schistosomiasis were identified in green monkeys (Chlorocebus sabaeus) imported from Saint Kitts over a period of 5 months from December 2023 to April 2024. The 3 cases each had hepatic manifestations of the disease. In addition, one animal had disseminated disease affecting the cerebrum, cerebellum, brainstem, and lung and is the first described case of neuroschistosomiasis in a non-human primate (NHP) due to infection with Schistosoma mansoni.

The Guide for the Care and Use of Laboratory Animals specifies that sipper tubes require weekly sanitization, although reduced frequency for sterile, disposable caging components may be justified with performance-based assessments; therefore, extending bottle duration beyond 1 week, and replacing instead at a lower volume limit, may be acceptable if it does not compromise mouse health or water quality. Weekly bottle change for sterile, disposable bottles results in excessive waste of both water and plastic-bottles are typically more than half full at 7 days. A volume-based replacement schedule is a visual alternative to weekly changes for systems using sterile, disposable bottles, reducing the number of bottles processed and facilitating operations by allowing spot changes without the need to date or track bottles. Furthermore, the gravity-drip design of Innovive's Aquavive bottle minimizes contamination, suggesting that water quality and cleanliness may be maintained for longer durations. To assess the impact of a volume-based replacement schedule on mouse health and water quality, C57BL/6NCrl mice at varying housing densities were monitored for changes in animal weight and mean water consumption. At bottle replacement, packed cell volume was collected from individual mice as a marker of hydration status, and water quality was assessed by visual inspection, culture for Escherichia coli and coliform bacteria, and total microbial count. Baseline measurements were collected over 7 days, followed by a volume-based replacement period, where bottles remained on the cage until they reached 100 mL (13-47 days). No significant differences were observed in animal body weight, body condition, water consumption, or packed cell volume, regardless of cage density or the amount of time the bottle was deployed. Microbial analysis showed no bacterial growth in any bottle, and visual inspection showed no turbidity or cloudiness. Based on this information, our institution allowed prefilled disposable, acidified water bottles to be maintained well beyond 7 days, using a volume-based replacement at 100 mL.

The Jamaican fruit bat (Artibeus jamaicensis; JFB) is a natural host and current experimental model for many viruses, including Middle East respiratory syndrome virus, dengue virus, Zika virus, rabies virus, influenza virus, tacaribe virus, and most recently SARS-CoV-2, due to their unique immune systems, which allow the harboring and transmission of disease without developing significant clinical disease themselves. In these studies, disease impact can be measured using changes in serum biochemical and protein electrophoretic blood values. However, no currently established reference intervals for JFB exist. In this study, we aimed to define these baseline parameters from our closed bat colony and determine sex differences, if any. We hypothesized that many chemistry values would be similar to other species of frugivorous bats with elevated creatine kinase and glucose due to hand capture and that sex differences would be minimal. One hundred thirty-four adult bats (62 males and 72 females) were randomly selected from an apparently healthy captive population of JFB for isoflurane euthanasia and blood collection by cardiocentesis. Serum samples were routinely processed using commercially available methods. Reference intervals for the total population and both sexes were established using the Reference Value Advisor 2.1 macro for Excel and the nonparametric method in accordance with current guidelines. When compared against reference values for other frugivorous bat species, JFB most notably had increased ALT, AST, GGT, and potassium values. Higher phosphorus and ALP levels may be attributed to sampling of juveniles, while elevated creatine kinase and glucose are secondary to capture. Males had considerably higher cholesterol, while females had higher glucose and γ-globulin. This information on serum biochemical values adds to our knowledge of the normal physiologic parameters of this species and will serve as a useful guide for future studies performed on Jamaican fruit bats.

Diabetes is a global health concern, with increasing prevalence attributed to factors such as obesity and sedentary lifestyles. Nonhuman primates (NHPs), particularly rhesus macaques (Macaca mulatta), serve as valuable models for studying type 2 diabetes mellitus due to their physiologic similarities to humans. However, there are currently no established normal ranges for glycated hemoglobin (A1C) in this species. This study aimed to determine normal A1C values in healthy, nonobese adult rhesus macaques to establish a reference for future diabetes research. A total of 210 Indian origin rhesus macaques (128 males, 82 females) 5-10 years of age were sampled. A1C was measured using the A1CNow+ kit, and blood glucose levels were assessed via a point-of-care glucometer and clinical laboratory analysis. Statistical analyses were performed using R, including a Shapiro-Wilks test for normality, regression analyses, and correlation coefficients. The mean A1C value was 5.92% (range, 4.4%-9.9%), with males exhibiting a mean of 6.07% and females 5.69%. No significant correlations were found between A1C and blood glucose levels, weight, body condition score, or age. However, males had significantly higher A1C levels than females (P = 0.004). Excluding outliers revealed a significant interaction between sex and weight (P = 0.03). The established mean A1C value for healthy adult rhesus macaques is higher than previously reported values for NHPs and human standards. This study provides a critical reference for A1C levels in rhesus macaques, facilitating future diabetes research and improving understanding of type 2 diabetes mellitus in both humans and NHPs.

Hemangiosarcoma is a malignant neoplasm of vascular endothelial cell origin that is rare in nonhuman primates (NHPs) and humans. This report describes the clinical, gross, and histopathologic findings of metastatic hemangiosarcoma in a rhesus macaque. A 4.8-year-old female Indian-origin rhesus macaque presented to the Tulane National Biomedical Research Center clinic with right hindlimb lameness and poor body condition. On physical examination, there was significant muscle atrophy of the right leg and pelvis. Radiographs revealed severe bone degeneration and lysis of the right tibia with pulmonary nodules. On necropsy, the right tibia was markedly thickened at least two times the normal size. Multifocal, 1- to 7-mm-diameter dark red nodules were present in the periosteum, compact cortical bone, and medullary cavity. Multifocal dark red nodules measuring 1-10 mm were present in the liver and lung. Histologically, the nodules were composed of neoplastic endothelial cells forming irregular vascular clefts and anastomosing vascular channels. Neoplastic cells often wrapped collagenous stroma. Neoplastic cells stained positive with CD31, as well as with von Willebrand factor immunohistochemical stains. Hemangiosarcoma in NHPs is exceptionally rare. To our knowledge, this represents the first case of metastatic hemangiosarcoma originating in bone in an NHP.

Total intravenous anesthesia (TIVA) is an alternative to inhalant anesthesia when inhalant anesthesia is unavailable or contraindicated. This study investigated the anesthetic efficacy of tiletamine-zolazepam (TZ) through continuous rate infusion in sheep undergoing a 120-minute noninvasive imaging procedure. We hypothesized that the TZ continuous rate infusion would provide effective general anesthesia for imaging. Six male Dorset sheep were sedated with 4-6 mg/kg TZ intramuscularly, intubated, and maintained on 5-15 mg/kg/h TZ intravenous continuous rate infusion. Measured anesthetic parameters included heart rate, oxygen saturation (%SpO2), end-tidal carbon dioxide (ETCO2), body temperature, and direct arterial blood pressure (systolic, diastolic, and mean); blood gas analysis was performed during anesthesia. Time to extubation and standing (recovery) were measured. Other clinical observations (thrashing, activity, vocalization, and general appearance) were also assessed throughout recovery. Heart rate, %SpO2, ETCO2, body temperature, and direct arterial blood pressure were stable throughout imaging anesthesia. Time to extubation and standing (recovery) were 25 ± 6.5 and 34 ± 8.0 minutes, respectively. No abnormal clinical observations were noted. These data suggest that TZ TIVA provides effective general anesthesia for up to 120 minutes of noninvasive imaging.

This study aimed to establish a comprehensive and accurate numerical chest X-ray radiograph (CXR) scoring system in cynomolgus macaques by using image intensity values from healthy, tuberculosis (TB)-free animals as references. The CXRs were obtained in both dorsoventral and lateral postures from 90 macaques and viewed by the RadiAnt DICOM Viewer software version 2023.1. The mean and maximum intensity values were analyzed and showed significant differences between sex (male and female) and age class (juvenile and subadult/adult), varying based on body sizes. The cutoff values were, therefore, set separately and were tested for accuracy in detecting TB status in 18 naturally Mycobacterium tuberculosis-infected macaques, which were assessed for active tuberculosis infection (ATBI) using Xpert MTB/RIF Ultra at least once during a 12-month follow-up. Only the cutoff values of maximum lateral image intensity (MLIs) correctly identified TB infection in 100% of cases. Thus, the MLIs were selected to follow up on the development of TB lesions in those 18 Mycobacterium tuberculosis-infected macaques. The lateral digital radiograph was divided further into 9 areas, and the MLIs can predict the progression of TB lesions, which were most likely located in the dorsal part of the cranial lung lobe between thoracic vertebrae 1 (T1) to T4. Finally, the CXR results of another group of 8 Mycobacterium tuberculosis-exposed macaques, whose TB status was either uninfected, latent, or ATBI, were compared between a blind test by an expert radiologist and our established CXR scoring system. The blind test results showed 62.5% (5/8) agreement with our scoring system. This suggests that the CXR-MLI scoring system can be used as a supplementary tool for TB diagnosis in cynomolgus macaques.

Rabbits are commonly used as surgical models, thus requiring analgesics for painful procedures and optimal animal welfare. Buprenorphine, a partial µ opioid, is commercially available in various concentrations and sustained-release formulations and has historically been used as an analgesic in rabbits. A topical long-acting buprenorphine formulation (Zorbium, Bup-TP) has been approved for analgesic use in cats but has not yet been evaluated in rabbits. The present study evaluated the plasma concentrations and pharmacokinetic parameters of Bup-TP in New Zealand white rabbits (Oryctolagus cuniculus). Healthy adult male (n = 4) and female (n = 4) New Zealand white rabbits were used in a randomized crossover design and received a single high (7 mg/kg) and low (3 mg/kg) dose of Bup-TP. In this study, Bup-TP achieved a plasma blood concentration >0.25 ng/mL starting at 0.5 hours after dosing that was maintained up to 72 hours after dosing in adult New Zealand white rabbits. Compared with baseline, fecal and urinary output were reduced for an average of 3.5 days after dosing; food consumption was reduced for an average of 10 days after dosing. All resolved with time and supportive care. No lesions were grossly visible on any rabbit at site of application. Bup-TP may be an effective, long-lasting, and noninvasive method of providing analgesia in rabbits. Future study is recommended to optimize dosing and procedural analgesic efficacy.

Nude mice were inoculated with a nonpathogenic Corynebacterium bovis isolate (NPI) or Corynebacterium amycolatum to assess whether either could prevent skin lesions following inoculation with a pathogenic C. bovis isolate (PI). Crl:NU(NCr)-Foxn1nu mice (n = 6/group) were randomized into 6 groups: NPI (108 colony-forming units [CFU]); C. amycolatum (108 CFU); NPI or C. amycolatum followed 2 weeks later by PI (104 CFU); and negative and positive controls receiving sterile media or the PI (104 CFU), respectively. Colonization was assessed biweekly using isolate-specific PCR assays. Skin lesions were scored 0 to 5 daily for 4 or 6 weeks, at which point skin biopsies were collected, evaluated, and scored. No mice inoculated with the NPI and subsequently infected with the PI developed clinical signs, nor was a significant amount of the PI detected by PCR. Mice inoculated with C. amycolatum before the PI developed milder, delayed skin lesions reaching a significantly lower mean peak clinical score (MPCS; 1.2 ± 0.4) as compared with the positive control (MPCS 2.5 ± 0.5). The C. amycolatum-inoculated mice with and without PI had similar total histopathology scores, both of which were significantly higher than those for the mice inoculated with the NPI followed by the PI. These results led to evaluation of a practical exposure strategy in which nude mice (n = 6/group) were housed on NPI seeded bedding (SB) for 3 or 7 days prior to PI administration; mice housed on C. bovis-free bedding served as controls. Only 1 of 12 mice housed on SB receiving the PI developed Corynebacterium-associated hyperkeratosis (peak score of 4), whereas all unvaccinated mice receiving the PI developed Corynebacterium-associated hyperkeratosis (MPCS 2.83 ± 0.69). The PI was not detected in the SB + PI groups until 21 days postinfection with the PI. There was no significant difference in total histopathology scores across groups, but the histopathology scores were lower in mice receiving the SB.