Comparison of pharmacodynamics between insulin glargine 100 U/mL and insulin glargine 300 U/mL in healthy cats.

Insulin glargine (IGla) is a synthetic human-recombinant insulin analog that is used routinely in people as a q24h basal insulin. The 300 U/mL (U300) formulation of IGla is associated with longer duration of action and less within-day variability, making it a better basal insulin compared with the 100 U/mL (U100) formulation. We hypothesized that in healthy cats, IGlaU300 has a flatter time-action profile and longer duration of action compared with IGlaU100. Seven healthy neutered male, purpose-bred cats were studied in a randomized, crossover design. Pharmacodynamics of IGlaU100 and IGlaU300 (0.8 U/kg, subcutaneous) were determined by the isoglycemic clamp method. The time-action profile of IGlaU300 was flatter compared with IGlaU100 as demonstrated by lower peak (5.6 ± 1.1 mg/kg/min vs 8.3 ± 1.9 mg/kg/min, respectively; P = 0.04) with no difference in total metabolic effect (ME; P = 0.7) or duration of action (16.8 h ± 4.7 h vs 13.4 h ± 2.6 h; P = 0.2). The greater fraction of ME in the 12- to 24-h period postinjection (35 ± 23% vs 7 ± 8% respectively; P = 0.048) and lower intraday GIR% variability (7.8 ± 3.7% vs 17.4 ± 8.2% respectively; P = 0.03) supports a flatter time-action profile of IGlaU300. There were no differences in onset and end of the action. In summary, although both formulations have a similar duration of action that is well below 24 h, the ME of IGlaU300 is more evenly distributed over a 24 h period in healthy cats, making it a better candidate for once-daily injection in diabetics compared with IGlaU100.

Dental Pathology of the Hoary Marmot (Marmota caligata), Groundhog (Marmota monax) and Alaska Marmot (Marmota broweri).

Museum specimens (maxillae and mandibles) of the three marmot species occurring in Alaska (Marmota caligata [n = 108 specimens], Marmota monax [n = 30] and Marmota broweri [n = 24]) were examined macroscopically according to predefined criteria. There were 71 specimens (43.8%) from female animals, 69 (42.6%) from male animals and 22 (13.6%) from animals of unknown sex. The ages of animals ranged from neonatal to adult, with 121 young adults (74.4%) and 41 adults (25.3%) included, and 168 excluded from study due to neonatal/juvenile age or incompleteness of specimens (missing part of the dentition). None of the teeth were missing, so 3,564 teeth were available for examination. All teeth were normal in morphology and none was affected by enamel hypoplasia. Two specimens displayed two supernumerary teeth each. One-third of specimens displayed attrition/abrasion and in 38.9% of these the change involved all premolar and molar teeth. The proportion of adult specimens affected by attrition/abrasion was three times as high as young adult specimens. Dental fractures were rare, noted in only two specimens, affecting 0.08% of teeth (n = 3). Periapical disease was also rare, with a striking lesion in one young adult female specimen. Some degree of periodontitis was seen in 26 specimens (16.1%), affecting 4.6% of premolar and molar teeth. The proportion of adults with periodontitis was over three times as high as that for young adults. Five specimens displayed mild malocclusion. Although the clinical significance of dental pathology in the marmot species of Alaska remains elusive, the occurrence and severity of some dental lesions may play an important role in their morbidity and mortality.

Dental and Temporomandibular Joint Pathology of the Polar Bear (Ursus maritimus).

Museum specimens (maxillae and/or mandibles) from 317 polar bears (Ursus maritimus) were examined macroscopically according to predefined criteria and 249 specimens were included in this study. The specimens were acquired between 1906 and 2011. There were 126 specimens (50.6%) from male animals, 93 (37.3%) from female animals and 30 (12.1%) from animals of unknown sex. The ages of the animals ranged from neonate to adult, with 125 adults (50.2%) and 124 young adults (49.8%) included and neonates/juveniles excluded from the study. The number of teeth available for examination was 7,638 (73.5%); 12.3% of teeth were absent artefactually, 0.8% were deemed absent due to acquired tooth loss and 13.4% were absent congenitally. With respect to tooth morphology, 20 teeth (0.26% of available teeth) in 18 specimens (7.2% of available specimens) were small vestigial structures with crowns that were flush with the level of surrounding alveolar bone. One supernumerary tooth and one tooth with enamel hypoplasia were encountered. Persistent deciduous teeth and teeth with an aberrant number of roots were not found. Relatively few teeth (3.7%) displayed attrition/abrasion, 90% of which were the maxillary and mandibular incisor teeth, in 41 polar bears (16.5%). Nearly twice as many adult specimens exhibited attrition/abrasion as those from young adults; significantly more males were affected than females. Dental fractures were noted in 52 polar bears, affecting 20.9% of specimens and 1.3% of the total number of teeth present. More adult polar bears had dental fractures than young adults. There were 21 specimens (8.4%) that displayed overt periapical disease, affecting a total of 24 dental alveoli (0.23%). Some degree of periodontitis was seen in 199 specimens (79.9%); however, only 12.6% of dental alveoli had bony changes indicative of periodontitis. Lesions consistent with temporomandibular joint osteoarthritis (TMJ-OA) were found in 23 specimens (9.2%). TMJ-OA was significantly more common in adults than in young adults and in males than in females. Although the clinical significance of dental and TMJ pathology in the polar bear remains elusive, the occurrence and severity of these lesions may play an important role in the morbidity and mortality of this species.

Dental and Temporomandibular Joint Pathology of the Walrus (Odobenus rosmarus).

Maxillae and/or mandibles from 76 walruses (Odobenus rosmarus) were examined macroscopically according to predefined criteria. The museum specimens were acquired between 1932 and 2014. Forty-five specimens (59.2%) were from male animals, 29 (38.2%) from female animals and two (2.6%) from animals of unknown sex, with 58 adults (76.3%) and 18 young adults (23.7%) included in this study. The number of teeth available for examination was 830 (33.6%); 18.5% of teeth were absent artefactually, 3.3% were deemed to be absent due to acquired tooth loss and 44.5% were absent congenitally. The theoretical complete dental formula was confirmed to be I 3/3, C 1/1, P 4/3, M 2/2, while the most probable dental formula is I 1/0, C 1/1, P 3/3, M 0/0; none of the specimens in this study possessed a full complement of theoretically possible teeth. The majority of teeth were normal in morphology; only five teeth (0.6% of available teeth) were malformed. Only one tooth had an aberrant number of roots and only one supernumerary tooth was encountered. No persistent deciduous teeth were found in any of the young adult or adult specimens, nor were any specimens affected by enamel hypoplasia. The majority of teeth (85.5%) displayed attrition/abrasion. Of the adult and young adult specimens, 90.8% showed some degree of attrition/abrasion on at least one tooth. Tooth fractures were noted in eight walruses, affecting 10.5% of specimens and 1.3% of the total number of teeth, nearly three-quarters of which were maxillary canine teeth (tusks). Three specimens (3.9%), all adult males, displayed overt periapical disease. The majority (99.2%) of dental alveoli did not have bony changes indicative of periodontitis, with only five specimens (6.6%) affected by periodontitis. Lesions consistent with temporomandibular joint osteoarthritis (TMJ-OA) were found in 46 specimens (60.5%) and TMJ-OA was significantly more common in adults than young adults and males than females. Although the clinical significance of dental and TMJ pathology in the walrus remains unknown, the occurrence and severity of these lesions may play an important role in the morbidity and mortality of this species.

Characterization of the temporomandibular joint of the harbour porpoise (Phocoena phocoena) and Risso's dolphin (Grampus griseus).

OBJECTIVES: The temporomandibular joint (TMJ) in cetaceans is largely uncharacterized. This study aims to describe the macroscopic, microscopic, biochemical and biomechanical features of the TMJ of two species of the suborder Odontoceti: the harbour porpoise (Phocoena phocoena) and Risso's dolphin (Grampus griseus). Furthermore, we aim to elucidate the structure-function relationship of their TMJs and their possible role in echolocation. DESIGN: The TMJs from fresh cadaver heads of harbour porpoise (n=4) and Risso's dolphin (n=2) acquired from stranding were examined. Following macroscopical evaluation, the TMJs were investigated for their histological, mechanical and biochemical properties. RESULTS: The TMJs of the studied odontocetes were found to be fundamentally different from other mammals. Macroscopically, the TMJ lacks the typical joint cavity found in most mammals and is essentially a syndesmosis. Histological and microstructural analysis revealed that the TMJ discs were composed of haphazardly intersecting fibrous-connective tissue bundles separated by adipose tissue globules and various calibre blood vessels and nerve fibres. The collagen fibre composition was primarily collagen type I with lesser amounts of collagen type II. Sulphated glycosaminoglycan (sGAG) content was lower compared to other studied mammals. Finally, mechanical testing demonstrated the disc was stronger and stiffer in the dorsoventral direction than in the mediolateral direction. CONCLUSION: The spatial position of the TMJ, the absence of an articulating synovial joint, and the properties of the TMJ discs all reflect the unique suction-feeding mechanism adopted by the harbour porpoise and Risso's dolphin for underwater foraging. In addition, the presence of unique adipose globules, blood vessels and nerves throughout the discs may indicate a functional need beyond food apprehension. Instead, the disc may play a role in neurological sensory functions such as echolocation.

The temporomandibular joint of California sea lions (Zalophus californianus): part 1 - characterisation in health and disease.

OBJECTIVES: This study aimed to characterise the histologic, biomechanical and biochemical properties of the temporomandibular joint (TMJ) of California sea lions. In addition, we sought to identify structure-function relationships and to characterise TMJ lesions found in this species. DESIGN: Temporomandibular joints from fresh cadaver heads (n=14) of California sea lions acquired from strandings were examined macroscopically and microscopically. The specimens were also evaluated for their mechanical and biochemical properties. Furthermore, if TMJ arthritic changes were present, joint characteristics were described and compared to healthy joints. RESULTS: Five male and 9 female specimens demonstrated macroscopically normal fibrocartilaginous articular surfaces and fibrous discs in the TMJ. Out of the 9 female specimens, 4 specimens had TMJ lesions were seen either in the articular surface or the disc. Histologically, these pathologic specimens demonstrated subchondral bone defects, cartilage irregularities and inflammatory cell infiltrates. The normal TMJ discs did not exhibit significant direction dependence in tensile stiffness or strength in the rostrocaudal direction compared with the mediolateral direction among normal discs or discs from affected joints. The TMJ discs were not found to be anisotropic in tensile properties. This feature was further supported by randomly oriented collagen fibres as seen by electron microscopy. Furthermore, no significant differences were detected in biochemical composition of the discs dependent upon population. CONCLUSION: The TMJ and its disc of the California sea lion exhibit similarities but also differences compared to other mammals with regards to structure-function relationships. A fibrous TMJ disc rich in collagen with minimal glycosaminoglycan content was characterised, and random fibre organisation was associated with isotropic mechanical properties in the central region of the disc.

The temporomandibular joint of California sea lions (Zalophus californianus): part 2-osteoarthritic changes.

OBJECTIVES: Following comprehensive characterization of the temporomandibular joint (TMJ) of the California sea lion, as well demonstrating that TMJ-osteoarthritis (OA) occurs in this species, the objective of this part of the investigation was to describe the macroscopic osteologic findings associated with TMJ-OA in a large museum collection of skull specimens. DESIGN: Museum skull specimens (n=497) of California sea lions were examined macroscopically according to defined criteria for the presence, severity, location and characteristics of TMJ-OA. The specimens, acquired from strandings, varied in age from young adults to mature adults. RESULTS: Overall 63.5% of the specimens had findings consistent with TMJ-OA. Of these, 56.2% were from females 43.8% were from males. Moreover, 71.2% specimens were from mature adults and 28.8% from young adults. However, there was no significant association between age and sex with the presence or severity of TMJ-OA. The most prominent TMJ-OA changes were the presence of subchondral bone defects and abnormal porosity. The majority of the OA present at the mandibular head affected the entire articular surface. In contrast, the OA present on the mandibular fossa of the temporal bone was located primarily on the medial aspect (P<0.001). CONCLUSION: The incidence of TMJ-OA in California sea lions is high and varies in severity. Although the significance of the high incidence of this disease in the California sea lion remains elusive, the occurrence and severity of TMJ-OA detected in this study may play an important role in the species' morbidity and mortality.