Hypothalamic and Pituitary Physiology in Birds and Reptiles.

Across all vertebrates, the anatomy of the hypothalamus and mechanisms underlying its development are highly conserved, whereas the pituitary is highly specialized structurally with considerable differences amongst classes. In birds and reptiles, the hypothalamus controls the pituitary gland through nerve impulses and the secretion of neurohormones, resulting in several hypothalamic-pituitary axes: the hypothalamic-pituitary-thyroid axis, the hypothalamic-pituitary-adrenal axis, and the hypothalamic-pituitary-gonadal axis. This article provides a foundational knowledge on the physiologic function of the hypothalamus and pituitary in birds and reptiles, and their effects on behavior, homeostasis, and disease.

Topical naltrexone potentiates cutaneous wound healing in blackbelt cichlids (Vieja maculicauda).

OBJECTIVE: To evaluate the effects of topical naltrexone on wound healing in freshwater fish. ANIMALS: 25 blackbelt cichlids (Vieja maculicauda). METHODS: A randomized, controlled, experimental trial was performed, with each individual serving as its own control. Bilateral 6-mm periepaxial cutaneous wounds were created in the body-wall skin of each fish under anesthesia. Three treatment groups were as follows: topical 0.04% naltrexone in administration vehicle (iLEX ointment; iLEX Health Products) at day 0 only (n = 10), topical 0.04% naltrexone in iLEX every 72 to 96 hours (n = 10), or iLEX only every 72 to 96 hours (n = 5) for 10 total treatments. The contralateral wound was left untreated as a control. Fish were maintained in a common enclosure at 24.7 to 25.4 °C for 35 days. Macroscopic wound assessment and image collection were performed every 72 to 96 hours. On day 35, fish were humanely euthanized, and skin samples were collected for histopathology. RESULTS: Time to complete visual resolution of wound healing was faster (P = .002) in wounds treated every 72 to 96 hours with topical 0.04% naltrexone in iLEX (day 19.4) compared to untreated wounds (day 23.3). An interaction between treatment and day was observed (P = .002), with fish treated with 0.04% naltrexone in iLEX every 72 to 96 hours having reduced (P < .05) wound area compared to both controls and fish treated with topical 0.04% naltrexone in iLEX once. No significant differences were noted in histologic sections of wound sites examined at day 35. CLINICAL RELEVANCE: Fish improved earlier postsurgery and time to complete wound resolution was faster in wounds treated with topical 0.04% naltrexone in iLEX every 72 to 96 hours.

Nannizziopsis guarroi has prolonged environmental persistence on clinically relevant substrates.

OBJECTIVE: To determine the environmental persistence of Nannizziopsis guarroi on clinically relevant solid and aqueous substrates. SAMPLE: 2 molecularly confirmed isolates of N guarroi obtained from clinical cases of dermatomycosis in bearded dragons (Pogona vitticeps). PROCEDURES: 3 concentrations (1 McFarland, 1:10 McFarland, and 1:100 McFarland) of fungal suspension were exposed to 7 sterilized solid substrates (fabric aquarium liner, wood mulch, sand, hard plastic, glass, cotton, and stainless steel) and 2 sterilized aqueous substrates (distilled water, saline solution [0.9% NaCl]). Biological replicates were performed for the contamination of the solid substrates. On days 1, 3, and 14 after contamination, the substrates were sampled for fungal culture with technical repeat. Fungal cultures were incubated at room temperature for 10 days and then evaluated for fungal growth. RESULTS: Data from wood mulch were not evaluated because of plate contamination. Overall, the ability to culture N guarroi from solid substrates was isolate, time, and fungal concentration dependent. Viable fungus was isolated from fabric aquarium liner and glass on day 1 and days 1 and 3, respectively. N guarroi was cultured from all other solid substrates at day 14 from at least 1 isolate and/or fungal concentration. Viable N guarroi was isolated from both aqueous substrates at day 14, regardless of isolate or fungal concentration. CLINICAL RELEVANCE: The environmental persistence of N guarroi should be considered when treating lizards infected with this fungus. Fomites may contribute to the contagious nature of this pathogen and environmental disinfection should be performed to reduce transmission.

CAUSES OF MORTALITY AND COMORBIDITIES IN CAIMAN LIZARDS (DRACAENA GUIANENSIS) AT SIX ZOOLOGICAL INSTITUTIONS.

An understanding of the main causes of mortality in caiman lizards (Dracaena guianensis) under managed care is imperative to promote optimal husbandry, health, and welfare. A retrospective review of morbidity and mortality in caiman lizards from North American zoological institutions between 2005 and 2020 was conducted. Postmortem data, including gross necropsy and histopathology findings, were available for 32 caiman lizards (n = 12 subadults, n = 20 adults) from six zoological institutions. Necropsy reports were evaluated to collect general demographic data, categorize cause of death (accident/trauma, congenital/genetic, degenerative/geriatric, infectious, deposition disease, neoplastic, unknown, and multifactorial), and assess common comorbidities. Infectious disease was the most common cause of mortality in adult lizards (8/20; 40%) with amoebiasis and bacterial etiologies being overrepresented. Demise due to traumatic/accidental injury was the second most common cause of death in adult lizards (3/20;15%) and included blunt force trauma or suspected drowning. Infectious disease (4/12; 33.3%) and trauma/accidental injury (4/12; 33.3%) were also the most common causes of death in subadults. The most common comorbidities or other incidental findings identified during necropsy included trematode parasitism (15/32; 46.9%), arteriosclerosis (11/32; 34.4%), and adrenocortical hyperplasia (6/32; 18.8%). This retrospective review suggests that management practices to prevent and control infectious diseases and mitigate traumatic injury play a pivotal role in the long-term care and survival of caiman lizards in managed care.

Bioencapsulation is a feasible method of terbinafine administration in Emydomyces testavorans-infected western pond turtles (Actinemys marmorata).

OBJECTIVE: To evaluate the pharmacokinetics of terbinafine administered to western pond turtles (Actinemys marmorata) via oral gavage and bioencapsulated in earthworms. ANIMALS: 7 western pond turtles. PROCEDURES: A randomized complete crossover single-dose pharmacokinetic study was performed. Compounded terbinafine (25 mg/mL; 30 mg/kg) was administered through oral gavage (OG) directly into the stomach or bioencapsulated (BEC) into an earthworm vehicle. Blood (0.2 mL) was drawn from the jugular vein at 0, 0.5, 1, 2, 4, 8, 12, 24, 48, 72, and 120 hours after administration. Plasma terbinafine levels were measured using high-performance liquid chromatography. RESULTS: Peak plasma terbinafine concentrations of 786.9 ± 911 ng/mL and 1,022.2 ± 911 were measured at 1.8 ± 2.8 and 14.1 ± 12.3 hours after OG and BEC administration, respectively. There was a significant (P = .031) increase in area under the curve with BEC compared to OG. Using steady-state predictions, with once-daily terbinafine administration, 3/7 and 7/7 turtles had plasma concentrations persistently greater than the minimum inhibitory concentration (MIC) for Emydomyces testavorans for the OG and BEC administration routes of administration, respectively. With administration every 48 hours, 3/7 turtles for the OG phase and 6/7 turtles for the BEC phase had concentrations greater than the E. testavorans MIC throughout the entire dosing interval. CLINICAL RELEVANCE: Administration of terbinafine (30 mg/kg) every 24 or 48 hours via earthworm bioencapsulation in western pond turtles may be appropriate for the treatment of shell lesions caused by E. testavorans. Clinical studies are needed to assess the efficacy of treatment.

Clinicopathologic findings and urolith composition for green iguanas (Iguana iguana) with urolithiasis: 21 cases and 132 stones (1996-2020).

OBJECTIVE: To document the clinical signs, diagnosis, and treatment of urolithiasis in green iguanas (Iguana iguana) and to report on the composition of uroliths from green iguanas submitted to the Minnesota Urolith Center for analysis. ANIMALS: 21 green iguanas with urolithiasis. PROCEDURES: Medical record databases of multiple veterinary teaching hospitals were searched from 1996 through 2020. Emails were sent to all facilities that submitted a urolith from a green iguana to the Minnesota Urolith Center from 1996 through 2020. Signalment; presenting complaint; physical examination findings; hematologic, biochemical, and diagnostic imaging findings; treatment; necropsy results; and survival times were described for each patient. RESULTS: Iguanas most commonly presented with nonspecific clinical signs, but 9 of the 21 iguanas had clinical signs associated with the urogenital tract. Twelve iguanas had a palpable mass in the caudal coelom. All uroliths were visible on radiographs. Surgery was performed on 15 iguanas; 3 died secondary to intra- or postoperative complications. Iguanas that underwent surgery had a median survival time of 39 months. Necropsy was performed on 5 iguanas, and urolithiasis contributed to the decision to euthanize or was the cause of death for 4. Uroliths from 132 iguanas were analyzed, and all were composed of 100% uric acid salts. CLINICAL RELEVANCE: Green iguanas with urolithiasis may not have clinical signs or physical examination findings associated with the urinary system, and hematologic and biochemical abnormalities are nonspecific. Green iguanas should be routinely examined for uroliths, and surgical treatment should be pursued.

DETECTION OF VECTOR-BORNE INFECTIONS IN LIONS AND TIGERS AT TWO ZOOS IN TENNESSEE AND OKLAHOMA, USA.

Protozoal and bacterial vector-borne infections are frequently diagnosed in domestic felids. However, with the exception of Mycoplasma haemofelis and Cytauxzoon felis, their occurrence in managed nondomestic felids housed in the United States is largely unknown. Following a case in February 2020 of fulminant cytauxzoonosis in an African lion (Panthera leo), EDTA-whole blood samples were collected opportunistically from February 2020 through June 2020 from 34 adult tigers (Panthera tigris) and eight adult African lions from the same sanctuary in eastern Tennessee as well as 14 adult tigers from a zoo in southern Oklahoma. Samples were analyzed for Cytauxzoon felis, Bartonella spp., hemotropic Mycoplasma, Rickettsia spp., Anaplasma spp., Ehrlichia spp., Babesia spp., and Hepatozoon spp. DNA by PCR amplification. All animals were asymptomatic at the time of collection. None of the Oklahoma animals were positive for vector-borne organisms, but these pathogens were detected in tigers at the Tennessee facility, including Cytauxzoon felis (11.8%), "Candidatus Mycoplasma haemominutum" (5.9%), and Ehrlichia ewingii (2.9%). During the study period, two animals developed clinical signs of cytauxzoonosis and were assessed for vector-borne infections as part of their diagnostic evaluation. This study documents the presence of tick-borne diseases in managed nondomestic felids in the southeastern United States and underscores that ectoparasite control measures should be practiced to minimize exposure of carnivores in managed care.

Comparative nutrient analysis of four species of cockroaches used as food for insectivores by life stage, species, and sex.

A variety of insects are fed to insectivorous animals; however, nutritional analyses are often limited to adult life stages. Four species of nymph and adult female and male cockroaches (Blaberus giganteus, Blaptica dubia, Blatta lateralis, and Gromphadorhina portentosa) were analyzed for moisture, crude protein (CP), acid detergent fiber (ADF), fat, ash, and mineral content. The small sample size of this study precluded statistical analyses, however comparatively, CP in adult B. lateralis and B. dubia was greater than the CP in nymphs of the same species. Adult and nymph B. dubia had the greatest CP (96.6% and 65.3%, respectively) compared to the other three species. Inversely, fat content in adult B. lateralis and B. dubia was lower than that of nymphs of the same species. All adults contained similar levels of ADF, yet adult B. giganteus had greater ADF than nymphs; conversely, B. lateralis and B. dubia adults had less ADF than nymphs. There were differences noted in mineral parameters among the four species and life stages. Adult B. giganteus had less Ca than G. portentosa, and the lowest Ca content of the four species of nymphs and adults analyzed. This study underscores the differences in nutrient content with respect to life stage and species in previously understudied cockroaches to improve nutrient intake in captive insectivores.

Hematology of the keeled box turtle (Cuora mouhotii).

A healthy adult, intact female keeled box turtle (Cuora mouhotii) was found to have a marked heterophilic leukocytosis using normal hematologic parameters established for the eastern box turtle (Terrapene carolina carolina), a related chelonian species. This animal was monitored with serial complete blood counts (CBCs) over the next 15 years despite remaining asymptomatic for an infectious condition. Retrospective CBC data were compiled from 38 presumably healthy keeled box turtles to establish hematologic values for comparison in this species. Using this species-specific data, over the 15-year period, the female keeled box turtle had two times where the white blood cell (WBC) count was greater than 2 standard deviations (SD) above the mean, six times where the WBC count was greater than 1 SD above the mean, six times where the PCV was greater than 2 SD above the mean, and eight times where the PCV was greater than 1 SD above the mean. Infection and inflammation are the most common causes of leukocytosis in reptiles; however, given the clinical presentation of this patient, it was postulated that these clinicopathologic changes could be secondary to a stress response. Establishing reference intervals and understanding how stress impacts CBC parameters are important for evaluating the health status of keeled box turtles kept in captivity and for assessing the effects of environmental changes on the health status of wild populations of this endangered chelonian species.

Venous hematology, biochemistry, and blood gas analysis of free-ranging Eastern Copperheads (Agkistrodon contortrix) and Eastern Ratsnakes (Pantherophis alleghaniensis).

Hematology, plasma biochemistry, and blood gas analysis were performed on venous samples obtained from free-ranging Eastern Copperheads (Agkistrodon contortrix) and Eastern Ratsnakes (Pantherophis alleghaniensis) in central North Carolina during a mark-recapture study conducted from April to October 2015 at the North Carolina Zoo. Blood samples were collected from 31 (15 male and 16 female) free-ranging copperheads and 34 (20 male and 14 female) free-ranging ratsnakes at the beginning and end of restraint. Restraint was performed for morphometric measurements, sex determination, and identification via placement of intracelomic passive integrated transponder (PIT) tags and marking of ventral scutes with a handheld electrocautery unit. Blood gas analytes were measured at the beginning of restraint and compared to analytes measured at the end to evaluate for changes secondary to handling. Total restraint time prior to the first blood sampling was 1.4 ± 0.4 mins (mean ± SD) and 1.0 ± 0.2 mins (mean ± SD) and restraint time prior to second blood sampling was 12.5 ± 2.4 mins (mean ± SD) and 13.5 ± 3.4 mins (mean ± SD) for copperheads and ratsnakes, respectively. Blood lactate concentrations at the beginning of restraint were similar for both species. Lactate concentrations increased significantly and pH decreased significantly for both species at the end of restraint when compared to the beginning of restraint. Furthermore, lactate concentrations at the end of restraint were significantly elevated in ratsnakes compared to copperheads. This study provides guidelines for interpretation of venous hematology, plasma biochemistry, and blood gas values for free-ranging copperheads and ratsnakes in central North Carolina and demonstrates the physiological response to venous blood gas analytes secondary to capture and restraint.

Perceptions and attitudes of Small Animal Internal Medicine specialists toward the publication requirement for board certification.

BACKGROUND: The publication requirement for board certification in Small Animal Internal Medicine (SAIM) by the ACVIM is controversial. OBJECTIVES: Directly and indirectly evaluate the perceptions SAIM Diplomates have on the publication requirement. A secondary objective was to compare the frequency with which publications submitted for credentialing purposes (CredPubs) were cited compared to control articles. SUBJECTS: One thousand two hundred forty-one SAIM Diplomates were sent an electronic survey. METHODS: A electronic survey was sent to all SAIM Diplomates. Practice websites were evaluated for reference to publication or research. An electronic database was searched to identify the number of times a subset of CredPubs were cited was compared to control articles. RESULTS: Five hundred six individuals responded. The majority of respondents (n = 428, 85.25%) stated the requirement should be retained either with no changes (n = 186, 37.05%) or with clarifications or modifications (n = 242, 48.21%). A minority of respondents (n = 74, 14.7%) felt it should be eliminated. "Understanding the scientific process" was the most commonly selected reason (n = 467, 92.48%) for the publication requirement. All websites that mentioned research or publication did so using a positive sentiment. With regard to relative citation rates; 17% of CredPubs were in the lower quartile, 59.1% of CredPubs were in the interquartile range, and 23.5% were in the upper quartile compared to control articles. CONCLUSIONS AND CLINICAL IMPORTANCE: A majority of SAIM Diplomates favored the retention of the publication requirement in some form. CredPubs were cited at rates similar to control articles.

HISTOPLASMOSIS IN NONDOMESTIC FELIDS: A REVIEW OF SIX CASES.

One adult leopard (Panthera pardus) and five adult tigers (Panthera tigris) presented with a range of nonspecific clinical signs, including lethargy (6/6), mobility deficits (4/6), and hyporexia (3/6). Hematology and biochemistry revealed a hyperproteinemia characterized by hyperglobulinemia (4/6), hepatocellular enzyme activity increases (3/6), azotemia (3/6), leukocytosis (2/6), hyperbilirubinemia (2/6), or a combination of conditions. Further diagnostics and management varied with the presenting signs and clinicopathological findings, including supportive care, diagnostic imaging, and blastomyces urine antigen analyses. Two animals died, and four were euthanatized. Postmortem findings included granulomatous pneumonia (6/6), fibrinous pleural effusion (3/ 6), pericardial effusion (2/6), and diffuse icterus (1/6). Histopathology revealed round to oval structures with a thin clear wall and purple inclusions within cells of the mononuclear phagocyte system, consistent with Histoplasma capsulatum, in each animal. Disseminated histoplasmosis was found in five cases, with organisms present in the lung (5/5), liver (3/5), lymph nodes (3/5), spleen (2/5), bone marrow (2/5), thyroid (1/5), tongue (1/ 5), kidney (1/5), or a combination of organs. One tiger was found to have pulmonary histoplasmosis without evidence of disseminated infection. On the basis of clinical and pathological findings, histoplasmosis was diagnosed. This case series illustrates the difficulties in antemortem diagnosis of histoplasmosis on the basis of complete blood count, serum biochemistry profile, and antigen testing and underscores that histoplasmosis should be considered a differential diagnosis in any felid presenting with nonspecific clinical signs in endemic areas.

Bilateral Phacoemulsification in an African Elephant (Loxodonta africana).

A 37-year-old bull African elephant (Loxodonta africana) at the North Carolina Zoo (NCZ) was diagnosed with bilateral cataracts leading to behavioral changes and significant weight loss secondary to functional blindness. On initial examination, a weight loss of 234 kg, a mature cataract in the right eye, and a focal cataract in the left eye were diagnosed. Ultrasound and electroretinography (ERG) indicated normal retinal attachment and both eyes were viable candidates for surgery. After careful planning and behavioral training, the left cataract was surgically removed via phacoemulsification and irrigation/aspiration. The right eye subsequently developed a ventral lens subluxation, and phacoemulsification and irrigation/aspiration were performed six months after the first procedure. Four years after surgery, menace response, palpebral reflex, dazzle reflex, and pupillary light reflexes were present in both eyes. Body weight was 5,515 kg, 88kg more than at the time of the second surgery. This is the first published report of an African bull elephant undergoing bilateral cataract removal using phacoemulsification and irrigation/aspiration. The lack of significant postoperative inflammation and uneventful recovery of the elephant suggests that this surgical procedure along with proper preoperative planning and postoperative medical management can be a safe and effective treatment option for elephants with cataracts.

TISSUE ENZYME ACTIVITIES IN FREE-LIVING EASTERN BOX TURTLES (TERRAPENE CAROLINA CAROLINA).

Plasma biochemical enzymes are commonly assayed as part of a diagnostic evaluation for zoological species, but their interpretation is complicated by a lack of knowledge about tissue of origin in many reptiles. This study evaluated tissue specificity of six biochemical enzymes (alanine aminotransferase [ALT], aspartate aminotransferase [AST], alkaline phosphatase [ALP], creatine kinase [CK], gamma-glutamyl transferase [GGT], and glutamate dehydrogenase [GLDH]) in 10 tissues (skeletal muscle, cardiac muscle, lung, liver, gallbladder, pancreas, gastrointestinal tract, kidney, spleen, and reproductive tract) from 10 free-living eastern box turtles (Terrapene carolina carolina). CK activity was highest in skeletal muscle, cardiac muscle, and gastrointestinal tract; GLDH and ALT activities were highest in liver, kidney, and gallbladder; ALP and GGT activities were elevated in kidney and gastrointestinal tract; and AST was relatively nonspecific, with significantly higher activity in the cardiac muscle, liver, kidney, skeletal muscle, and gallbladder compared to other tissues (P < 0.05). These results serve as a first step toward improving clinical interpretation of plasma biochemistry panels in box turtles.

Pharmacokinetics of ketorolac in wild Eastern box turtles (Terrapene carolina carolina) after single intramuscular administration.

Ketorolac is a nonsteroidal anti-inflammatory drug that possesses potent analgesic activity comparable to morphine. The opioid shortage in the United States has led to an unreliable supply of opioids for use in rehabilitation facilities, thus underscoring the need for research on the safe and effective use of nonopioid alternatives. The goal of this study was to determine the pharmacokinetics of ketorolac after a single 0.25 mg/kg intramuscular injection administered to injured Eastern box turtles (Terrapene carolina carolina). A sparse blood sampling protocol was used to collect samples from 32 wild turtles that presented to the Turtle Rescue Team at North Carolina State University for traumatic injuries. Blood was collected from 0 to 24 hr after injection and analyzed via high-pressure liquid chromatography (HPLC). A nonlinear mixed-effects (NLME) model was fitted to the data to obtain typical values for population parameters. Using this approach, we identified a long half-life (T1/2 ) of 9.78 hr and a volume of distribution (Vss ) of 0.26 L/kg. We have concluded that this long T1/2 for a dose of 0.25 mg/kg ketorolac-injected IM provides plasma levels above a previously published target level for 24-hour analgesia to allow for once daily dosing.

EVALUATION OF ACUPUNCTURE POINTS GOVERNING VESSELS 1 AND 26 ON ANESTHETIC RECOVERY OF EASTERN BOX TURTLES ( TERRAPENE CAROLINA CAROLINA).

Intramuscular administration of anesthetic agents in chelonians may result in a prolonged (≥1 hr) return of spontaneous movement and breathing, which increases the probability for peri- and postoperative complications. The acupuncture point governing vessel (GV)-26 has been demonstrated to reduce anesthetic recovery times from inhalant anesthesia in other species. In this study, 30 eastern box turtles (EBT; Terrapene carolina carolina), presented to the Turtle Rescue Team at North Carolina State University's College of Veterinary Medicine for treatment of aural abscess, were divided into four groups: control (no treatment); GV-26 acupuncture; GV-1 and GV-26 acupuncture; or GV-1 and GV-26 electroacupuncture. Turtles receiving either GV-1 and GV-26 acupuncture or GV-1 and GV-26 electroacupuncture had a significantly reduced time to return of voluntary movement ( P = 0.012 and P = 0.006, respectively), a significantly reduced time to response of limb extension ( P = 0.03 and P < 0.001, respectively), and a significantly reduced time to anesthetic recovery ( P < 0.05 and P < 0.01, respectively). Therefore, the use of either GV-1 and GV-26 acupuncture or GV-1 and GV-26 electroacupuncture produces significant reductions in anesthetic recovery time in EBTs that have received injectable anesthetics.

ASSESSMENT OF A VISUAL SCORING SYSTEM FOR IDENTIFYING AND QUANTIFYING ANEMIA IN MALE EASTERN BOX TURTLES ( TERRAPENE CAROLINA CAROLINA).

The North Carolina State University College of Veterinary Medicine Turtle Rescue Team (TRT) regularly admits wild eastern box turtles (EBT) ( Terrapene carolina carolina) for treatment and rehabilitation. Adult males of this species generally have an impressive red coloration of the iris, a feature commonly used to differentiate them from their brown-eyed female conspecifics. Male EBTs that present often display marked pallor of the eyes, which has accompanied clinical anemia. The aim of this study was to examine the relationship between eye color and packed cell volume (PCV) in adult male EBTs, and to assess the accuracy of using eye color to predict PCV. Eye-color scoring cards were created using Adobe Creative Cloud Photoshop®. Each card was composed of blocks displaying progressively lighter tints of a red hue, with a number (score) assigned to each block. Five-block, six-block, and nine-block scoring cards were prepared, with lower numbers (scores) corresponding to lighter hues. To determine the variation in subjective color scores assigned by different human observers, 85 individuals were asked to score EBT eye color in three animals using each of the three scoring cards. Eye color of adult male EBTs that presented to the TRT ( n = 18) and those housed at the North Carolina Museum of Natural Sciences ( n = 6) were scored using each of the three cards, immediately preceding venipuncture of the occipital sinus for determination of PCV. All animals were scored by at least two individuals. Turtles with low scores (pale eyes) using all three scoring cards consistently had lower PCVs. The five- and six-block scorecards had a positive predictive value (PPV) of 100% while the nine-block score card had a PPV of 71.4%. This specific and noninvasive method for estimating PCV of male EBTs is clinically desirable in both rehabilitation and hospital settings.

Pharmacokinetics and pharmacodynamic effects in koi carp (Cyprinus carpio) following immersion in propofol.

OBJECTIVE: To test the hypothesis that plasma propofol concentration (PPC) is associated with anesthetic effect in koi carp administered propofol by immersion. STUDY DESIGN: Prospective study. ANIMALS: Twenty mature koi carp (mean ± standard deviation, 409.4 ± 83.7 g). METHODS: Fish were immersed in propofol (5 mg L-1). Physiological variables and induction and recovery times were recorded. In phase I, blood was sampled for PPC immediately following induction and at recovery. In phase II, following induction, fish were maintained with propofol (4 mg L-1) via a recirculating system for 20 minutes. Following established induction, blood was sampled at 1, 10 and 20 minutes. In phase III (n = 19), fish were anesthetized as in phase II with blood sampled nine times in a sparse sampling strategy. Simultaneously, a pharmacodynamics rubric was used to evaluate anesthetic depth. PPC was determined using high performance liquid chromatography with fluorescence detection. Following evaluation of normality, data were analyzed using paired t test or Spearman correlation test (significance was set at p < 0.05). RESULTS: In phase I, mean PPCs at induction (20.12 µg mL-1) and recovery (11.62 µg mL-1) were different (p < 0.001). In phase II, only mean PPCs at induction (17.92 µg mL-1) and 10 minutes (21.50 µg mL-1) were different (p = 0.013). In phase III, a correlation between PPCs and the pharmacodynamic rubric scores was found (p < 0.001, r = -0.93). There was no correlation between PPCs and recovery time (p = 0.057, r = 0.433). A two-compartment open model was chosen for the pharmacokinetic model. Absorption rate constant, elimination rate constant and intercompartmental rate constant were 0.48, 0.006 and 0.02 minute-1, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Measurable PPCs were achieved in koi carp anesthetized with propofol by immersion. Anesthetic depth of fish was negatively correlated with PPCs, but recovery time was not.

Forelimb muscle plasticity following unilateral cervical spinal cord injury.

INTRODUCTION: Motor dysfunction and muscle atrophy are well documented in the lower extremity after spinal cord injury. However, the extent and time course of myoplastic changes in forelimb musculature is not clear. METHODS: Forelimb muscle morphology and fiber type were evaluated after high cervical hemilesion injury in rats. RESULTS: There was significant atrophy of the ipsilateral extensor carpi radialis longus (ECRL) muscle at 2 weeks postinjury, which was subsequently reversed at 8 weeks postinjury. The triceps muscle showed minimal evidence of atrophy after spinal injury. No significant changes in fiber type were observed. CONCLUSIONS: These findings indicate a robust capacity for spontaneous myoplasticity after C2 hemisection injury but highlight differential capacity for plasticity within the forelimb muscles.

Stimulation of Respiratory Motor Output and Ventilation in a Murine Model of Pompe Disease by Ampakines.

Pompe disease results from a mutation in the acid α-glucosidase gene leading to lysosomal glycogen accumulation. Respiratory insufficiency is common, and the current U.S. Food and Drug Administration-approved treatment, enzyme replacement, has limited effectiveness. Ampakines are drugs that enhance α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor responses and can increase respiratory motor drive. Recent work indicates that respiratory motor drive can be blunted in Pompe disease, and thus pharmacologic stimulation of breathing may be beneficial. Using a murine Pompe model with the most severe clinical genotype (the Gaa(-/-) mouse), our primary objective was to test the hypothesis that ampakines can stimulate respiratory motor output and increase ventilation. Our second objective was to confirm that neuropathology was present in Pompe mouse medullary respiratory control neurons. The impact of ampakine CX717 on breathing was determined via phrenic and hypoglossal nerve recordings in anesthetized mice and whole-body plethysmography in unanesthetized mice. The medulla was examined using standard histological methods coupled with immunochemical markers of respiratory control neurons. Ampakine CX717 robustly increased phrenic and hypoglossal inspiratory bursting and reduced respiratory cycle variability in anesthetized Pompe mice, and it increased inspiratory tidal volume in unanesthetized Pompe mice. CX717 did not significantly alter these variables in wild-type mice. Medullary respiratory neurons showed extensive histopathology in Pompe mice. Ampakines stimulate respiratory neuromotor output and ventilation in Pompe mice, and therefore they have potential as an adjunctive therapy in Pompe disease.