Mechanogenetics for the remote and noninvasive control of cancer immunotherapy.

While cell-based immunotherapy, especially chimeric antigen receptor (CAR)-expressing T cells, is becoming a paradigm-shifting therapeutic approach for cancer treatment, there is a lack of general methods to remotely and noninvasively regulate genetics in live mammalian cells and animals for cancer immunotherapy within confined local tissue space. To address this limitation, we have identified a mechanically sensitive Piezo1 ion channel (mechanosensor) that is activatable by ultrasound stimulation and integrated it with engineered genetic circuits (genetic transducer) in live HEK293T cells to convert the ultrasound-activated Piezo1 into transcriptional activities. We have further engineered the Jurkat T-cell line and primary T cells (peripheral blood mononuclear cells) to remotely sense the ultrasound wave and transduce it into transcriptional activation for the CAR expression to recognize and eradicate target tumor cells. This approach is modular and can be extended for remote-controlled activation of different cell types with high spatiotemporal precision for therapeutic applications.

Impact of endotracheal tube size and cuff pressure on tracheal and laryngeal mucosa of adult horses.

OBJECTIVE: To assess the effects of two sizes of silicone endotracheal tubes with internal diameter 26 mm (ETT26) and 30 mm (ETT30) inflated to minimum occlusive volume on tracheal and laryngeal mucosa of adult horses anesthetized for 2 hours with isoflurane. STUDY DESIGN: Prospective, randomized, blinded, crossover experimental study. ANIMALS: A total of eight healthy adult mares. METHODS: Upper airway endoscopy and ultrasound measurements of internal tracheal diameter were performed the day before anesthesia. Horses were anesthetized and orotracheally intubated with ETT26 or ETT30. Ease of intubation was scored. The cuff was inflated in 10 mL increments to produce a seal. Final volume of air used and intracuff (IC) pressure (measured by pressure transducer) were recorded. At the end of anesthesia, a manometer was used to measure IC pressure and these measurements compared against measurements from the pressure transducer. Laryngeal and tracheal mucosa were assessed via endoscopy and assigned a score 0-3 before anesthesia, and at 2 and 24 hours following extubation. RESULTS: Data are from seven horses because one horse with laryngeal hemiplegia was excluded. Mean tracheal ultrasound measurement was 3.5 ± 0.4 cm. No significant differences were noted between endotracheal tube sizes for intubation score, IC pressures, inflation volumes or tracheal or laryngeal injury scores at any time point. IC pressure measured by manometer was slightly higher than that by transducer (+1.0 ± 2.8 mmHg). CONCLUSIONS AND CLINICAL RELEVANCE: Results identified no clear advantage of one endotracheal tube size over the other in the population of horses studied, when endotracheal intubation is properly applied and IC pressure is carefully monitored. However, given that ETT26 was associated with the highest observed IC pressures and the only observed incidents of tracheal circumferential erythema, the larger ETT30 may be the better choice in most cases where tracheal size is sufficient.

The Educational Role of Autonomy in Medical Training: A Scoping Review.

BACKGROUND: Recent limits imposed on autonomy have raised concern regarding the quality of medical training. The impact of autonomy on medical education has not been comprehensively reviewed. A scoping review was performed to understand the significance of autonomous practice in medical training. METHODS: The MEDLINE and Embase databases were searched for all studies on the role of autonomy in medical training. Articles were included that referenced the medical profession or trainees, and "autonomy," "independence," or "supervision". Data were qualitatively synthesized and analyzed. RESULTS: The search yielded 3649 articles of which 189 were included. Fourteen studies specifically investigated the role of autonomy: 10 surveys on resident perception, and four studies comparing the effect of supervision on learning outcomes. The remaining 175 publications described participant (88) or author (87) opinions regarding the benefits of autonomy as an educational strategy. One quarter (48) of the publications specifically pertained to surgical disciplines, of which one specifically investigated the role of autonomy. Common themes associated autonomy with increased confidence, readiness for independent practice, the development of clinical decision-making skills, and professional identity. CONCLUSIONS: The current literature primarily represents the opinions of medical educators and trainees. A better understanding of the role of autonomy could inform the development of strategies to compensate for the gap left by the current context of decreased autonomy in medical training.

Pathological cyclic strain promotes proliferation of vascular smooth muscle cells via the ACTH/ERK/STAT3 pathway.

Abnormal proliferation of vascular smooth muscle cells (VSMCs) is closely related to hyperplasia in hypertension. Our previous study suggested that adrenocorticotropic hormone (ACTH) is mechano-responsive and may regulate VSMC proliferation. However, the molecular mechanism of VSMC abnormal proliferation induced by conditions of high cyclic strain, especially the role of ACTH in this process, is unclear. Our results revealed that ACTH and its specific receptor melanocortin receptor type 2 (MC2R) were highly expressed in hypertensive rat models. Furthermore, it was demonstrated that the expression of ACTH and MC2R was up-regulated when exposed to high cyclic strain in vitro, accompanied by abnormal proliferation of VSMCs. Next, it was proved that ACTH-dependent cell proliferation was related to the phosphorylation of extracellular regulated protein kinases (ERK) and signal transducer and activator of transcription 3 (STAT3). The study also found that ACTH could promote dimerization and glycosylation of melanocortin 2 receptor accessory protein (MRAP), which had a significant effect on MC2R membrane localization and signal activation. When VSMCs were treated with PD98059, a mitogen-activated protein kinase (MAP kinase) cascade antagonist, it was determined that phosphorylation of STAT3 at Ser727 was dependent on ERK phosphorylation. In summary, these data demonstrated that the abnormal proliferation of VSMCs induced by conditions of high cyclic strain is in part attributed to ACTH and its receptor MC2R. Identifying the mechanism of ACTH-dependent proliferation of VSMCs may help to provide new therapeutic targets for hypertension.

Needle-use declarations at the Olympic Games Rio 2016.

AIM: We report on the results of the 'IOC Needle Policy' applied during the course of the Games of the XXXI Summer Olympiad in Rio de Janeiro, Brazil. The policy was intended to empower physicians to ensure appropriate clinical use of needles within team medical environments, enhance the safety of those responsible for housekeeping services and others in the Olympic environment, and permit documentation of such procedures as an adjunct to the doping control programme. Any needle use required the submission of an 'Injection Declaration Form' to IOC medical officials. METHOD: All 'Injection Declaration Forms' were reviewed and archived. The declarations provided basic information regarding the nature of the needle use and the product(s) involved, the physician, athlete and respective National Olympic Committee (NOC). The details of the declarations were subsequently categorised. RESULTS: A total of 367 declarations were received from physicians representing 49 NOCs. Needle-use declarations were more common in athletics, gymnastics, football and aquatics. A single product was administered in 60% of the cases, and more than one product was administered in 40%. The majority of declarations indicated the use of local anaesthetics, glucocorticoids, non-steroidal anti-inflammatory drugs and analgesics. CONCLUSION: The introduction of a 'Needle Policy' in the Olympic Games setting was intended to minimise the use of needles by non-physicians, promote evidence-based practice and to deter needle-based doping practices. Declarations were received from 49 of 209 NOCs suggesting either that needle use is minimal among certain teams or opportunities remain to enhance compliance with such policies at future games.

Analytical comparability to evaluate impact of manufacturing changes of ARX788, an Anti-HER2 ADC in late-stage clinical development.

ARX788 is an anti-HER2 antibody drug conjugate (ADC) developed using Ambrx proprietary Engineered Precision Biologics technology. The manufacturing process of ARX788 has been optimized during the course of early to late-phase clinical development. A comprehensive evaluation of side-by-side comparability between pre- and post-change process for ARX788 drug substance and drug product from a quality perspective was conducted based on ICH Q5E guidelines consisting of batch release assays, physicochemical and biophysical characterization, biological characterization, and forced degradation studies. All results have substantiated a high degree of similarity between the pre- and post-change ARX788 drug substance batches and drug product lots, demonstrating that the process manufacturing changes did not impact product quality.

Collaborating to improve the global competitiveness of US academic medical centers.

President Obama announced the National Export Initiative in his 2010 State of the Union address and set the ambitious goal of doubling US exports by the end of 2014 to support millions of domestic jobs. Understanding the competitive position of US health care in the global market for international patients, University Health System Consortium (UHC), an alliance of 116 academic medical centers and 272 of their affiliated hospitals, representing 90 percent of the nation's non-profit academic medical centers partnered with Rush University, a private University in Chicago, IL and the International Trade Administration of the US Department of Commerce International Trade Administration (ITA) to participate in the Market Development Cooperator Program. The goal of this private-public partnership is to increase the global competitiveness of the US health care industry, which represents over 16 percent of the GDP, amongst foreign health care providers. This article provides an overview of the US health care market and outlines the aims of the US Cooperative for International Patient Programs, the end result of the partnership between UHC, ITA and Rush University.

The recycling endosome protein Rab25 coordinates collective cell movements in the zebrafish surface epithelium.

In emerging epithelial tissues, cells undergo dramatic rearrangements to promote tissue shape changes. Dividing cells remain interconnected via transient cytokinetic bridges. Bridges are cleaved during abscission and currently, the consequences of disrupting abscission in developing epithelia are not well understood. We show that the Rab GTPase Rab25 localizes near cytokinetic midbodies and likely coordinates abscission through endomembrane trafficking in the epithelium of the zebrafish gastrula during epiboly. In maternal-zygotic Rab25a and Rab25b mutant embryos, morphogenic activity tears open persistent apical cytokinetic bridges that failed to undergo timely abscission. Cytokinesis defects result in anisotropic cell morphologies that are associated with a reduction of contractile actomyosin networks. This slows cell rearrangements and alters the viscoelastic responses of the tissue, all of which likely contribute to delayed epiboly. We present a model in which Rab25 trafficking coordinates cytokinetic bridge abscission and cortical actin density, impacting local cell shape changes and tissue-scale forces.

Control of the activity of CAR-T cells within tumours via focused ultrasound.

Focused ultrasound can deliver energy safely and non-invasively into tissues at depths of centimetres. Here we show that the genetics and cellular functions of chimeric antigen receptor T cells (CAR-T cells) within tumours can be reversibly controlled by the heat generated by short pulses of focused ultrasound via a CAR cassette under the control of a promoter for the heat-shock protein. In mice with subcutaneous tumours, locally injected T cells with the inducible CAR and activated via focused ultrasound guided by magnetic resonance imaging mitigated on-target off-tumour activity and enhanced the suppression of tumour growth, compared with the performance of non-inducible CAR-T cells. Acoustogenetic control of the activation of engineered T cells may facilitate the design of safer cell therapies.

HARMONY: a pragmatic cluster randomised controlled trial of a culturally competent systems intervention to prevent and reduce domestic violence among migrant and refugee families in general practice: study protocol.

INTRODUCTION: Domestic violence and abuse (DVA) is prevalent, harmful and more dangerous among diaspora communities because of the difficulty accessing DVA services, language and migration issues. Consequently, migrant/refugee women are common among primary care populations, but evidence for culturally competent DVA primary care practice is negligible. This pragmatic cluster randomised controlled trial aims to increase DVA identification and referral (primary outcomes) threefold and safety planning (secondary outcome) among diverse women attending intervention vs comparison primary care clinics. Additionally, the study plans to improve recording of DVA, ethnicity, and conduct process and economic evaluations. METHODS AND ANALYSIS: Recruitment of ≤28 primary care clinics in Melbourne, Australia with high migrant/refugee communities. Eligible clinics need ≥1 South Asian general practitioner (GP) and one of two common software programmes to enable aggregated routine data extraction by GrHanite. Intervention staff undertake three DVA training sessions from a GP educator and bilingual DVA advocate/educator. Following training, clinic staff and DVA affected women 18+ will be supported for 12 months by the advocate/educator. Comparison clinics are trained in ethnicity and DVA data entry and offer routine DVA care. Data extraction of DV identification, safety planning and referral from routine GP data in both arms. Adjusted regression analysis by intention-to-treat by staff blinded to arm. Economic evaluation will estimate cost-effectiveness and cost-utility. Process evaluation interviews and analysis with primary care staff and women will be framed by Normalisation Process Theory to maximise understanding of sustainability. Harmony will be the first primary care trial to test a culturally competent model for the care of diverse women experiencing DVA. ETHICS AND DISSEMINATION: Ethical approval from La Trobe University Human Ethics Committee (HEC18413) and dissemination by policy briefs, journal articles and conference and community presentations. TRIAL REGISTRATION NUMBER: ANZCTR- ACTRN12618001845224; Pre-results.

Building a Simple and Versatile Illumination System for Optogenetic Experiments.

Controlling biological processes using light has increased the accuracy and speed with which researchers can manipulate many biological processes. Optical control allows for an unprecedented ability to dissect function and holds the potential for enabling novel genetic therapies. However, optogenetic experiments require adequate light sources with spatial, temporal, or intensity control, often a bottleneck for researchers. Here we detail how to build a low-cost and versatile LED illumination system that is easily customizable for different available optogenetic tools. This system is configurable for manual or computer control with adjustable LED intensity. We provide an illustrated step-by-step guide for building the circuit, making it computer-controlled, and constructing the LEDs. To facilitate the assembly of this device, we also discuss some basic soldering techniques and explain the circuitry used to control the LEDs. Using our open-source user interface, users can automate precise timing and pulsing of light on a personal computer (PC) or an inexpensive tablet. This automation makes the system useful for experiments that use LEDs to control genes, signaling pathways, and other cellular activities that span large time scales. For this protocol, no prior expertise in electronics is required to build all the parts needed or to use the illumination system to perform optogenetic experiments.

Staphylococcus aureus TargetArray: comprehensive differential essential gene expression as a mechanistic tool to profile antibacterials.

The widespread emergence of antibiotic-resistant bacteria and a lack of new pharmaceutical development have catalyzed a need for new and innovative approaches for antibiotic drug discovery. One bottleneck in antibiotic discovery is the lack of a rapid and comprehensive method to identify compound mode of action (MOA). Since a hallmark of antibiotic action is as an inhibitor of essential cellular targets and processes, we identify a set of 308 essential genes in the clinically important pathogen Staphylococcus aureus. A total of 446 strains differentially expressing these genes were constructed in a comprehensive platform of sensitized and resistant strains. A subset of strains allows either target underexpression or target overexpression by heterologous promoter replacements with a suite of tetracycline-regulatable promoters. A further subset of 236 antisense RNA-expressing clones allows knockdown expression of cognate targets. Knockdown expression confers selective antibiotic hypersensitivity, while target overexpression confers resistance. The antisense strains were configured into a TargetArray in which pools of sensitized strains were challenged in fitness tests. A rapid detection method measures strain responses toward antibiotics. The TargetArray antibiotic fitness test results show mechanistically informative biological fingerprints that allow MOA elucidation.

Detecting wetland encroachment and urban agriculture land classification in Uganda using hyper-temporal remote sensing.

Background: Urbanization is an important indicator of economic growth and social change but is associated with environmental degradation, which threatens the sustainable growth of African cities. One of the most vulnerable ecosystems in urban areas are wetlands. In Uganda, wetlands cover an area of 11% of the country's land area. Half of the wetland areas in Ugandan cities have been converted to industrial and residential areas, and urban agriculture. There is limited information on the extent of wetland conversion or utilization for urban agriculture. The objective of this study was to investigate the extent of wetlands lost in two Ugandan cities, Wakiso and Kampala, in the last 30 years. Secondly, we extracted crop agriculture in the wetlands of Kampala and Wakiso from hyper-temporal satellite image analysis in an attempt to produce a spatial detail of wetland encroachment maps of urban agriculture using a reproducible mapmaking method. Methods: Using a field survey and free remote sensing data from Landsat TM 1986 and Landsat ETM 2016 we classified the rate of wetland loss and encroachment between the years 1986 and 2016. We used MODIS NDVI 16-day composites at a 500-meter spatial resolution to broaden the analysis to distinguish distinctive crops and crop mixtures in the encroached wetlands for urban agriculture using the ISODATA clustering algorithm. Results: Over 30 years, 72,828 ha (73%) of the Wakiso-Kampala wetlands have been lost meanwhile agriculture areas have doubled. Of this 16,488 ha (23%) were converted from wetlands. All cultivated agriculture in Kampala was in the wetlands while in Wakiso, 73% of crop agriculture was in the wetlands. The major crops grown in these urban wetlands were banana (20%), sugarcane (22%), maize (17%), Eucalyptus trees (12%), sweet potatoes (10%), while ornamental nurseries, pine trees, vegetables, and passion fruits were each at 5%.

Gender and academic promotion of Canadian general surgeons: a cross-sectional study.

BACKGROUND: Gender disparities in faculty rank have yet to be studied among Canadian physicians. The purpose of this study was to determine whether differences in region, training, research productivity and years in practice explain gender differences in academic promotion among Canadian general surgeons. METHODS: We developed a cross-sectional database of faculty-appointed general surgeons practising in the hospitals affiliated with the 17 universities within the Association of Faculties of Medicine of Canada in 2017 using publicly available directories, university and hospital websites, and direct communication. The data were collected between October and December 2018 and included gender, residency completion year, graduate education, fellowships, number of publications and Scopus h-index; faculty lists and professorship status were verified by program administrators or division heads of their respective divisions. The dependent variable was binary: full professor or not. A combined outcome of associate or full professor was also analyzed. We analyzed all variables in a multivariable logistic regression model. RESULTS: Of the 17 institutions contacted, all but 1 confirmed the faculty lists and professorship status. A total of 405 surgeons were included, of whom 111 (27.4%) were women. Sixty-eight women (61.3%) and 120 men (40.8%) were assistant professors, and 9 women (8.1%) and 75 men (25.5%) were full professors. Although on average women had completed residency more recently than men (15.2 yr v. 19.2 yr, p < 0.001), there was no difference between men and women in the mean number of publications as residents (2.98 v. 2.74, p = 0.7) or per year of practice (3.12 v. 2.09, p = 0.2), number of fellowships pursued (p = 0.7) or graduate education (p = 0.2). In the multivariable model (C-statistic = 0.88), gender remained significantly associated with full professorship (odds ratio 2.79, 95% confidence interval 1.13 to 6.92), along with years in practice (odds ratio 1.61, 95% confidence interval 1.13 to 2.30). INTERPRETATION: After controlling for years in practice, training and research productivity measures, we found that female surgeons with faculty appointments in Canada were less likely than their male counterparts to receive promotion to full professor. Pervasive inequities in systems of promotion must be addressed.

Engineering light-controllable CAR T cells for cancer immunotherapy.

T cells engineered to express chimeric antigen receptors (CARs) can recognize and engage with target cancer cells with redirected specificity for cancer immunotherapy. However, there is a lack of ideal CARs for solid tumor antigens, which may lead to severe adverse effects. Here, we developed a light-inducible nuclear translocation and dimerization (LINTAD) system for gene regulation to control CAR T activation. We first demonstrated light-controllable gene expression and functional modulation in human embryonic kidney 293T and Jurkat T cell lines. We then improved the LINTAD system to achieve optimal efficiency in primary human T cells. The results showed that pulsed light stimulations can activate LINTAD CAR T cells with strong cytotoxicity against target cancer cells, both in vitro and in vivo. Therefore, our LINTAD system can serve as an efficient tool to noninvasively control gene activation and activate inducible CAR T cells for precision cancer immunotherapy.

Decay of Competence with Extended Research Absences During Residency Training: A Scoping Review.

A significant number of residents in postgraduate training programs pursue dedicated research training. Currently, no formal curricula exist to transition residents back into clinical roles following dedicated research leave. This scoping review aims to determine what literature exists on the challenges faced by trainees who interrupt their clinical training for extended periods of time for research leave. The Pubmed and Medline databases were searched for all study designs related to postgraduate trainees taking academic or research leave. A three-step selection process including title, abstract and full-article review was employed to identify articles that mentioned decay of knowledge, skill or competence. A narrative review of the literature was generated to present key themes identified within the studies. The search yielded 174 articles of which five investigated resident skill decay during research leave. The five studies included for analysis were cohort studies that used general surgery residents' self-perception and faculty members' perception of residents' skill decay as a measure. Residents and faculty perceived decay of residents' technical skills, leadership skills and knowledge following dedicated research leave. The greatest decay perceived was in technical skills, specifically with more complex tasks and longer periods of non-use. This review identified that residents and faculty perceive a decay of resident skills following dedicated research training. To provide the necessary support to limit this potential decay, as well as to assist in the transition back into clinical training, the needs of and challenges faced by research residents and postgraduate programs must be better understood.

An AND-Gated Drug and Photoactivatable Cre-loxP System for Spatiotemporal Control in Cell-Based Therapeutics.

While engineered chimeric antigen receptor (CAR) T cells have shown promise in detecting and eradicating cancer cells within patients, it remains difficult to identify a set of truly cancer-specific CAR-targeting cell surface antigens to prevent potentially fatal on-target off-tumor toxicity against other healthy tissues within the body. To help address this issue, we present a novel tamoxifen-gated photoactivatable split-Cre recombinase optogenetic system, called TamPA-Cre, that features high spatiotemporal control to limit CAR T cell activity to the tumor site. We created and optimized a novel genetic AND gate switch by integrating the features of tamoxifen-dependent nuclear localization and blue-light-inducible heterodimerization of Magnet protein domains (nMag, pMag) into split Cre recombinase. By fusing the cytosol-localizing mutant estrogen receptor ligand binding domain (ERT2) to the N-terminal half of split Cre(2-59aa)-nMag, the TamPA-Cre protein ERT2-CreN-nMag is physically separated from its nuclear-localized binding partner, NLS-pMag-CreC(60-343aa). Without tamoxifen to drive nuclear localization of ERT2-CreN-nMag, the typically high background of the photoactivation system was significantly suppressed. Upon blue light stimulation following tamoxifen treatment, the TamPA-Cre system exhibits sensitivity to low intensity, short durations of blue light exposure to induce robust Cre-loxP recombination efficiency. We finally demonstrate that this TamPA-Cre system can be applied to specifically control localized CAR expression and subsequently T cell activation. As such, we posit that CAR T cell activity can be confined to a solid tumor site by applying an external stimulus, with high precision of control in both space and time, such as light.

Sensitive FRET Biosensor Reveals Fyn Kinase Regulation by Submembrane Localization.

Fyn kinase plays crucial roles in hematology and T cell signaling; however, there are currently limited tools to visualize the dynamic Fyn activity in live cells. Here we developed and characterized a highly sensitive Fyn biosensor based on fluorescence resonance energy transfer (FRET) to monitor Fyn kinase activity in live cells. Our results show that Fyn kinase activity can be induced in both mouse embryonic fibroblasts (MEFs) and T cells by ligand engagement. Two different motifs were further introduced to target the biosensor at the cellular membrane microdomains in MEFs, revealing that the Fyn-tagged biosensor had 70% greater response to growth factor stimulation than the Lyn-tagged version. This suggests that the plasma membrane microdomains can be categorized into different functional subdomains. Further experiments show that while the membrane accessibility is necessary for Fyn activation, the localization of Fyn outside of its microdomains causes its hyperactivity, indicating that membrane microdomains provide a suppressive microenvironment for Fyn regulation in MEFs. Interestingly, a relatively high Fyn activity can be observed at perinuclear regions, further supporting the notion that the membrane microenvironment has a significant impact on the local molecular functions. Our work hence highlights a novel Fyn FRET biosensor for live cell imaging and its application in revealing an intricate submembrane regulation of Fyn in live MEFs.

Evaluation of self-injurious behavior, food intake, fecal output, and thermal withdrawal latencies after injection of a high-concentration buprenorphine formulation in rats (Rattus norvegicus).

OBJECTIVE To evaluate effects of high-concentration buprenorphine (HCB) on self-injurious behavior, food intake, fecal output, and thermal withdrawal latencies in healthy rats. ANIMALS 8 Sprague-Dawley rats. PROCEDURES Rats received 4 SC treatments (HCB at 0.075, 0.15, or 0.30 mg/kg [HCB0.075, HCB0.15, and HCB0.30, respectively] or 5% dextrose solution [0.20 mL/kg]) in a randomized, crossover-design study. Self-injurious behavior was assessed for 8 hours after injection. Food intake and fecal output were assessed for predetermined periods before and after treatment and separated into 12-hour light and dark periods for further analysis. Withdrawal latencies were assessed before (time 0) and at predetermined times after injection. Data were compared among treatments and time points. RESULTS Self-injurious behavior was observed up to 8 hours after injection for all HCB, but not dextrose, treatments. Preinjection food intake and fecal output amounts were similar among groups and higher during the dark period than during the light period. Food intake after all HCB treatments was higher during the light period and lower during the dark period, compared with preinjection results for the same treatments and with postinjection results for dextrose administration. Light-period fecal output was lower after HCB0.15 and HCB0.30 administration, compared with preinjection values for the same treatments and postinjection values for dextrose administration. Percentage change in withdrawal latency was significantly higher than that at time 0 (ie, 0%) for only 1 treatment (HCB0.30) at 1 time point (1 hour after injection). CONCLUSIONS AND CLINICAL RELEVANCE Although HCB0.30 produced a degree of thermal hypoalgesia in healthy rats, self-injurious behavior and alterations in food intake and fecal output were detected, potentially affecting clinical utility of the treatment.

Evaluation of self-injurious behavior, thermal sensitivity, food intake, fecal output, and pica after injection of three buprenorphine formulations in rats (Rattus norvegicus).

OBJECTIVE To assess effects of buprenorphine hydrochloride (BH), sustained-release buprenorphine (SRB), and high-concentration buprenorphine (HCB) formulations in healthy rats. ANIMALS 8 Sprague-Dawley rats. PROCEDURES In a crossover-design study, rats received BH (0.05 mg/kg), SRB (1.2 mg/kg), HCB (0.30 mg/kg), or 5% dextrose solution (0.2 mL/kg), SC, once. Self-injurious behavior and thermal sensitivity (hind limb withdrawal latencies) were assessed prior to injection (time 0) and 1, 4, 8, 12, and 24 hours after injection. Food intake, kaolin intake, and fecal output were measured over 12-hour light and dark periods before and after each treatment. Values were compared among treatments and time points. RESULTS Self-injurious behavior was detected with all buprenorphine treatments; scores were greater at all time points during the 12 hours after HCB and 24 hours after SRB administration than at time 0. Percentage change in hind limb withdrawal latencies from time 0 was higher with BH and HCB 1 hour after injection than at other time points. Postinjection light-period food intake was higher (BH and HCB) and dark-period food intake was lower (BH, HCB, and SRB), compared with preinjection values for the same treatments. For SRB, postinjection light-period kaolin intake was greater than the preinjection value, and postinjection light- and dark-period kaolin intake was greater than that for other treatments. CONCLUSIONS AND CLINICAL RELEVANCE Hypoalgesic effects were briefly observed after administration of BH or HCB in healthy rats; adverse effects were detected in some rats with all buprenorphine formulations. Studies comparing effects of BH, SRB, and HCB in rats undergoing surgery or other noxious stimuli are indicated to determine clinical benefits in this species.