Temporal memory for threatening events encoded in a haunted house.

Despite the salient experience of encoding threatening events, these memories are prone to distortions and often non-veridical from encoding to recall. Further, threat has been shown to preferentially disrupt the binding of event details and enhance goal-relevant information. While extensive work has characterised distinctive features of emotional memory, research has not fully explored the influence threat has on temporal memory, a process putatively supported by the binding of event details into a temporal context. Two primary competing hypotheses have been proposed; that threat can impair or enhance temporal memory. We analysed two datasets to assess temporal memory for an in-person haunted house experience. In study 1, we examined the temporal structure of memory by characterising memory contiguity in free recall as a function of individual levels of heart rate as a proxy of threat. In study 2, we replicated marginal findings of threat-related increases in memory contiguity found in study 1. We extended these findings by showing threat-related increases in recency discriminations, an explicit test of temporal memory. Together, these findings demonstrate that threat enhances temporal memory regarding free recall structure and during explicit memory judgments.

Adolescent-specific memory effects: evidence from working memory, immediate and long-term recognition memory performance in 8-30 yr olds.

Working memory and recognition memory develop across adolescence, but the relationship between them is not fully understood. We investigated associations between n-back task performance and subsequent recognition memory in a community sample (8-30 yr, n = 150) using tasks from the Adolescent Brain Cognitive Development Study (ABCD Study) to cross-sectionally assess memory in an age range that will be sampled longitudinally. We added a 24-h delay condition to assess long-term recognition. Overall working memory, immediate and long-term recognition performance peaked in adolescence. Age effects in recognition memory varied by items (old targets, old distractors, and new items) and delay (0 and 24 h). For immediate recognition, accuracy was higher for targets and new items than for distractors, with accuracy for targets peaking in adulthood and accuracy for new items peaking during adolescence. For long-term recognition, adolescents' accuracy was higher for targets than distractors, while adults showed similarly high accuracy for targets and distractors and children showed low accuracy for both. This pattern appeared to be specific to recognition of items from the high working memory load condition. The results suggest that working memory may facilitate long-term recognition of task-relevant over irrelevant items and may benefit the detection of new information during adolescence.

An open-access accelerated adult equivalent of the ABCD Study neuroimaging dataset (a-ABCD).

As public access to longitudinal developmental datasets like the Adolescent Brain Cognitive Development StudySM (ABCD Study®) increases, so too does the need for resources to benchmark time-dependent effects. Scan-to-scan changes observed with repeated imaging may reflect development but may also reflect practice effects, day-to-day variability in psychological states, and/or measurement noise. Resources that allow disentangling these time-dependent effects will be useful in quantifying actual developmental change. We present an accelerated adult equivalent of the ABCD Study dataset (a-ABCD) using an identical imaging protocol to acquire magnetic resonance imaging (MRI) structural, diffusion-weighted, resting-state and task-based data from eight adults scanned five times over five weeks. We report on the task-based imaging data (n = 7). In-scanner stop-signal (SST), monetary incentive delay (MID), and emotional n-back (EN-back) task behavioral performance did not change across sessions. Post-scan recognition memory for emotional n-back stimuli, however, did improve as participants became more familiar with the stimuli. Functional MRI analyses revealed that patterns of task-based activation reflecting inhibitory control in the SST, reward success in the MID task, and working memory in the EN-back task were more similar within individuals across repeated scan sessions than between individuals. Within-subject, activity was more consistent across sessions during the EN-back task than in the SST and MID task, demonstrating differences in fMRI data reliability as a function of task. The a-ABCD dataset provides a unique testbed for characterizing the reliability of brain function, structure, and behavior across imaging modalities in adulthood and benchmarking neurodevelopmental change observed in the open-access ABCD Study.

Behavioral and Neural Signatures of Working Memory in Childhood.

Working memory function changes across development and varies across individuals. The patterns of behavior and brain function that track individual differences in working memory during human development, however, are not well understood. Here, we establish associations between working memory, other cognitive abilities, and functional MRI (fMRI) activation in data from over 11,500 9- to 10-year-old children (both sexes) enrolled in the Adolescent Brain Cognitive Development (ABCD) Study, an ongoing longitudinal study in the United States. Behavioral analyses reveal robust relationships between working memory, short-term memory, language skills, and fluid intelligence. Analyses relating out-of-scanner working memory performance to memory-related fMRI activation in an emotional n-back task demonstrate that frontoparietal activity during a working memory challenge indexes working memory performance. This relationship is domain specific, such that fMRI activation related to emotion processing during the emotional n-back task, inhibitory control during a stop-signal task (SST), and reward processing during a monetary incentive delay (MID) task does not track memory abilities. Together, these results inform our understanding of individual differences in working memory in childhood and lay the groundwork for characterizing the ways in which they change across adolescence.SIGNIFICANCE STATEMENT Working memory is a foundational cognitive ability that changes over time and varies across individuals. Here, we analyze data from over 11,500 9- to 10-year-olds to establish relationships between working memory, other cognitive abilities, and frontoparietal brain activity during a working memory challenge, but not during other cognitive challenges. Our results lay the groundwork for assessing longitudinal changes in working memory and predicting later academic and other real-world outcomes.

Implementation of an integrative movement program for residents with dementia in a VA nursing home.

BACKGROUND: Preventing Loss of Independence through Exercise (PLIÉ) is an integrative group movement program developed for adults with mild-to-moderate dementia attending day programs. However, many older adults with dementia ultimately require assistance with their activities of daily living and become residents in nursing homes or other long-term care facilities with their complex comorbidities and unique needs. We conducted a post-implementation evaluation of PLIÉ at a San Francisco Veterans Affairs (VA) nursing home to assess reach and effectiveness among residents, staff, and family members who participated in ≥ 1 PLIÉ class from 9/2018 to 6/2019. METHODS: Post-implementation number of classes offered and mean attendance; anonymous satisfaction surveys (5-point Likert scales); qualitative content analysis of open-ended survey responses and clinical progress notes. RESULTS: Forty-five PLIÉ classes were offered over 9 months. Residents attended an average of 13 ± 12 classes with an average class size of 14 residents, 4 staff members, and 2 family members. Most survey respondents rated the program overall as "very good" or "excellent" (100 % residents, n = 15; 87 % staff, n = 14; 100 % family members, n = 8). Respondents reported improvements in themselves and/or others in four domains: (1) physical, (2) psychological, (3) social, and (4) cognitive. Physical improvements among veterans included mobility, strength, and energy. Psychological improvements included feelings of happiness/well-being, enjoyment, and self-empowerment. Social improvements included connection, social skills, and social support. Cognitive improvements included engagement, communication ability, and focus/attention. Responses were similar among resident, staff, and family member surveys and clinical progress notes. Participants frequently reported improvements in multiple domains (e.g., "The veterans are more alert and engaged, many are smiling and laughing."). Negative comments were primarily related to logistics, suggesting that the class occur more frequently. CONCLUSIONS: PLIÉ was successfully implemented in a VA nursing home with high attendance and satisfaction among residents, staff, and family members. Participants reported clinically meaningful physical, psychological, social, and cognitive benefits. Other long-term care facilities could potentially benefit from implementing PLIÉ to increase quality of life in residents with dementia.

Synthesis of ABBV-168, a 2'-Bromouridine for the Treatment of Hepatitis C.

ABBV-168 is a dihalogenated nucleotide under investigation for the treatment of hepatitis C virus. Three synthetic routes aimed at achieving the stereoselective installation of the C2' gem-Br,F substitution and subsequent Vorbruggen glycosylation were explored to prepare the penultimate nucleoside intermediate. Development culminated in a route to ABBV-168 featuring a de novo chromatography-free furanose synthesis, protecting group-directed Vorbruggen glycosylation, and highly selective phosphoramidation to furnish the API.

The effect of nail characteristics on surface bacterial counts of surgical personnel before and after scrubbing.

OBJECTIVE: To determine the influence of nail characteristics on bacterial counts on the fingers of surgery personnel. STUDY DESIGN: Randomized nonblinded controlled crossover study design. SAMPLE POPULATION: Veterinary students, small animal surgery technicians, small animal surgery interns/residents, and small animal surgery faculty in a veterinary teaching hospital (n = 21). METHODS: Subjects were randomized into one of 2 groups; group 1 wore nail polish (P) for 1 week and group 2 (control) had nonpolished (NP) fingernails. Each subject changed groups the following week. Fingernail lengths were measured each day and fingernail samples were collected before and after presurgical scrub and after surgery. Total bacterial counts (TBC) and suspected staphylococci were counted on blood agar media and mannitol salt agar. The association between bacterial counts and nail biting, position of the volunteer, duration of the surgery, whether the nail polish was chipped, duration of nail polish application, type of surgery, and handedness was tested. Log-transformed CFU counts were compared with a Student's t test and presence or absence of bacteria were compared using Fisher's exact test. RESULTS: TBC, quantities of staphylococci, other gram-positive organisms, and gram-negative bacilli did not differ between P and NP personnel. The only variable associated with higher bacterial counts consisted of nail lengths greater than 2 mm. CONCLUSION: Nail polish did not influence bacterial counts and types of isolates, but nail length is a risk factor for increased bacterial counts. Based on our results, we recommend that nail length be kept under 2 mm.

Can human intelligence safeguard against artificial intelligence? Exploring individual differences in the discernment of human from AI texts.

Artificial intelligence (AI) models can produce output that closely mimics human-generated content. We examined individual differences in the human ability to differentiate human- from AI-generated texts, exploring relationships with fluid intelligence, executive functioning, empathy, and digital habits. Overall, participants exhibited better than chance text discrimination, with substantial variation across individuals. Fluid intelligence strongly predicted differences in the ability to distinguish human from AI, but executive functioning and empathy did not. Meanwhile, heavier smartphone and social media use predicted misattribution of AI content (mistaking it for human). Determinations about the origin of encountered content also affected sharing preferences, with those who were better able to distinguish human from AI indicating a lower likelihood of sharing AI content online. Word-level differences in linguistic composition of the texts did not meaningfully influence participants' judgements. These findings inform our understanding of how individual difference factors may shape the course of human interactions with AI-generated information.

Evaluation of the drawer test and the tibial compression test for differentiating between cranial and caudal stifle subluxation associated with cruciate ligament instability.

OBJECTIVE: To determine the sensitivity and specificity of the drawer test (DT) alone and in combination with the tibial compression test (TCT) to detect stifle subluxation after transection of the cranial cruciate (CrCL), caudal cruciate (CdCL) or both cruciate ligaments (total cruciate ligament or TCL). STUDY DESIGN: Experimental study. SAMPLE POPULATION: Cadaveric, skeletally mature canine pelvic limb pairs (n = 8). METHODS: Pelvic limbs disarticulated at the coxofemoral joint were randomly assigned to the following 1 of 4 groups: (1) limbs had complete transection of the CrCL; (2) limbs had complete transection of the CdCL; (3) limbs had complete transection of both ligaments; and (4) both ligaments were left intact. Participants performed the DT and the TCT and a diagnosis was given based on the DT and on the combination of these tests. RESULTS: DT had a poor sensitivity for correctly identifying CrCL (69%), CdCL (45%), and TCL (26%) rupture, but had a high sensitivity when identifying intact limbs (97%). Specificity for DT was greatest when identifying limbs with CdCL (97%) and TCL (92%) rupture, and the lowest when palpating limbs with CrCL rupture (75%). Combining DT and TCT did not increase sensitivity or specificity values, nor did an increased level of evaluator training. CONCLUSIONS: Independent of evaluator training, the DT alone or combined with the TCT poorly differentiates the cause of stifle instability associated with CrCL, CdCL, and TCL rupture.

Comparison of Trauma in Dogs due to Direct Motor Vehicle Collision or Fall from Open Pick-up Truck Bed during Transportation (2002-2020).

OBJECTIVE: The aim of this study was to report injuries sustained by dogs following motor vehicle trauma: direct motor vehicle collision (MVC), and fall from an open pickup truck bed during transportation (PTB). STUDY DESIGN: Medical records of dogs involved in motor vehicle trauma between 2002 and 2020 were reviewed. Signalment, mode of injury, injuries sustained, and treatments performed were recorded. An owner questionnaire investigated effects of the trauma on the dog and owner. RESULTS: Six hundred and ninety-eight dogs met the inclusion criteria (569 MVC, 102 PTB). Orthopaedic trauma was significantly more common after PTB (90.2%) (MVC, 75.6%; p = 0.011). There were not any differences in the prevalence of soft tissue injuries between groups (76.4% MVC, 67.6% PTB; p = 0.058), however, MVC dogs had significantly more thoracic (26.9% MVC, 4.4% PTB) and abdominal (12.9% MVC, 0% PTB) trauma (p <0.001). Surgical treatments were performed significantly more often after PTB (71.6%) (MVC, 47.6%) (p <0.001). Discharge rate after PTB (95.0%) was significantly higher (MVC, 84.0%) (p <0.001). Aftercare was reported to be significantly more difficult after PTB (76.2%) (MVC, 34.0%; p = 0.002). CONCLUSION: MVC and PTB result in significantly different trauma. PTB causes predominantly orthopaedic and integument injuries, whereas MVC results in thoracic and abdominal trauma. Survival to discharge is greater following PTB than MVC.

Heat generation by two different saw blades used for tibial plateau leveling osteotomies.

During tibial plateau leveling osteotomy (TPLO) the saw blade produces frictional heat. The purpose of this study was to evaluate and compare heat generated by two TPLO blade designs (Slocum Enterprises [SE] and New Generation Devices [NDG]), with or without irrigation, on cadaveric canine tibias. Thirty-six paired tibias were used to continuously measure bone temperatures during osteotomy through both cortices (i.e., the cis and trans cortices). Each pair was assigned to either an irrigation or nonirrigation group during osteotomy, and each tibia within a pair was osteotomized using a different saw blade design. Saw blade temperatures were recorded and temperatures were compared for all combinations of blade type, cortex, and irrigation. In the cis cortex group, the SE blade generated more bone heat than the NGD blade (P=0.0258). Significant differences in temperature generation between saw blade types were seen only when the osteotomy site was not irrigated (P=0.0156). For all variables measured, bone and saw blade temperature generation was lower with irrigation (P<0.05). None of the osteotomies performed with either saw blade produced a critical duration of damaging temperature ranges in this study. Although saw blade design and irrigation influence heat generation during the TPLO, the potential for bone thermal damage during TPLO is low. The use of the NGD blade with irrigation is recommended.

Structure-Based Optimization of ML300-Derived, Noncovalent Inhibitors Targeting the Severe Acute Respiratory Syndrome Coronavirus 3CL Protease (SARS-CoV-2 3CLpro).

Starting from the MLPCN probe compound ML300, a structure-based optimization campaign was initiated against the recent severe acute respiratory syndrome coronavirus (SARS-CoV-2) main protease (3CLpro). X-ray structures of SARS-CoV-1 and SARS-CoV-2 3CLpro enzymes in complex with multiple ML300-based inhibitors, including the original probe ML300, were obtained and proved instrumental in guiding chemistry toward probe compound 41 (CCF0058981). The disclosed inhibitors utilize a noncovalent mode of action and complex in a noncanonical binding mode not observed by peptidic 3CLpro inhibitors. In vitro DMPK profiling highlights key areas where further optimization in the series is required to obtain useful in vivo probes. Antiviral activity was established using a SARS-CoV-2-infected Vero E6 cell viability assay and a plaque formation assay. Compound 41 demonstrates nanomolar activity in these respective assays, comparable in potency to remdesivir. These findings have implications for antiviral development to combat current and future SARS-like zoonotic coronavirus outbreaks.

Turnover of nonessential fatty acids in cardiolipin from the rat heart.

Cardiolipin (CL) is a unique phospholipid (PL) found in the mitochondria of mammalian cells. CL remodeling is accompanied by turnover of its fatty acid acyl groups. Abnormalities in CL remodeling have been found in Barth's syndrome, diabetes, and obesity. The objective of this study was to determine nonessential fatty acid turnover in CL and phosphatidylethanolamine (PE) in the rat heart in vivo. Sprague-Dawley rats were fed either a regular chow or a high-fat diet for 15 weeks, and consumed 6% deuterium-enriched drinking water as a tracer for 14 days. CL and PE were extracted from cardiac tissue and isolated by TLC. Fatty acids from CL, PE, and plasma were analyzed by GC/MS for deuterium incorporation. Results showed oleate and vaccenate turnover were the highest in CL whereas palmitate and stearate turnover were low. Among the nonessential fatty acids in PE, turnover of stearate and vaccenate were the highest. The high turnover rate in vaccenate was unexpected, because vaccenate previously had no known metabolic or physiologic function. In conclusion, the similarly high turnover rates of both oleate and vaccenate readily suggest that remodeling is an important functional aspect of PL metabolism in CL.

Effects of 6% hetastarch (600/0.75) or lactated Ringer's solution on hemostatic variables and clinical bleeding in healthy dogs anesthetized for orthopedic surgery.

OBJECTIVE: To evaluate and compare hemostatic variables and clinical bleeding following the administration of 6% hetastarch (600/0.75) or lactated Ringer's solution (LRS) to dogs anesthetized for orthopedic surgery. STUDY DESIGN: Randomized blinded prospective study. ANIMALS: Fourteen, healthy adult mixed-breed hound dogs of either sex, aged 11-13 months, and weighing 20.8±1.2 kg. METHODS: The dogs were randomly assigned to receive a 10 mL kg(-1) intravenous (i.v.) bolus of either 6% hetastarch (600/0.75) or LRS over 20 minutes followed by a maintenance infusion of LRS (10 mL kg(-1)  hour(-1)) during anesthesia. Before (Baseline) and at 1 and 24 hours after bolus administration, packed cell volume (PCV), total protein concentration (TP), prothrombin time (PT), activated partial thromboplastin time (APTT), von Willebrand's factor antigen concentration (vWF:Ag), factor VIII coagulant activity (F VIII:C), platelet count, platelet aggregation, colloid osmotic pressure (COP) and buccal mucosal bleeding time (BMBT) were measured. In addition a surgeon who was blinded to the treatments assessed bleeding from the incision site during the procedure and at 1 and 24 hours after the bolus administration. RESULTS: Following hetastarch or LRS administration, the PCV and TP decreased significantly 1-hour post-infusion. APTT did not change significantly compared to baseline in either treatment group, but the PT was significantly longer at 1-hour post-infusion than at 24 hours in both groups. No significant change was detected for vWF:Ag, FVIII:C, platelet aggregation or clinical bleeding in either group. The BMBT increased while platelet count decreased significantly at 1-hour post-infusion in both groups. The COP decreased significantly in both treatment groups 1-hour post-infusion but was significantly higher 1-hour post-infusion in the hetastarch group compared to the LRS group. CONCLUSIONS AND CLINICAL RELEVANCE: At the doses administered, both hetastarch and LRS can alter hemostatic variables in healthy dogs. However, in these dogs undergoing orthopedic surgery, neither fluid was associated with increased clinical bleeding.

Agent Orange Exposure and Dementia Diagnosis in US Veterans of the Vietnam Era.

Importance: Agent Orange is a powerful herbicide that contains dioxin and was used during the Vietnam War. Although prior studies have found that Agent Orange exposure is associated with increased risk of a wide range of conditions, including neurologic disorders (eg, Parkinson disease), metabolic disorders (eg, type 2 diabetes), and systemic amyloidosis, the association between Agent Orange and dementia remains unclear. Objective: To examine the association between Agent Orange exposure and incident dementia diagnosis in US veterans of the Vietnam era. Design, Setting, and Participants: This cohort study included Veterans Health Administration data from October 1, 2001, and September 30, 2015, with up to 14 years of follow-up. Analyses were performed from July 2018 to October 2020. A 2% random sample of US veterans of the Vietnam era who received inpatient or outpatient Veterans Health Administration care, excluding those with dementia at baseline, those without follow-up visits, and those with unclear Agent Orange exposure status. Exposures: Presumed Agent Orange exposure documented in electronic health record. Main Outcomes and Measures: Fine-Gray competing risk models were used to compare the time to dementia diagnosis (with age as the time scale) for veterans with vs without presumed Agent Orange exposure (as per medical records), adjusting for demographic variables and medical and psychiatric comorbidities. Results: The total sample was 511 189 individuals; after exclusions, 316 351 were included in analyses. Veterans were mostly male (n = 309 889 [98.0%]) and had a mean (SD) age of 62 (6.6) years; 38 121 (12.1%) had presumed Agent Orange exposure. Prevalence of most conditions, including Parkinson disease, diabetes, and amyloidosis, was similar at baseline among veterans with and without Agent Orange exposure. After adjusting for demographic variables and comorbidities, veterans exposed to Agent Orange were nearly twice as likely as those not exposed to receive a dementia diagnosis over a mean (SD) of 5.5 (3.8) years of follow-up (1918 of 38 121 [5.0%] vs 6886 of 278 230 [2.5%]; adjusted hazard ratio: 1.68 [95% CI, 1.59-1.77]). Veterans with Agent Orange exposure developed dementia at a mean of 1.25 years earlier (at a mean [SD] age of 67.5 [7.0] vs 68.8 [8.0] years). Conclusions and Relevance: Veterans with Agent Orange exposure were nearly twice as likely to be diagnosed with dementia, even after adjusting for the competing risk of death, demographic variables, and medical and psychiatric comorbidities. Additional studies are needed to examine potential mechanisms underlying the association between Agent Orange exposure and dementia.

Preventing Loss of Independence through Exercise (PLIÉ): A Pilot Trial in Older Adults with Subjective Memory Decline and Mild Cognitive Impairment.

BACKGROUND: Preventing Loss of Independence through Exercise (PLIÉ) is a group movement program initially developed for people with mild-to-moderate dementia that integrates principles from several well-established traditions to specifically address the needs of people with cognitive impairment. OBJECTIVE: To investigate whether PLIÉ would benefit cognitive and behavioral outcomes and functional brain connectivity in older adults with milder forms of cognitive impairment. METHODS: Participants (≥55 y) with subjective memory decline (SMD) or mild cognitive impairment (MCI) were assessed with tests of cognitive and physical function, self-report questionnaires, and resting state functional magnetic resonance imaging (rs-fMRI) on a 3 Tesla scanner before and after participating in twice weekly PLIÉ classes for 12 weeks at the San Francisco Veterans Affairs Medical Center. RESULTS: Eighteen participants completed the pre-post intervention pilot trial. We observed significant improvements on the Alzheimer's Disease Assessment Scale cognitive subscale (ADAS-cog; effect size 0.34, p = 0.002) and enhanced functional connections between the medial prefrontal cortex (mPFC) and other nodes of the default mode network (DMN) after PLIÉ. Improvements (i.e., lower scores) on ADAS-cog were significantly correlated with enhanced functional connectivity between the mPFC and left lateral parietal cortex (Spearman's ρ= -0.74, p = 0.001) and between the mPFC and right hippocampus (Spearman's ρ= -0.83, p = 0.001). After completing PLIÉ, participants reported significant reductions in feelings of social isolation and improvements in well-being and interoceptive self-regulation. CONCLUSION: These preliminary findings of post-PLIÉ improvements in DMN functional connectivity, cognition, interoceptive self-regulation, well-being and reduced feelings of social isolation warrant larger randomized, controlled trials of PLIÉ in older adults with SMD and MCI.

Feel the bass: Music presented to tactile and auditory modalities increases aesthetic appreciation and body movement.

Music is both heard and felt-tactile sensation is especially pronounced for bass frequencies. Although bass frequencies have been associated with enhanced bodily movement, time perception, and groove (the musical quality that compels movement), the underlying mechanism remains unclear. In 2 experiments, we presented high-groove music to auditory and tactile senses and examined whether tactile sensation affected body movement and ratings of enjoyment and groove. In Experiment 1, participants (N = 22) sat in a parked car and listened to music clips over sound-isolating earphones (auditory-only condition), and over earphones plus a subwoofer that stimulated the body (auditory-tactile condition). Experiment 2 (N = 18) also presented music in auditory-only and auditory-tactile conditions, but used a vibrotactile backpack to stimulate the body and included 2 loudness levels. Participants tapped their finger with each clip, rated each clip, and, in Experiment 1, we additionally video recorded spontaneous body movement. Results showed that the auditory-tactile condition yielded more forceful tapping, more spontaneous body movement, and higher ratings of groove and enjoyment. Loudness had a small, but significant, effect on ratings. In sum, findings suggest that bass felt in the body produces a multimodal auditory-tactile percept that promotes movement through the close connection between tactile and motor systems. We discuss links to embodied aesthetics and applications of tactile stimulation to boost rhythmic movement and reduce hearing damage. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Potential iatrogenic medial meniscal damage during tibial plateau leveling osteotomy.

OBJECTIVE: To evaluate potential iatrogenic medial meniscal (MM) damage during tibial plateau leveling osteotomy (TPLO) and to establish a safe zone (SZ) for hypodermic needle (HN) identification of the medial aspect of the stifle joint. STUDY DESIGN: Prospective cohort. ANIMALS: Cadaveric canine stifles (n=40). METHODS: HN (20 or 25 G) were inserted through the medial collateral ligament (MCL) of the femorotibial joint and through the SZ insertion points. The medial meniscus was inspected for iatrogenic damage. Statistical comparison of MM damage caused by different needle sizes and insertion sites was performed using Fisher's exact test with significance at P< .05. RESULTS: Twenty-gauge group: 65% of stifles had minor MM damage with MCL insertion compared with 35% of stifles with SZ insertion (P=.0049). Severe MM damage occurred in 25% of stifles with MCL insertion compared with 0% of stifles with SZ insertion (P=.0014). Twenty-five-gauge group: 85% of stifles had minor MM damage with MCL insertion compared with 30% after SZ insertion (P=.0011); however, no severe MM injury was noted. CONCLUSIONS: HN insertion though the MCL can produce iatrogenic damage to the MM. Use of a 25 G HN and SZ site for insertion reduced the frequency and severity of MM damage. CLINICAL RELEVANCE: HN insertion into the medial aspect of the femorotibial joint during TPLO can cause gross iatrogenic MM damage, which may contribute to the incidence and misdiagnosis of latent MM injuries after TPLO.

Surgical treatment of mineralized and nonmineralized supraspinatus tendinopathy in twenty-four dogs.

OBJECTIVE: To report and compare the clinical diagnosis, surgical treatment, histopathologic changes, and outcomes of dogs with mineralized and nonmineralized supraspinatus tendinopathy (ST). STUDY DESIGN: Case series. ANIMALS: Dogs (n=24) with ST. METHODS: Medical records (1995-2006) of dogs with ST that had surgical treatment were reviewed. Results of clinical examination, diagnostic imaging, surgery, histopathology of resected tendon tissue, and outcome were compared between dogs with mineralized and nonmineralized ST. RESULTS: There were 15 dogs with mineralized ST and 9 with nonmineralized ST. Chronic, unilateral, intermittent or waxing-waning lameness, and pain elicited on palpation of the cranial aspect of the shoulder were the most consistent findings. On ultrasonographic or magnetic resonance imaging (MRI) of 35 shoulders, enlargement of the supraspinatus tendon (54%), increased fluid content (63%), and medial displacement of the biceps tendon (60%) were observed. Eleven of 12 dogs with bilateral abnormalities only had unilateral lameness. Surgery was performed in 30 shoulders. Resected tendon specimens had myxomatous degeneration and/or cartilaginous metaplasia in 11 of 13 dogs in the mineralized group and all 9 dogs in the nonmineralized group. Functional outcome after surgery was poor in 3 dogs and good-to-excellent in 16. CONCLUSIONS: Mineralized and nonmineralized ST have many similarities. Although lameness is usually unilateral, the supraspinatus tendon may be affected bilaterally. CLINICAL RELEVANCE: Ultrasonography and MRI are good imaging techniques for detection of ST especially the nonmineralized form. Surgical treatment results in good recovery of limb function. Nonmineralized ST is a recently described disorder in dogs and evaluation of more cases is necessary to determine outcome after surgical or medical treatment.

Arthropathy caused by a lead bullet in a dog.

CASE DESCRIPTION: A 3-year-old spayed female Labrador Retriever was evaluated for progressive lameness of the left forelimb 21 months after being shot in the elbow with a lead bullet. CLINICAL FINDINGS: Physical examination findings were consistent with moderate osteoarthritis of the left elbow joint. Orthogonal radiographic views of the elbow revealed multiple metallic fragments in and around the joint space as well as signs of osteoarthritis. TREATMENT AND OUTCOME: The elbow joint was evaluated arthroscopically. A lead-based bullet fragment was seen in the lateral synovial compartment and removed in multiple pieces. Excess fibrin and synovium were removed, and microfractures were created in exposed subchondral bone to stimulate neovascularization and fibrocartilage formation. In a follow-up telephone conversation 4 months after surgery, the owner reported a marked improvement in the lameness. CLINICAL RELEVANCE: Removal of lead intra-articular foreign bodies may be indicated even if the material is not believed to mechanically interfere with joint motion.