Pub Date : 2024-08-06DOI: 10.30802/AALAS-JAALAS-24-047
Amanda R Maxwell, Natalie J Castell, Jacqueline K Brockhurst, Eric K Hutchinson, Jessica M Izzi
Swine are widely used models in biomedical research due to their physiologic and anatomic similarities to humans. During transport from vendors to research facilities, pigs are subject to a number of stressors, including environmental, social, and stress as a result of deprivation from food and water. As stress can have a number of adverse psychologic and physiologic effects, an acclimation period, defined as the period of time that an animal has to adjust and stabilize in a new environment, is recommended. The literature indicates that swine should be conditioned to their new facility for 5 to 7 d prior to undergoing survival surgery; however, to date, there is no published scientific evidence to support this or any specific acclimation period for swine. To investigate whether a certain length acclimation period leads to decreased stress in swine, we measured 2 stress biomarkers, cortisol and chromogranin A (CgA), from the saliva of 12 naive Yorkshire swine (n = 6 males and 6 females) arriving at our facility for use in research protocols. Noninvasive saliva collection was performed on days 1, 3, 5, 7, 10, and 14 after arrival from the vendor (representing different acclimation periods). We hypothesized that longer acclimation periods would result in reduced levels of both cortisol and CgA, indicating reduced stress. Our data revealed that there was no statistical difference in cortisol levels over time (P = 0.8200), nor between the sexes (P = 0.9886) or individual animals (P = 0.6280). CgA, similarly to cortisol, showed no overall effect of time (P = 0.2017) or sex (P = 0.6598). For this analyte, individual animal was significant (P < 0.0001), which suggests high interanimal variation. Furthermore, there was a significant decrease (P = 0.0077) in salivary CgA from day 1 compared with day 14, suggesting that swine may benefit from an acclimation period of at least 14 d.
{"title":"Determination of an Acclimation Period for Swine in Biomedical Research.","authors":"Amanda R Maxwell, Natalie J Castell, Jacqueline K Brockhurst, Eric K Hutchinson, Jessica M Izzi","doi":"10.30802/AALAS-JAALAS-24-047","DOIUrl":"https://doi.org/10.30802/AALAS-JAALAS-24-047","url":null,"abstract":"<p><p>Swine are widely used models in biomedical research due to their physiologic and anatomic similarities to humans. During transport from vendors to research facilities, pigs are subject to a number of stressors, including environmental, social, and stress as a result of deprivation from food and water. As stress can have a number of adverse psychologic and physiologic effects, an acclimation period, defined as the period of time that an animal has to adjust and stabilize in a new environment, is recommended. The literature indicates that swine should be conditioned to their new facility for 5 to 7 d prior to undergoing survival surgery; however, to date, there is no published scientific evidence to support this or any specific acclimation period for swine. To investigate whether a certain length acclimation period leads to decreased stress in swine, we measured 2 stress biomarkers, cortisol and chromogranin A (CgA), from the saliva of 12 naive Yorkshire swine (<i>n</i> = 6 males and 6 females) arriving at our facility for use in research protocols. Noninvasive saliva collection was performed on days 1, 3, 5, 7, 10, and 14 after arrival from the vendor (representing different acclimation periods). We hypothesized that longer acclimation periods would result in reduced levels of both cortisol and CgA, indicating reduced stress. Our data revealed that there was no statistical difference in cortisol levels over time (<i>P</i> = 0.8200), nor between the sexes (<i>P</i> = 0.9886) or individual animals (<i>P</i> = 0.6280). CgA, similarly to cortisol, showed no overall effect of time (<i>P</i> = 0.2017) or sex (<i>P</i> = 0.6598). For this analyte, individual animal was significant (<i>P</i> < 0.0001), which suggests high interanimal variation. Furthermore, there was a significant decrease (<i>P</i> = 0.0077) in salivary CgA from day 1 compared with day 14, suggesting that swine may benefit from an acclimation period of at least 14 d.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141899261","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-30DOI: 10.30802/AALAS-JAALAS-24-045
Caileen R Moran, Thomas J Park, Rochelle Buffenstein, Sayan Chakrabarty, Matthew O Lindeblad, Jeffrey D Fortman, Cynthia R Adams
Unique characteristics of the naked mole-rat (NMR) have made it increasingly popular as a laboratory animal model. These rodents are used to study many fields of research including longevity and aging, cancer, circadian rhythm, pain, and metabolism. Currently, the analgesic dosing regimens used in the NMR mirror those used in other rodent species. However, there is no pharmacokinetic (PK) data supporting the use of injectable analgesics in the NMR. Therefore, we conducted 2 independent PK studies to evaluate 2 commonly used analgesics in the NMR: meloxicam (2 mg/kg SC) and buprenorphine (0.1 mg/kg SC). In each study, blood was collected at 8 time points after subcutaneous injection of meloxicam or buprenorphine (0 [predose], 0.25, 0.5, 1, 2, 4, 8, and 24 h). Three NMRs were used per time point for a total of 24 animals per PK study. Plasma concentrations of meloxicam were highest between 0.5 and 1 h postinjection. Levels remained above the extrapolated dog and cat therapeutic threshold levels (390 to 911 ng/mL) for at least 24 h. Plasma concentrations of buprenorphine were highest between 0.25 and 0.5 h postinjection. Levels remained above the human therapeutic threshold (1 ng/mL) for up to 21 h. No skin reactions were seen in association with injection of either drug. In summary, these data support dosing meloxicam (2 mg/kg SC) once every 24 h and buprenorphine (0.1 mg/kg SC) once every 8 to 12 h in the NMR. Further studies should be performed to evaluate the clinical efficacy of these drugs by correlating plasma concentrations with postoperative pain assessments.
{"title":"Pharmacokinetics of Injectable Meloxicam and Buprenorphine in the Naked Mole-Rat (<i>Heterocephalus glaber</i>).","authors":"Caileen R Moran, Thomas J Park, Rochelle Buffenstein, Sayan Chakrabarty, Matthew O Lindeblad, Jeffrey D Fortman, Cynthia R Adams","doi":"10.30802/AALAS-JAALAS-24-045","DOIUrl":"10.30802/AALAS-JAALAS-24-045","url":null,"abstract":"<p><p>Unique characteristics of the naked mole-rat (NMR) have made it increasingly popular as a laboratory animal model. These rodents are used to study many fields of research including longevity and aging, cancer, circadian rhythm, pain, and metabolism. Currently, the analgesic dosing regimens used in the NMR mirror those used in other rodent species. However, there is no pharmacokinetic (PK) data supporting the use of injectable analgesics in the NMR. Therefore, we conducted 2 independent PK studies to evaluate 2 commonly used analgesics in the NMR: meloxicam (2 mg/kg SC) and buprenorphine (0.1 mg/kg SC). In each study, blood was collected at 8 time points after subcutaneous injection of meloxicam or buprenorphine (0 [predose], 0.25, 0.5, 1, 2, 4, 8, and 24 h). Three NMRs were used per time point for a total of 24 animals per PK study. Plasma concentrations of meloxicam were highest between 0.5 and 1 h postinjection. Levels remained above the extrapolated dog and cat therapeutic threshold levels (390 to 911 ng/mL) for at least 24 h. Plasma concentrations of buprenorphine were highest between 0.25 and 0.5 h postinjection. Levels remained above the human therapeutic threshold (1 ng/mL) for up to 21 h. No skin reactions were seen in association with injection of either drug. In summary, these data support dosing meloxicam (2 mg/kg SC) once every 24 h and buprenorphine (0.1 mg/kg SC) once every 8 to 12 h in the NMR. Further studies should be performed to evaluate the clinical efficacy of these drugs by correlating plasma concentrations with postoperative pain assessments.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11467880/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141857468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-29DOI: 10.30802/AALAS-JAALAS-24-000028
Keely Nicole Wharton, Courtney A Walsh, Marlena Haulter, Dinesh Ekanayake, Dil Ekanayake-Alper
Guinea pigs have been integral as models used in biomedical research, making significant contributions to nutritional, auditory, immunologic, and hypersensitivity studies, and necessitating the routine need for sedation in laboratory settings. The ketamine-xylazine (KX) combination has been the standard sedation protocol for decades. However, due to the adverse effects and abuse potential of xylazine, this study explores the possibility of substituting xylazine with midazolam and examines the combined use of midazolam with ketamine and alfaxalone in female laboratory guinea pigs. Our findings indicate that KX facilitates the fastest induction and longest duration of sedation compared with other sedatives, including ketamine-midazolam (KM), which, despite its rapid induction, results in significantly shorter sedation durations. KX also ensures a deeper anesthetic depth and greater odds of loss of withdrawal and inguinal reflexes, in contrast to KM and alfaxalone-midazolam (AM), under which only 15% of the animals lost these reflexes. In terms of cardiopulmonary function, KM led to an increased heart rate attributed to elevated sympathetic activity. All 4 sedative protocols lead to respiratory depression, except KM, which causes minimal reduction. Adverse events varied, with 75% of animals experiencing injection site reactions after KX administration and 67% exhibiting regurgitation post-KM administration. No adverse events were reported for the AM combination, suggesting its safer profile. In conclusion, while KX remains the superior protocol for sedation due to its efficiency, reliability, and minimal impact on physiologic parameters, midazolam is not a preferable alternative to replace xylazine. Its increased sympathetic tone, hyperesthesia, and shorter action duration, coupled with a higher potential for adverse events, limit its suitability to combine with ketamine in guinea pig sedation. However, when midazolam is used in conjunction with safer alternatives like alfaxalone, it presents a viable sedation strategy, emphasizing the need for further research into optimizing sedative combinations for laboratory guinea pigs.
豚鼠一直是生物医学研究中不可或缺的模型,在营养学、听觉、免疫学和超敏反应研究中做出了重要贡献,因此在实验室环境中必须使用常规镇静剂。几十年来,氯胺酮-恶嗪(KX)组合一直是标准镇静方案。然而,由于恶嗪的不良反应和滥用潜力,本研究探讨了用咪达唑仑替代恶嗪的可能性,并研究了在雌性实验豚鼠中将咪达唑仑与氯胺酮和阿法沙龙联合使用的情况。我们的研究结果表明,与包括氯胺酮-咪达唑仑(KM)在内的其他镇静剂相比,KX 的诱导速度最快,镇静持续时间最长。KX 还能确保更深的麻醉深度和更高的失禁和腹股沟反射几率,而 KM 和阿法沙酮-咪达唑仑(AM)只有 15% 的动物会失去这些反射。在心肺功能方面,KM会导致交感神经活动升高而导致心率加快。除 KM 会导致呼吸抑制外,其他四种镇静剂都会导致呼吸抑制。不良反应各不相同,75%的动物在注射 KX 后出现注射部位反应,67%的动物在注射 KM 后出现反胃。AM 组合未出现任何不良反应,表明其安全性更高。总之,尽管 KX 因其高效、可靠和对生理参数影响最小而仍然是镇静的最佳方案,但咪达唑仑并不是取代羟嗪的理想选择。咪达唑仑的交感神经张力增高、过度兴奋、作用持续时间较短,再加上发生不良反应的可能性较高,限制了其与氯胺酮联合用于豚鼠镇静的适宜性。不过,如果将咪达唑仑与阿法沙龙等更安全的替代品结合使用,则是一种可行的镇静策略,这也强调了进一步研究优化实验室豚鼠镇静剂组合的必要性。
{"title":"Sedation Efficacy of Midazolam in Conjunction with Ketamine and Alfaxalone in Female Laboratory Guinea Pigs (<i>Cavia porcellus</i>).","authors":"Keely Nicole Wharton, Courtney A Walsh, Marlena Haulter, Dinesh Ekanayake, Dil Ekanayake-Alper","doi":"10.30802/AALAS-JAALAS-24-000028","DOIUrl":"10.30802/AALAS-JAALAS-24-000028","url":null,"abstract":"<p><p>Guinea pigs have been integral as models used in biomedical research, making significant contributions to nutritional, auditory, immunologic, and hypersensitivity studies, and necessitating the routine need for sedation in laboratory settings. The ketamine-xylazine (KX) combination has been the standard sedation protocol for decades. However, due to the adverse effects and abuse potential of xylazine, this study explores the possibility of substituting xylazine with midazolam and examines the combined use of midazolam with ketamine and alfaxalone in female laboratory guinea pigs. Our findings indicate that KX facilitates the fastest induction and longest duration of sedation compared with other sedatives, including ketamine-midazolam (KM), which, despite its rapid induction, results in significantly shorter sedation durations. KX also ensures a deeper anesthetic depth and greater odds of loss of withdrawal and inguinal reflexes, in contrast to KM and alfaxalone-midazolam (AM), under which only 15% of the animals lost these reflexes. In terms of cardiopulmonary function, KM led to an increased heart rate attributed to elevated sympathetic activity. All 4 sedative protocols lead to respiratory depression, except KM, which causes minimal reduction. Adverse events varied, with 75% of animals experiencing injection site reactions after KX administration and 67% exhibiting regurgitation post-KM administration. No adverse events were reported for the AM combination, suggesting its safer profile. In conclusion, while KX remains the superior protocol for sedation due to its efficiency, reliability, and minimal impact on physiologic parameters, midazolam is not a preferable alternative to replace xylazine. Its increased sympathetic tone, hyperesthesia, and shorter action duration, coupled with a higher potential for adverse events, limit its suitability to combine with ketamine in guinea pig sedation. However, when midazolam is used in conjunction with safer alternatives like alfaxalone, it presents a viable sedation strategy, emphasizing the need for further research into optimizing sedative combinations for laboratory guinea pigs.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11467886/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141794406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-26DOI: 10.30802/AALAS-JAALAS-24-000003
Tsung-Keng Chang, Chih-Hsuan Wang, Tzu-Yi Lin, Yu-Chia Su
Improving the effectiveness of mating schemes for large-scale production of mice is an ongoing challenge in animal facilities. Continuous mating, which requires fewer breeding cages than intermittent mating, has traditionally been used to take advantage of postpartum estrus for efficient production. However, the continuous mating scheme lacks flexibility because it cannot immediately accommodate the reduced needs of mice when production levels are high. In this study, we compared reproductive performance, fecal corticosterone metabolite (FCM) level as a stress indicator, and mouse mortality between the continuous trio (CT) and intermittent quad (IQ) mating schemes. The weaning rates in the IQ scheme were higher than those in the CT scheme (98.8% compared with 85.3%). The FCM levels in IQ female breeders were lower during the first 5 d after parturition than those in CT female breeders. The FCM levels in postpartum females housed with 2 adult mice were significantly higher on days 1, 3, and 5 after giving birth than those of females housed alone. This suggests that the presence of cage mates may induce stress responses in postpartum females. Increasing the individual cage area did not reduce the FCM levels of female breeders when accompanied by cage mates after parturition. In addition, the incidence of dystocia and mortality was lower in IQ breeders than in CT breeders. In summary, this breeding trial suggests that compared with the continuous mating scheme, the intermittent mating scheme improves the welfare of postpartum females with normal breeding performance in the C57BL/6JNarl production colony.
{"title":"Effects of Intermittent Harem Mating on Parturition-induced Stress and Success Rate of Weaning in C57BL/6JNarl Mice.","authors":"Tsung-Keng Chang, Chih-Hsuan Wang, Tzu-Yi Lin, Yu-Chia Su","doi":"10.30802/AALAS-JAALAS-24-000003","DOIUrl":"10.30802/AALAS-JAALAS-24-000003","url":null,"abstract":"<p><p>Improving the effectiveness of mating schemes for large-scale production of mice is an ongoing challenge in animal facilities. Continuous mating, which requires fewer breeding cages than intermittent mating, has traditionally been used to take advantage of postpartum estrus for efficient production. However, the continuous mating scheme lacks flexibility because it cannot immediately accommodate the reduced needs of mice when production levels are high. In this study, we compared reproductive performance, fecal corticosterone metabolite (FCM) level as a stress indicator, and mouse mortality between the continuous trio (CT) and intermittent quad (IQ) mating schemes. The weaning rates in the IQ scheme were higher than those in the CT scheme (98.8% compared with 85.3%). The FCM levels in IQ female breeders were lower during the first 5 d after parturition than those in CT female breeders. The FCM levels in postpartum females housed with 2 adult mice were significantly higher on days 1, 3, and 5 after giving birth than those of females housed alone. This suggests that the presence of cage mates may induce stress responses in postpartum females. Increasing the individual cage area did not reduce the FCM levels of female breeders when accompanied by cage mates after parturition. In addition, the incidence of dystocia and mortality was lower in IQ breeders than in CT breeders. In summary, this breeding trial suggests that compared with the continuous mating scheme, the intermittent mating scheme improves the welfare of postpartum females with normal breeding performance in the C57BL/6JNarl production colony.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11467875/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141768378","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01Epub Date: 2024-03-08DOI: 10.30802/AALAS-JAALAS-23-000124
Laura R Ghussn, André A Justo, Mariana C Sanches, Silvia Rg Cortopassi, Adriano B Carregaro
This study aimed to compare the minimum anesthetic concentration (MAC) of sevoflurane in green iguanas using elec- trical stimulation and tail clamping as noxious stimuli. Seven adult green iguanas (Iguana iguana) weighing 580 to 1,300 g were enrolled. Each iguana was anesthetized twice after a 1-week washout period, with MAC being determined using a tail clamp (MACt) or electrical stimulation (MACe ) techniques. After sevoflurane mask induction and endotracheal intubation, the fraction of expired sevoflurane (Fe 'Sevo) was maintained at 3.1% for 15 min before noxious stimulation. In a bracketing design, the subsequent Fe'Sevo values were increased or decreased by 10% after positive or negative responses, respectively. Each targeted Fe 'Sevo was kept constant for 15 min before stimulation. In MACt, the noxious stimulus involved closing a Kelly hemostatic curved forceps to the first ratchet at the base of the tail. At the same site, in MACe, 2 30 × 0.8-mm hypodermic needles inserted 1 cm apart were connected to an electrical stimulator set to deliver 30 mA at 50 Hz at a 6.5-ms interval. The hemostat and the needles were repositioned 2 cm distally and on alternate tail sides at each stimulation round. Individual MAC was obtained when 2 consecutive crossover events occurred (a positive response preceding a negative response or vice versa), with the MAC of each group represented by the average of the individual MAC values. Median (interquartile range) values for the sevoflurane MAC did not differ significantly between groups (2.2 [2.2 to 2.8%] in MACe and 2.2 [1.8 to 3.5%] in MACt ; P = 0.812). Time to anesthesia induction, time to MAC measurement, heart rate (HR), end-tidal carbon dioxide (ET'CO2), and cloacal temperature were not different between groups. Both the tail-clamping and the electrical stimulation techniques yielded resembling sevoflurane MAC values in green iguanas, which makes the tail clamp a reliable alternative to electrical stimulation-based MAC research in this species.
本研究旨在比较七氟醚在绿鬣蜥体内的最低麻醉浓度(MAC),采用电刺激和夹尾作为有害刺激。七只成年绿鬣蜥(Iguana iguana)体重在 580-1,300 克之间。每只绿鬣蜥在经过一周的冲洗期后都会被麻醉两次,并使用夹尾(MACt)或电刺激(MACe)技术测定MAC。在七氟烷面罩诱导和气管插管后,呼出七氟烷(Fe'Sevo)的比例在有害刺激前的 15 分钟内保持在 3.1%。在括号设计中,在出现阳性或阴性反应后,随后的 Fe'Sevo 值分别增加或减少 10%。每个目标 Fe'Sevo 值在刺激前 15 分钟保持不变。在 MACt 中,有害刺激包括将凯利止血弯钳夹在尾基部的第一个棘轮上。在 MACe 中的同一部位,将两根相距 1 厘米的 30 × 0.8 毫米皮下注射针连接到电刺激器上,设置为以 50 赫兹、6.5 毫秒间隔输出 30 毫安电流。在每轮刺激中,止血钳和针头在尾部两侧交替向远端移动 2 厘米。当发生 2 次连续交叉事件(阳性反应先于阴性反应或反之亦然)时,将获得单个 MAC 值,每组的 MAC 值由单个 MAC 值的平均值表示。七氟醚 MAC 中位值(四分位数间距)在各组间无显著差异(MACe 为 2.2 [2.2 至 2.8%],MACt 为 2.2 [1.8 至 3.5%];P = 0.812)。麻醉诱导时间、MAC测量时间、心率(HR)、潮气末二氧化碳(ET'CO₂)和泄殖腔温度在各组之间没有差异。在绿鬣蜥体内,夹尾技术和电刺激技术都能产生类似的七氟醚 MAC 值,因此在该物种中,夹尾技术是电刺激 MAC 研究的可靠替代方法。
{"title":"Comparison between a Tail Clamp and Electrical Stimulation for Sevoflurane Minimum Anesthetic Concentration Determination in Green Iguanas (<i>Iguana iguana</i>).","authors":"Laura R Ghussn, André A Justo, Mariana C Sanches, Silvia Rg Cortopassi, Adriano B Carregaro","doi":"10.30802/AALAS-JAALAS-23-000124","DOIUrl":"10.30802/AALAS-JAALAS-23-000124","url":null,"abstract":"<p><p>This study aimed to compare the minimum anesthetic concentration (MAC) of sevoflurane in green iguanas using elec- trical stimulation and tail clamping as noxious stimuli. Seven adult green iguanas (<i>Iguana iguana</i>) weighing 580 to 1,300 g were enrolled. Each iguana was anesthetized twice after a 1-week washout period, with MAC being determined using a tail clamp (MACt) or electrical stimulation (MACe ) techniques. After sevoflurane mask induction and endotracheal intubation, the fraction of expired sevoflurane (Fe 'Sevo) was maintained at 3.1% for 15 min before noxious stimulation. In a bracketing design, the subsequent Fe'Sevo values were increased or decreased by 10% after positive or negative responses, respectively. Each targeted Fe 'Sevo was kept constant for 15 min before stimulation. In MACt, the noxious stimulus involved closing a Kelly hemostatic curved forceps to the first ratchet at the base of the tail. At the same site, in MACe, 2 30 × 0.8-mm hypodermic needles inserted 1 cm apart were connected to an electrical stimulator set to deliver 30 mA at 50 Hz at a 6.5-ms interval. The hemostat and the needles were repositioned 2 cm distally and on alternate tail sides at each stimulation round. Individual MAC was obtained when 2 consecutive crossover events occurred (a positive response preceding a negative response or vice versa), with the MAC of each group represented by the average of the individual MAC values. Median (interquartile range) values for the sevoflurane MAC did not differ significantly between groups (2.2 [2.2 to 2.8%] in MACe and 2.2 [1.8 to 3.5%] in MACt ; <i>P</i> = 0.812). Time to anesthesia induction, time to MAC measurement, heart rate (HR), end-tidal carbon dioxide (ET'CO2), and cloacal temperature were not different between groups. Both the tail-clamping and the electrical stimulation techniques yielded resembling sevoflurane MAC values in green iguanas, which makes the tail clamp a reliable alternative to electrical stimulation-based MAC research in this species.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270046/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140066399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01Epub Date: 2024-03-12DOI: 10.30802/AALAS-JAALAS-23-000087
Lucia Mihalovičová, Veronika Kunšteková, Dávid Miláček, Andrej Feješ, Mária Tekeľová, Emese Renczés, Peter Celec, Veronika Borbélyová
The collection and examination method of vaginal smears is the standard for the determination of ovulation or phases of the estrous cycle of rodents used in research. However, this method is time consuming and may not be amenable to continual monitoring of a large number of animals. Infrared thermography has recently emerged as a noninvasive technique that requires relatively little handling of animals. The body temperature of rodents has been shown to correlate with the ocular surface temperature. This study aimed to evaluate the use of thermographic monitoring of the ocular surface for the identification of estrus in rats. Vaginal smears were collected from female Wistar rats (n = 22) for 14 consecutive days. Core body temperature was estimated by measuring ocular surface temperature using a thermal camera; vaginal temperature was measured using a digital thermometer. Average temperatures were calculated for each rat for each phase of the estrous cycle. The highest core body and vaginal temperature were measured during the estrus phase (37.2 ± 0.6 °C and 37.7 ± 0.6 °C, respectively). The temperatures then fell as the rat entered the diestrus phase (36.8 ± 0.5 °C and 37 ± 0.5 °C). The core body temperature was positively correlated with vaginal temperature (r = 0.697, P < 0.001). In conclusion, thermography is a less invasive method of determining estrus in rats as compared with vaginal smear collection. However, thermography is less accurate and requires at least a 12-d period of measurement.
{"title":"Infrared Thermal Imaging during the Estrous Cycle in Adult Wistar Rats.","authors":"Lucia Mihalovičová, Veronika Kunšteková, Dávid Miláček, Andrej Feješ, Mária Tekeľová, Emese Renczés, Peter Celec, Veronika Borbélyová","doi":"10.30802/AALAS-JAALAS-23-000087","DOIUrl":"10.30802/AALAS-JAALAS-23-000087","url":null,"abstract":"<p><p>The collection and examination method of vaginal smears is the standard for the determination of ovulation or phases of the estrous cycle of rodents used in research. However, this method is time consuming and may not be amenable to continual monitoring of a large number of animals. Infrared thermography has recently emerged as a noninvasive technique that requires relatively little handling of animals. The body temperature of rodents has been shown to correlate with the ocular surface temperature. This study aimed to evaluate the use of thermographic monitoring of the ocular surface for the identification of estrus in rats. Vaginal smears were collected from female Wistar rats (<i>n</i> = 22) for 14 consecutive days. Core body temperature was estimated by measuring ocular surface temperature using a thermal camera; vaginal temperature was measured using a digital thermometer. Average temperatures were calculated for each rat for each phase of the estrous cycle. The highest core body and vaginal temperature were measured during the estrus phase (37.2 ± 0.6 °C and 37.7 ± 0.6 °C, respectively). The temperatures then fell as the rat entered the diestrus phase (36.8 ± 0.5 °C and 37 ± 0.5 °C). The core body temperature was positively correlated with vaginal temperature (<i>r</i> = 0.697, <i>P</i> < 0.001). In conclusion, thermography is a less invasive method of determining estrus in rats as compared with vaginal smear collection. However, thermography is less accurate and requires at least a 12-d period of measurement.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270034/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140112544","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01Epub Date: 2024-03-20DOI: 10.30802/AALAS-JAALAS-23-000106
Peggy Yang, Stephanie Yang, Laura B Durham, Patrick A Lester, Daniel D Myers
Extended-release (ER) local anesthetics are often incorporated in multi-modal analgesia or as an alternative when the effect of systemic analgesics may confound research. In this study, we compared the analgesic efficacy of 2 ER bupivacaine anesthetics with different ER mechanisms, a slow-release bupivacaine-meloxicam polymer (BMP) and a sucrose acetate isobutyrate bupivacaine (SABER-B) system. We used a full-thickness unilateral skin incision porcine model to evaluate the efficacy of these 2 ER bupivacaine analgesics. Eighteen male swine were randomized into 3 groups: control (saline; n = 6), bupivacaine:meloxicam (10 mg/kg, 0.3 mg/kg; n = 6), and SABER-B (10 mg/kg; n = 6). After surgery, pigs were assessed for changes in body weight, salivary cortisol level, and response to von Frey testing at 1, 3, 6, 24, 48, 72, 96, 120, and 168 h. Body weight and salivary cortisol levels were not significantly different between groups. Based on the von Frey testing, the pigs that received analgesics showed a significantly higher withdrawal threshold of nociceptive stimulus than those that received saline at 1, 3, 6, and 24 h after the surgery. At 48 h after surgery, the SABER-B group had a significantly higher withdrawal threshold than the saline group. The withdrawal threshold was not significantly different from the baseline measurement on intact skin at 3 and 6 h after surgery in the BMP group or 1 and 3 h for the SABERB group. The analgesic effects of BMP were greatest at 3 and 6 h after surgery and that of SABER-B as 1 and 3 h SABER-B provided an earlier onset of analgesia and longer analgesia duration than did BMP. This study demonstrates that ER bupivacaine can provide pigs with 24 to 48 h of analgesia for incisional pain.
{"title":"Evaluation of Efficacy of 2 Extended-release Bupivacaine Products in a Porcine Model of Incisional Pain.","authors":"Peggy Yang, Stephanie Yang, Laura B Durham, Patrick A Lester, Daniel D Myers","doi":"10.30802/AALAS-JAALAS-23-000106","DOIUrl":"10.30802/AALAS-JAALAS-23-000106","url":null,"abstract":"<p><p>Extended-release (ER) local anesthetics are often incorporated in multi-modal analgesia or as an alternative when the effect of systemic analgesics may confound research. In this study, we compared the analgesic efficacy of 2 ER bupivacaine anesthetics with different ER mechanisms, a slow-release bupivacaine-meloxicam polymer (BMP) and a sucrose acetate isobutyrate bupivacaine (SABER-B) system. We used a full-thickness unilateral skin incision porcine model to evaluate the efficacy of these 2 ER bupivacaine analgesics. Eighteen male swine were randomized into 3 groups: control (saline; <i>n</i> = 6), bupivacaine:meloxicam (10 mg/kg, 0.3 mg/kg; <i>n</i> = 6), and SABER-B (10 mg/kg; <i>n</i> = 6). After surgery, pigs were assessed for changes in body weight, salivary cortisol level, and response to von Frey testing at 1, 3, 6, 24, 48, 72, 96, 120, and 168 h. Body weight and salivary cortisol levels were not significantly different between groups. Based on the von Frey testing, the pigs that received analgesics showed a significantly higher withdrawal threshold of nociceptive stimulus than those that received saline at 1, 3, 6, and 24 h after the surgery. At 48 h after surgery, the SABER-B group had a significantly higher withdrawal threshold than the saline group. The withdrawal threshold was not significantly different from the baseline measurement on intact skin at 3 and 6 h after surgery in the BMP group or 1 and 3 h for the SABERB group. The analgesic effects of BMP were greatest at 3 and 6 h after surgery and that of SABER-B as 1 and 3 h SABER-B provided an earlier onset of analgesia and longer analgesia duration than did BMP. This study demonstrates that ER bupivacaine can provide pigs with 24 to 48 h of analgesia for incisional pain.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270038/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140178439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01Epub Date: 2024-03-01DOI: 10.30802/AALAS-JAALAS-23-000056
Vanessa N Gris, Thomás R Crespo, Akihisa Kaneko, Munehiro Okamoto, Juri Suzuki, Jun-Nosuke Teramae, Takako Miyabe-Nishiwaki
Facial expressions have increasingly been used to assess emotional states in mammals. The recognition of pain in research animals is essential for their well-being and leads to more reliable research outcomes. Automating this process could contribute to early pain diagnosis and treatment. Artificial neural networks have become a popular option for image classification tasks in recent years due to the development of deep learning. In this study, we investigated the ability of a deep learning model to detect pain in Japanese macaques based on their facial expression. Thirty to 60 min of video footage from Japanese macaques undergoing laparotomy was used in the study. Macaques were recorded undisturbed in their cages before surgery (No Pain) and one day after the surgery before scheduled analgesia (Pain). Videos were processed for facial detection and image extraction with the algorithms RetinaFace (adding a bounding box around the face for image extraction) or Mask R-CNN (contouring the face for extraction). ResNet50 used 75% of the images to train systems; the other 25% were used for testing. Test accuracy varied from 48 to 54% after box extraction. The low accuracy of classification after box extraction was likely due to the incorporation of features that were not relevant for pain (for example, background, illumination, skin color, or objects in the enclosure). However, using contour extraction, preprocessing the images, and fine-tuning, the network resulted in 64% appropriate generalization. These results suggest that Mask R-CNN can be used for facial feature extractions and that the performance of the classifying model is relatively accurate for nonannotated single-frame images.
{"title":"Deep Learning for Face Detection and Pain Assessment in Japanese macaques (<i>Macaca fuscata</i>).","authors":"Vanessa N Gris, Thomás R Crespo, Akihisa Kaneko, Munehiro Okamoto, Juri Suzuki, Jun-Nosuke Teramae, Takako Miyabe-Nishiwaki","doi":"10.30802/AALAS-JAALAS-23-000056","DOIUrl":"10.30802/AALAS-JAALAS-23-000056","url":null,"abstract":"<p><p>Facial expressions have increasingly been used to assess emotional states in mammals. The recognition of pain in research animals is essential for their well-being and leads to more reliable research outcomes. Automating this process could contribute to early pain diagnosis and treatment. Artificial neural networks have become a popular option for image classification tasks in recent years due to the development of deep learning. In this study, we investigated the ability of a deep learning model to detect pain in Japanese macaques based on their facial expression. Thirty to 60 min of video footage from Japanese macaques undergoing laparotomy was used in the study. Macaques were recorded undisturbed in their cages before surgery (No Pain) and one day after the surgery before scheduled analgesia (Pain). Videos were processed for facial detection and image extraction with the algorithms RetinaFace (adding a bounding box around the face for image extraction) or Mask R-CNN (contouring the face for extraction). ResNet50 used 75% of the images to train systems; the other 25% were used for testing. Test accuracy varied from 48 to 54% after box extraction. The low accuracy of classification after box extraction was likely due to the incorporation of features that were not relevant for pain (for example, background, illumination, skin color, or objects in the enclosure). However, using contour extraction, preprocessing the images, and fine-tuning, the network resulted in 64% appropriate generalization. These results suggest that Mask R-CNN can be used for facial feature extractions and that the performance of the classifying model is relatively accurate for nonannotated single-frame images.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270042/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140013859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01Epub Date: 2024-03-12DOI: 10.30802/AALAS-JAALAS-23-000107
Rachel R Howie, Michael M McKinney, Nicholas M Tataryn, Allysa L Cole, William D Dupont, Tzushan S Yang, Katherine N Gibson-Corley
Despite the major use of mice in biomedical research, little information is available with regard to identifying their postmortem changes and using that information to determine the postmortem interval (PMI), defined as the time after death. Both PMI and environmental conditions influence decomposition (autolysis and putrefaction) and other postmortem changes. Severe decomposition compromises lesion interpretation and disease detection and wastes limited pathology resources. The goal of this study was to assess postmortem changes in mice in room temperature cage conditions and under refrigeration at 4 °C to develop gross criteria for the potential value of further gross and histologic evaluation. We used 108 experimentally naïve C57BL/6 mice that were humanely euthanized and then allocated them into 2 experimental groups for evaluation of postmortem change: room temperature (20 to 22 °C) or refrigeration (4 °C). PMI assessments, including gross changes and histologic scoring, were performed at hours 0, 4, 8, and 12 and on days 1 to 14. Factors such as temperature, humidity, ammonia in the cage, and weight change were also documented. Our data indicates that carcasses held at room temperature decomposed faster than refrigerated carcasses. For most tissues, decomposition was evident by 12 h at room temperature as compared with 5 d under refrigeration. At room temperature, gross changes were present by day 2 as compared with day 7 under refrigeration. Mice at room temperature lost 0.78% of their baseline body weight per day as compared with 0.06% for refrigerated mice (95% CI for difference 0.67% to 0.76%, P < 0.0005). This study supports the consideration of temperature and PMI as important factors affecting the suitability of postmortem tissues for gross and histologic evaluation and indicates that storage of carcasses under refrigeration will significantly slow autolysis.
{"title":"Determination of Postmortem Interval in Mice.","authors":"Rachel R Howie, Michael M McKinney, Nicholas M Tataryn, Allysa L Cole, William D Dupont, Tzushan S Yang, Katherine N Gibson-Corley","doi":"10.30802/AALAS-JAALAS-23-000107","DOIUrl":"10.30802/AALAS-JAALAS-23-000107","url":null,"abstract":"<p><p>Despite the major use of mice in biomedical research, little information is available with regard to identifying their postmortem changes and using that information to determine the postmortem interval (PMI), defined as the time after death. Both PMI and environmental conditions influence decomposition (autolysis and putrefaction) and other postmortem changes. Severe decomposition compromises lesion interpretation and disease detection and wastes limited pathology resources. The goal of this study was to assess postmortem changes in mice in room temperature cage conditions and under refrigeration at 4 °C to develop gross criteria for the potential value of further gross and histologic evaluation. We used 108 experimentally naïve C57BL/6 mice that were humanely euthanized and then allocated them into 2 experimental groups for evaluation of postmortem change: room temperature (20 to 22 °C) or refrigeration (4 °C). PMI assessments, including gross changes and histologic scoring, were performed at hours 0, 4, 8, and 12 and on days 1 to 14. Factors such as temperature, humidity, ammonia in the cage, and weight change were also documented. Our data indicates that carcasses held at room temperature decomposed faster than refrigerated carcasses. For most tissues, decomposition was evident by 12 h at room temperature as compared with 5 d under refrigeration. At room temperature, gross changes were present by day 2 as compared with day 7 under refrigeration. Mice at room temperature lost 0.78% of their baseline body weight per day as compared with 0.06% for refrigerated mice (95% CI for difference 0.67% to 0.76%, <i>P</i> < 0.0005). This study supports the consideration of temperature and PMI as important factors affecting the suitability of postmortem tissues for gross and histologic evaluation and indicates that storage of carcasses under refrigeration will significantly slow autolysis.</p>","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270044/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140112543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-01DOI: 10.30802/AALAS-JAALAS-24-063
M A Suckow, M T Fallon
{"title":"AALAS Journals: Continual Adaptation to Meet Changing Environments.","authors":"M A Suckow, M T Fallon","doi":"10.30802/AALAS-JAALAS-24-063","DOIUrl":"10.30802/AALAS-JAALAS-24-063","url":null,"abstract":"","PeriodicalId":94111,"journal":{"name":"Journal of the American Association for Laboratory Animal Science : JAALAS","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11270040/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141904028","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}