Extinction in the developing rat: an examination of renewal effects

In the present series of experiments the context-specificity of extinction was examined from a developmental perspective. For postnatal day (PN) 23 rats, renewal of freezing to an aversive odor conditioned stimulus (CS) was observed when rats were conditioned in Context A, extinguished in Context B, and tested in Context A (i.e., ABA renewal). This effect was not observed in PN16 rats, which is consistent with previous studies suggesting that rats < approximately PN20 are impaired in encoding contextual information [i.e., Carew and Rudy [1991]. Developmental Psychobiology, 24, 191-209]. Subsequent experiments demonstrated that for rats conditioned at PN16 and tested at PN23, contextual regulation of extinction performance depended on the age at which extinction occurred. Specifically, ABA renewal was observed in rats given extinction training at PN22 but not in rats given extinction training at PN17. These latter results show that whether or not context regulates the expression of an ambiguous memory is determined by the animal's age when the memory becomes ambiguous.     

Occlusion and periodontal disease--where is the link?

The effect of occlusion on the periodontium has been the subject of much debate. Interest on this subject has decreased over the years but has been renewed with the popularity of implant dentistry. This paper reviews the literature and explores the relationship between trauma from occlusion with periodontal disease and peri-implant bone loss. With regards to periodontal disease, there are two schools of thought on the effect that trauma from occlusion has on the periodontium. One believes that trauma from occlusion is a co-destructive factor in the initiation and progression of periodontal disease. The other believes that it is not. Up till now, there are no conclusive explanations on the association between trauma from occlusion and periodontal disease. For dental implants, current literature suggests that there is an association between occlusal overloading and peri-implant bone loss even in the absence of inflammation. However, there is a need for more randomized clinical trials to validate this relationship.     

Physicomechanical evaluation of low-shrinkage dental nanocomposites based on silsesquioxane cores

This study aimed to determine the modulus, hardness, and polymerization shrinkage of novel silsesquioxane (SSQ)-based nanocomposites synthesized for dental applications. Four novel SSQ materials were developed and mixed with control monomers in 5, 10, 20, and 50 wt% SSQ nanocomposite ratios and were evaluated for use as potential low-shrinkage composite restoratives. The postgel polymerization shrinkage of the hybrid materials was then investigated and compared with unfilled 1:1 (control) bisphenol A glycerolate (1 glycerol/phenol) dimethacrylate/tri(ethylene glycol) dimethacrylate (Bis-GMA/TEGDMA) materials using a strain-monitoring device and test configuration. Mechanical properties, such as hardness and modulus, were determined using the depth-sensing microindentation approach. All samples investigated were polymerized using a dental light-curing unit (BISCO VIP) at 500 mW cm(-2) for 40 s. The results obtained were analyzed using analysis of variance/Scheffe's posthoc test at a significance level of 0.05. At 60 min postlight polymerization, postgel shrinkage associated with the control was found to be significantly higher than for all control/SSQ mixtures. Hardness and modulus were found to decrease with increased amount of SSQ monomers added, indicating that the incorporation of SSQ monomers into the control generally helps to reduce both the rigidity and the polymerization shrinkage. Therefore, in the correct formulation, SSQ materials have great potential to be used as low-shrinkage composite restoratives.     

Delayed Gastric Emptying After Sleeve Gastrectomy Is Associated with Poor Weight Loss

Obesity Surgery - Intermediate to long-term weight regain is a major challenge following sleeve gastrectomy (SG). Physiological changes that mediate the extent of weight loss remain unclear. We...     

Clinical and economic burden of wound care in the tropics: a 5‐year institutional population health review

The aim of this study is to evaluate the clinical and economic burden of wound care in the Tropics via a 5‐year institutional population health review. Within our data analysis, wounds are broadly classified into neuro‐ischaemic ulcers (NIUs), venous leg ulcers (VLUs), pressure injuries (PIs), and surgical site infections (SSIs). Between 2013 and 2017, there were a total of 56 583 wound‐related inpatient admissions for 41 461 patients, with a 95.1% increase in wound episodes per 1000 inpatient admissions over this period (142 and 277 wound episodes per 1000 inpatient admissions in 2013 and 2017, respectively). In 2017, the average length of stay for each wound episode was 17.7 days, which was 2.4 times that of an average acute admission at our institution. The average gross charge per wound episode was USD $12 967. Among the 12 218 patients with 16 674 wound episodes in 2017, 71.5% were more than 65 years of age with an average Charlson Comorbidity Index (CCI) of 7.2. Half (51.9%) were moderately or severely frail, while 41.3% had two or more wound‐related admission episodes. In 2017, within our healthcare cluster, the gross healthcare costs for all inpatient wound episodes stand at USD $216 million within hospital care and USD $596 000 within primary care. Most NIU patients (97.2%) had diabetes and they had the most comorbidities (average CCI 8.4) and were the frailest group of patients (44.9% severely frail). The majority of the VLU disease burden was at the specialist outpatient setting, with the average 1‐year VLU recurrence rate at 52.5% and median time between healing and recurrence at 9.5 months. PI patients were the oldest (86.5% more than 65 years‐old), constituted the largest cohort of patients with 3874 patients at an incidence of 64.6 per 1000 admissions in 2017, and have a 1‐year all‐cause mortality rate of 14.3%. For SSI patients, there was a 125% increase of 14.2 SSI wound episodes per 1000 inpatient admissions in 2013 to 32.0 in 2017, and a 413% increase in wound‐related 30‐day re‐admissions, from 40 in 2013 (4.1% of all surgeries) to 205 (8.3% of all surgeries) in 2017. The estimated gross healthcare cost per patient ranges from USD $15789–17 761 across the wound categories. Similar to global data, there is a significant and rising trend in the clinical and economic burden of wound care in Tropics.     

Utilization of peritoneal dialysis in the United States: Reasons for underutilization,specifically in New York State and the boroughs of New York City

Peritoneal dialysis (PD) is currently underutilized in the United States (US), even within resource-rich neighborhoods. We analyzed data from US Renal Data Service to determine PD utilization within the US, New York State (NYS), selected boroughs within New York City (NYC), and Boston, Massachusetts. We then compared the odds of selecting PD with hemodialysis (HD) and analyzed how diabetes mellitus status, age >65 years, gender, and race influenced PD utilization between 2010 and 2016. We then compared a high-volume PD center (HVC) with a low-volume PD center (LVC). The odds of starting PD vs HD were as follows: Brooklyn 0.30 (0.25-0.36; <0.0001), Bronx 0.56 (0.47-0.67; <0.0001), Queens 0.66 (0.54-0.80; <0.0001), and Manhattan 0.61 (0.52-0.71; <0.0001). In 2016, the odds of starting PD compared with the rest of the US were as follows: Brooklyn 0.14 (0.08-0.22; <0.0001), Bronx 0.39 (0.27-0.56; <0.0001), Queens 0.32 (0.23-0.45; <0.0001), Manhattan 0.54 (0.36-0.79; 0.002), and Boston 0.89 (0.58-1.4; 0.624). Analysis of influencing factors showed that only age >65 significantly (<0.0001) influenced PD modality selection in Brooklyn and Boston. Differences between HVC and LVC in terms of modality transition, peritonitis rate, or provider:patient ratio were not statistically significant. Factors that influence PD utilization in urban neighborhoods are discussed and remediation measures are proposed.     

Comparing Effectiveness of High-Fidelity Human Patient Simulation vs Case-Based Learning in Pharmacy Education

Objective. To determine whether human patient simulation (HPS) is superior to case-based learning (CBL) in teaching diabetic ketoacidosis (DKA) and thyroid storm (TS) to pharmacy students.Design. In this cross-over, open-label, single center, randomized control trial, final-year undergraduate pharmacy students enrolled in an applied therapeutics course were randomized to HPS or CBL groups. Pretest, posttest, knowledge retention tests, and satisfaction survey were administered to students.Assessment. One hundred seventy-four students participated in this study. The effect sizes attributable to HPS were larger than CBL in both cases. HPS groups performed significantly better in posttest and knowledge retention test compared to CBL groups pertaining to TS case (p<0.05). Students expressed high levels of satisfaction with HPS sessions.Conclusion. HPS was superior to CBL in teaching DKA and TS to final-year undergraduate pharmacy students.