Comparison of three methods for nucleus pulposus volume measurement in rabbit lumbar spines: a preclinical model for measurement of the effectiveness of prophylactic intervertebral disk fenestration in dogs.

OBJECTIVE: Compare 3 methods of nucleus pulposus (NP) volume measurement using the rabbit lumbar spines as a preclinical model to determine the effectiveness of prophylactic intervertebral disk fenestration in dogs. ANIMALS: Twelve 9-month-old, skeletally mature female entire New Zealand White rabbits weighing between 3.5 to 4.5 kg. METHODS: NP volume measurements of dissected rabbit lumber spines between L1 and L6 were made and compared using gross measurements, reconstructed MRI images, and water volumetry based on Archimedes' principle. Water volumetry was used as the true gold standard volume measurement in this study. RESULTS: The true volume (mean ± SD) of the nucleus pulposus NP as measured by water volumetry increased caudally from L1/L2 (16.26 ± 3.32 mm3) to L5/L6 (22.73 ± 6.09 mm3). Volume estimates made by MRI were significantly higher than those made using water volumetry at all sites (L1/L2 [P = .044], L2/L3 [P = .012], L3/L4 [P = .015], L4/L5 [P < .001], and L5/L6 [P < .001]). Gross measurements also significantly overestimated volume when compared to water volumetry at all sites; L1/L2 (P = .021), L2/L3 (P = .025), L3/L4 (P = .001), L4/L5 (P < .001), and L5/L6 (P < .001). MRI and gross volume estimates were significantly different at L4/L5 (P = .035) and L5/L6 (P = .030). CLINICAL RELEVANCE: The findings of this preclinical model might be relevant to veterinary surgeons who perform prophylactic fenestration for which there is no reliable method to determine the amount of NP to be removed. Preclinical ex vivo and in vivo fenestration studies with pre- and postoperative NP volume assessment are required.

Morphometric description of the koala humerus using microcomputed tomography.

The current prognosis for successful return to function in koalas with appendicular fractures is poor despite being the most common fracture type to result in successful rehabilitation. The forelimb, particularly the humerus, plays a critical role in stabilisation and support while climbing trees. Successful rehabilitation therefore requires adequate internal stabilisation to promote bone healing and faster return to function. Current knowledge of koala limb bone morphometry is lacking and would provide useful clinical insight for future orthopaedic research, particularly with regards to recommendations regarding implant size and type. In this study microcomputed tomography (micro-CT) was used to describe bone length, internal and external diameters, and cortical thickness at five transverse levels along the humerus of skeletally mature koala cadavers. Qualitative descriptions were also made regarding bone features deemed clinically relevant to potential fracture repair techniques. Mean humeral length was 114.3 mm (95% CI 107.29-121.31 mm). Mediolateral diameters were greater than craniocaudal diameters at each measurement level, and the diaphysis has a distally tapering medullary cavity. Diaphyseal cortices were relatively homogenous with slight distal thickening, and medial cortices were thickest along the entire bone. The bone protuberances of the deltoid and supinator ridges projected most of the way down the lateral surface of the bone while the medial surface remained relatively uniform. Distal to the deltoid ridge the humerus curved caudally, terminating at a craniocaudally flattened distal epiphysis. Morphometric descriptions provided in this study will serve as a useful reference for future research, guiding orthopaedic surgery and improving prognosis of koala humeral fractures.

Assessing the impacts of COVID-19 on activity-travel scheduling: A survey in the greater Toronto area.

The COVID-19 lockdown provided many individuals an opportunity to explore changes in their daily routines, particularly when considered in combination with an ever-changing Information and Communication Technology (ICT) landscape. These new routines and alternative activities have the potential to be continued in the post-COVID era. Transportation planners must understand how routines vary to effectively estimate activity-travel scheduling. The purpose of this study is to determine the influence of the COVID-19 pandemic lockdown on activity-travel behavior and the adoption of ICT-based alternative options. A special emphasis is placed on predicting the long-term effects of this disturbance on activity-travel scheduling. This study examines the changes in the frequency and mode of completing five of the most repetitious tasks in the daily schedule (working, grocery and non-grocery shopping, preparing/eating meals, and visiting family/friends) during the lockdown and immediately after reopening. We find an increased preference for home meal preparation over online ordering and a reluctance to engage in in-person shopping until a substantial proportion of the population has acquired a vaccination against the virus. Respondents prefer to work from home if they have adequate access to home office materials (e.g., desk, chair, computer monitor). Individuals with children must also consider suitable childcare before considering a return to work.

Thiazolidinediones in patients with type 2 diabetes mellitus and heart failure.

PURPOSE: A review of the significant findings related to the use of the thiazolidinediones (TZDs) in the treatment of patients with type 2 diabetes mellitus and heart failure was conducted. SUMMARY: TZDs are antihyperglycemic medications that increase insulin sensitivity and improve the underlying defect of insulin resistance and type 2 diabetes mellitus, and they have the potential to slow or decrease the cardiovascular damage that results from these conditions. TZDs are also implicated in weight gain; however, this is accompanied by an improvement in insulin sensitivity and, therefore, its clinical significance is unclear. Edema has been well characterized in patients treated with TZDs. Edema is more common in patients treated with a TZD in combination with insulin and higher doses of TZDs. Because of the potential for fluid retention and worsening edema, clinical studies have excluded patients with New York Heart Association (NYHA) functional class III or IV heart failure. In patients at risk for heart failure or those who have NYHA functional class I or II symptoms, initiation of therapy should be at the lower dose for TZDs with close monitoring of weight gain, edema, and other signs of worsening heart failure. CONCLUSION: Current data suggest that TZDs may be used cautiously in patients with type 2 diabetes mellitus who are at risk for heart failure or who have NYHA functional class I or II heart failure. Patients with NYHA functional class III or IV heart failure should not receive TZDs.

Cost evaluation of risperidone compared with olanzapine.

This study evaluated costs associated with risperidone and olanzapine treatment for schizophrenia. Data were collected from the Department of Veterans Affairs computerized database nine months before and nine months after patients began continuous treatment with risperidone (N=23) or olanzapine (N=47). Both agents were associated with significant reductions in psychiatric hospitalization costs. Median increases in antipsychotic costs were significantly higher for patients treated with olanzapine ($1,892) than for those treated with risperidone ($733). Mean dosages were 3.5 mg per day for the risperidone group and 18 mg per day for the olanzapine group. Although both treatments were associated with similar reductions in costs of psychiatric inpatient and outpatient care, it was significantly less expensive to prescribe risperidone than olanzapine.