The effects of ascorbic acid on skeletal muscle blood flow in aged rats

Master of ScienceDepartment of KinesiologyTimothy I. MuschDuring exercise aged individuals exhibit endothelial dysfunction and decreased levels of whole-limb blood flow (BF), both of which may be linked mechanistically to age-related increases in reactive oxygen species (ROS). Ascorbic acid (AA) reduces levels of ROS and has been shown to alleviate vascular and hyperemic dysfunction at rest (Jablonski et al., 2007) and during small muscle mass exercise in humans (Kirby et al., 2009). However, the effect of AA on vascular function and BF to individual muscles during whole-body exercise is not known. PURPOSE: To test the hypothesis that a single high-dose infusion of AA would increase BF to the hindlimb musculature of old rats at rest and during treadmill running. METHODS: 18 old (~28 months) Fischer 344 x Brown Norway rats were randomized into rest (n=9) and exercise (n=9) groups. BF to the total hindlimb and individual muscles (28 individual muscles and muscle parts) was evaluated via radiolabeled microspheres before and after intra-arterial AA administration (76 mg/kg in 3 ml heparinized saline, 30 minute infusion) at rest and during submaximal treadmill running (20m/min, 5% grade). Total antioxidant capacity (TAC) and thiobarbituric acid reactive species (TBARS) were measured before and after AA to determine the ability of this specific dose of AA to increase levels of plasma antioxidants and decrease levels of ROS, respectively. RESULTS: At rest: AA increased TAC (~37%, P0.05). AA decreased total hindlimb BF (Pre: 25±3 vs Post: 16±2 ml/min/100g, P0.05) or BF to any of the individual muscles evaluated. CONCLUSIONS: Increased TAC via AA infusion reduces hindlimb muscle BF at rest but had no effect on BF during whole-body dynamic exercise. Thus, even though TBARS decreased, there was no evidence that AA supplementation increases blood flow to the locomotor muscles of old rats during whole-body exercise

Liposomal Bupivacaine in Total Knee Arthroplasty: Preliminary Results of a Two-Surgeon, Retrospective Study

INTRODUCTION: Liposomal bupivacaine (LB) is a slowly degrading preparation that provides local anesthesia for up to 72 hours. It targets the site directly responsible for pain sensation, with no associated motor blockade. In total knee arthroplasty (TKA), it may have superior outcomes to anesthesia with regional nerve block. METHODS: Our surgeons began using LB in TKA patients in 2013. All patients following each surgeon’s LB start date were the experimental group. An equivalent number of patients prior to 2013 served as the control group. All control group patients received a preoperative femoral nerve block, and all experimental group patients received peri- and intra-articular LB, delivered intraoperatively. All other surgical and anesthesia interventions were the same. We used retrospective chart review to identify patient demographics, time to first ambulation, time to discharge, and incidence of postoperative nausea and vomiting. We also recorded opioid consumption intraoperatively, in the recovery room, and on the floor. RESULTS: There were 161 patients in each group. We found no significant difference between the two groups with regard to gender, age, weight, preoperative opioid exposure, side of procedure, type of anesthesia (general vs. spinal), or ASA status. On average, LB patients consumed 29.2% less opioid after leaving the recovery room (p DISCUSSION AND CONCLUSION: With increasing focus on the cost of TKA, there is strong incentive to manage costs associated with the procedure. Additionally, all patients, regardless of comorbid conditions, can benefit from limited exposure to narcotic pain medication. Our results indicate that LB decreases total systemic opioid requirement, time to first ambulation, and time to discharge from the hospital

A Retrospective Analysis of Opioid Consumption Among Different Orthopedic Surgeons for Total Joint Replacement

Background: Throughout the world, baby boomers reaching their sixth, seventh, and eighth decade of life are requiring a significant number of joint replacements—hips and knees. Due to the increasing number of joint replacements, it is important to find a multi-modal approach (MMA) to control pain, reduce the amount of opioid consumption, and improve patient satisfaction. Purpose: The purpose of this study was to evaluate the intraoperative, postoperative, and total opioid consumption of patients undergoing total hip and knee replacements in an effort to develop a multi-modal approach to decrease opioid consumption, minimize adverse effects secondary to narcotic administration, and to achieve better pain control. This MMA was achieved by administering oxycodone, gabapentin, celecoxib, and acetaminophen starting before surgical incision. Methods: The study sample consisted of 192 patients undergoing total hip and knee replacements over a 10-month period between June 2012 and March 2013 at UMASS Memorial performed by five orthopedic surgeons. The main objective was to record intraoperative, postoperative, total opioid consumption, and patient satisfaction amongst these patients. Furthermore, the patients were subdivided based on the type of procedure (hip vs knee), type of anesthetic (general vs spinal), and the presence or absence of an indwelling catheter to deliver anesthetic (catheter vs no catheter). Results: The data showed a large variability among the surgeons in regards to the amount of opioid used intraoperatively, postoperatively and total opioid consumption. In terms of type of anesthetic, the patients undergoing spinal anesthesia used statistically significantly less opioids intraoperatively but not postoperatively, compared to general anesthesia. As for catheter use with general and spinal anesthesia, surprisingly, there was no significant difference in opioid consumption compared to the non-catheter counterpart. Furthermore, there seems to be no correlation between body mass index (BMI) and intraoperative or postoperative opioid use. Patient satisfaction was another variable that showed no correlation with opioid use intraoperatively or postoperatively. In terms of age, the data suggests that older patients use less opioids postoperatively in both hip and knee replacements. Conclusions: Our results quantitatively show spinal anesthesia to be far superior than general anesthesia in both joint replacements. Spinal anesthesia provides better pain control intraoperatively which allows one to use less opioids, thereby minimizing the adverse side effects of narcotic administration which include respiratory depression, urinary retention, nausea and post-operative ileus to name just a few. One surgeon’s patients required significantly less opioids intraoperatively compared to the rest of the surgeons. Further studies might warrant examining this surgeon’s technique or the demographics of his patient population to determine how better pain control and less opioid consumption could be achieved across all joints with all participating surgeons

Prolonged In Vivo Retention of a Cathepsin D Targeted Optical Contrast Agent in a Mouse Model of Alzheimer\u27s Disease.

BACKGROUND: Cathepsin D (CatD) is a lysosomal protease that is elevated early in Alzheimer\u27s disease (AD). We have previously developed a Targeted contrast agent (CA) to detect CatD activity in vivo, consisting of a magnetic resonance imaging/fluorescent moiety linked to a cell penetrating peptide (CPP) by means of a CatD cleavage site and have demonstrated its uptake in the brain of an AD mouse model. OBJECTIVE: The purpose of this study was to characterize the in vivo retention of a near infra-red fluorescent dye labeled version of this CA. METHODS: Six adult C57Bl/6 wild-type mice and six adult 5XFAD transgenic AD mice were studied using a small animal imaging system at five and twelve months of age using our novel Targeted CA, or two different control CAs; a Non-Targeted (lacking the CatD cleavage site) and a Non-Penetrating (lacking the CPP). Following intravenous CA administration, the optical signal was recorded within the brain and uptake and washout curves were measured and fitted to a one-phase exponential decay curve. RESULTS: In all wild-type and 5XFAD mice, the washout of the Targeted CA that included a CPP domain was significantly slower than the washout of the Non-Penetrating and Non-Targeted CA. Furthermore, the washout of the CatD Targeted CA was significantly slower in the 5XFAD mice compared to the age matched wild-type controls (p \u3c  0.05) at 5 and 12 months of age. Control CAs showed no differences in washout. CONCLUSIONS: The prolonged retention of the CatD targeted CA in 5XFAD mice suggests this agent may be useful for AD detection

The Dietary Ecology of Ring-Tailed Lemurs As Reflected By δ13C and δ15N Stable Isotope Values

Madagascar is one of the top global hotspots for biodiversity (Yoder \u26 Nowak, 2006). Yet it is experiencing high rates of habitat loss, especially gallery forest, an important resource to many endemic primate species (Sauther et al., 1999; Sussman \u26 Rakotozafy, 1994). Natural disasters such as Madagascar\u27s cyclical droughts and cyclones may compound the effects of habitat loss (Gould et al., 1999; Whitelaw, 2010; Wright, 1999). Changes in dietary ecology as a result of these events may be reflected in altered hair δ13C and δ15N values from the study population. By studying how lemurs respond to cyclone and drought habitat disturbance, researchers can better understand how forest destruction and non-native species introduction by humans might impact the ability of lemurs to effectively react for continued survival. This study looks at the effects of habitat disturbance on four endemic Malagasy ring-tailed lemur troops via stable carbon and nitrogen isotope values of hair samples collected between 2003-2006. Severe droughts affected the region in 2004 and 2006. In January 2005, cyclone Ernest hit southwestern Madagascar causing widespread defoliation, tree falls, and a decrease in food availability (Whitelaw, 2010). δ13C and δ15N values shifted in a non-uniform pattern based on both troop and year. This suggests ring-tailed lemur dietary strategies may vary between troops and depending on what environmental effects are present. During normal years, troops may compete over highly desirable resources. During a drought, they may focus on a few less preferred but abundant resources, reducing their dietary diversity. After a cyclone, the drought resistant resources may no longer be widely available, increasing intra-troop competition and requiring ring-tailed lemurs to broaden their dietary diversity. Because they are synchronous group feeders (Sauther et al., 1999), a low availability of any single resource may require them to also increase dietary diversity within the troop, forcing individuals to utilize different types of resources. This explanation is one possible interpretation supported by the δ13C and δ15N values presented in this thesis

Foster Care: A Survey of Factors Leading to Long Term Foster Care; Angel Guardian Home, Brooklyn, New York 1964

Abstract not availabl